Cover Image
close this book Grazing and rangeland development for livestock production
close this folder Management of rangelands and other grazing lands of the tropics and subtropics for support of livestock production. Technical Series Bulletin No. 23
View the document Preface
Open this folder and view contents I. Introduction
Open this folder and view contents II. Inventory of the natural resources base of permanent grasslands.
Open this folder and view contents III. Coping with constraints affecting forage production and utilization on rangelands, sod other Permanent Grasslands
Open this folder and view contents IV. The elements of productive grassland management.
Open this folder and view contents V. Measuring productivity of rangelands and other permanent grasslands.
Open this folder and view contents VI. Estimating Feed Requirements of Ruminant Livestock in Tropical and Sub-Tropical Regions.
View the document VII. Conclusions
View the document Appendices
View the document Appendix no. 1: Perennial Forage Grasses for the Tropics and Subtropics
View the document Appendix no. 2: Seed Characteristics and Adaptive Features of Forage Grasses
View the document Appendix no. 3: Major Forage Legumes for the Tropics and Sub-Tropics
View the document Appendix no. 4: Seed Characteristics and Adaptive Features of Forage Legumes
View the document Appendix no. 5: "Sources of Seed of Tropical Legumes"
View the document Appendix no. 6: Sources of Rhizobium Cultures for Tropical Legumes
View the document Appendix no. 7: Additional Publications Dealing with Livestock Production and Feed Supplies

Management of rangelands and other grazing lands of the tropics and subtropics for support of livestock production. Technical Series Bulletin No. 23


Prepared by: Howard B. Sprague

Agriculture Technology for Developing Countries

Technical Series Bulletin No. 23

May 1979


Office of Agriculture

Development Support Bureau

Agency for International Development

Washington, D.C. 20523



The rangelands and other grazing lands al the tropics and subtropics constitute enormous natural resources that have received scant attention of science and technology. They provide nearly all of the feed for ruminant livestock (cattle, sheep, goats and buffalo);; and deficiencies in feed resources profoundly affect the domestic supplies of milk and meat for herders and farmers, as well as the quantity of live animals for market. There appear to be substantial opportunities for improving the feed producing capacities of all grasslands, by the application of management practices found effective in developed countries. These practices should substantially increase the incomes of livestock producers. .

This bulletin undertakes to review the basic principles that underlie sound grazing land management; and to indicate the application of these principles for practical support of economic livestock production in the tropics and subtropics.


Dean F. Peterson


Office of Agriculture

Bureau for Development Support

Agency for International Development

Washington, D. C. 20523


Howard B. Sprague




I. Introduction

To achieve effective development of many tropical countries, livestock production must have a high priority. The recurring widespread droughts in many regions have clearly indicated that the production of forages for support of livestock often dominates the situation. Even in humid regions, forage production is generally deficient. Without adequate supplies of feedstuffs, the other management measures for efficient production, as well as for protecting animal health, improved animal husbandry, animal improvement, and marketing, are made ineffective.

The necessity of having adequate feeds to meet nutritional requirements of livestock must be recognized, not only for the seasons when rainfall fosters growth of herbage on grazing lands, but also for the dry periods when forage growth ceases. Ensuring adequate reserve supplies of feed in seasons when little or no plant growth is possible has long been recognized as a prime requisite for productive animal enterprises in the temperate zones of the world. There, the feed reserves include hay, silage and dry fodder for feeding during the winter period.

The comparable principle for the tropics and subtropics should recognize that livestock feeds must be provided for dry seasons when plant growth ceases. These dry season feeds may include protected grazing reserves, or feeds that have been harvested and stored for support of stock in these seasons. Unfortunately, violation of this principle is widespread in the tropics and subtropics to the great detriment of agricultural development.

1. Land Use and Livestock Populations

There are enormous potentials for improvement in feed production to support ruminant livestock enterprises in the tropics and subtropics. The permanent grasslands of the tropics and subtropics occupy about 2 1/2 times as much land area as all arable lands plus land in permanent crops (Table 1). These vast grassland areas are useful to man primarily through the support they give to livestock. Every country with extensive grasslands should be concerned with the most effective utilization of these lands and the means by which these forages may be produced and conserved. In addition, however, each country has need for the products of these lands as live animals, meats, milk, and hides and skins. The edible animal products are valuable for export; and the meats and milk products are indispensable for domestic human diets since they supply animal proteins which are deficient in the food supplies of virtually all tropical and subtropical peoples. These two needs are ample justification for intensified programs to effectively utilize these vast land areas and to greatly increase production of animal protein foods.

The difficulties that less developed countries have in producing enough staple foods to keep pace with growing populations are compounded by the low nutritive quality of the food supply, when insufficient quantities of animal proteins are produced. Substantial advances may be made by making more effective use of permanent grasslands, both to enhance economic status of individual producers and of whole nations, at the same time that the highly nutritious animal proteins are made more abundant.

Table 1. Land Use and Livestock in the Tropics and Subtropics


Number of Countries Included

Total(1) Arable Lands (Millions Hectares)

Permanent Grasslands (Millions Hectares)

Numbers of Ruminant Livestock (Millions of Animal Units) (2)











Central America and Caribbean





South America











(mil. Ha.)

(mil. Ha.)

(mil. A.U.) (2)

(1) Arable land includes those occupied by permanent crops (fruits, nuts, etc.).

(2) One Animal Unit (A.U.) - 1 bovine, buffalo, or camel; or 5 goats; or 5 sheep.

This technical paper undertakes to assemble and summarize available information on tropical and subtropical grasslands, with particular reference to their potential development and utilization. In a few regions there are notable examples of outstanding success in increasing the total forage production and nutritive values of permanent grasslands, with the result that animal production has been made more profitable. These isolated successes may be enlarged to encompass nearly all ranges and permanent grasslands.

In subhumid (savannas) and semi-arid (semi-desert) regions, the cushioning effect of prudent management against the impacts of the inevitable recurring droughts, has been demonstrated in terms of protecting livestock herds and fostering production of the forage plants that are adapted to the region.

Certain basic principles are illustrated in those isolated successes that are available for observation, and adapted to the varying conditions in specific regions. One basic premise underlies the following presentations namely, that the application of a complete package of superior practices will invariably be more rewarding than the application of individual practices. Wherever a complete package is not feasible, it is essential to undertake those treatments that are most essential to development of a situation on which future improvements may be added.


II. Inventory of the natural resources base of permanent grasslands.

Grasslands vary tremendously from region to region as a result of the natural resources present, as well as the cumulative effect of man's management practices. The basic natural conditions of climate, land forms and soil types, usually have been greatly modified by grazing practices that often have depleted potential vegetative cover, and dissipated rainfall in harmful ways. The low regard for grassland productivity that is widely prevalent has resulted in declining plant growth and lack of dependability in forage production under unwise management.

1. Climate.

Effective utilization of every kind of grassland must recognize and adjust to the conditions at hand. There is little that can be done to change climate; but man should be aware of the typical variability in each region in the amount of rainfall, its seasonal distribution, and the kind of rainstorms that occur. Another important climatic factor is the typical air temperature, particularly in the seasons of significant rains. In the tropics and subtropics, some regions are characterized by rains in cooler seasons, and in other regions by summer rainfall. Rainfall that comes in heavy showers normally tends to have high runoff losses, particularly on sloping lands on which soils with low permeability occur. Table 2 summarizes types of regions, in terms of average rainfall.

Climate controls the production of feedstuffs in the following ways:

a. Rainfall.

The rainfall that occurs, as to the total amount, its distribution through the seasons, and the character of rainstorms (gentle or sporadic downpours, and amount per storm), constitute a major climatic factor. The duration of the seasons without significant rain is highly important. The effects of rainfall are moderated by soil conditions and the nature of the vegetative cover. A cover of forage grasses and legumes provides a most effective means of retaining rainfall on the land where it falls, to infiltrate into the soil where it may be used by plants growing in the soil.

Table 2. Average Annual Precipitation

Total Yearly Rainfall

Descriptive Terms



Tropics & Subtropics



over 80

over 2000

Continuously humid


Tropical rain forest

60 - 80




Wet-dry tropics

40 - 60


Moderately humid


Mixed vegetation

20 - 60




Savanna, Steppe

10 - 20





0 - 10





(See Figure 1, for world distribution of rainfall zones.)

FIGURE 1. World Distribution of Rainfall Zones

b. Sunlight.

Sunlight in the tropics and subtropics, influences plant growth through the intensity of solar energy, the light quality (higher in ultraviolet rays than in temperate zones), and the length of daylight periods. Many tropical plant species are poorly adapted to the temperate zones which have longer days in summer and shorter days in winter. Thus, some entire plant species, and some varieties within widely distributed species are either adapted to temperate zone lengths-of-day, or to tropical zone lengths-of day (11 to 13 hours day length).

c. Temperatures.

Temperatures in the tropics and subtropics are not only generally higher than in the temperate zones, but the cooler season is usually warm enough to sustain plant growth throughout the year whenever rainfall is adequate. Night temperatures are relatively warm, except at higher altitudes where dissipation of daytime heat is quite rapid, particularly at elevations above 3000 ft. (- 1,000 meters).

d. Evaporation and humidity.

The rates of evaporation rise rapidly with higher temperatures so that considerably more rainfall is needed to maintain equivalent air humidity, than is needed in the temperate zones. The greater evaporation losses are accompanied by higher transpiration losses of water from plant leaves and stems. Even the humid wet-dry tropics, because of the extended dry season, produce substantial moisture stresses in plants.

Evaporation from free-water surfaces (lakes, ponds, streams), and from soils and the water losses directly from plants, are very high in warm dry situations. Growing plants must maintain a minimum water balance between uptake by roots and losses from leaves and stems, to remain active in growth and in storage of plant food reserves. Unless a positive balance is achieved, the plant ceases to function and either becomes dormant or dies, The length of the periods during which plants can function, is a fair measure of how much growth can be made in the course of a year, whether the growth be in foods and fiber used directly by man, or as forage for consumption by livestock. As the climate becomes more severe in terms of water balance for plants, the growing of crops tends to dwindle, and prime reliance is placed on forages (grasses, legumes and browse plants) that must support crazing livestock enterprises to yield products that man can use to meet his needs.

e. Length of the dry season.

A significant measure of the suitability of climates to support plant growth, is the average length of the dry season each year. For convenience in determining the regions where different species of plants are capable of surviving and making substantial growth, the following conditions are recognized:

1. Humid - having less than 2 1/2 months with little or no rainfall;

2. Intermediate-humid - having 2 1/2 to 5 months with little or no rainfall;

3. Intermediate-dry - having 5 to 7 1/2 months with little or no rainfall;

4. Semi-arid - having 7 1/2 to 10 months with little or no rainfall;

5. Arid - 10 to 12 months with little or highly variable rainfall.

The general geographic distribution of the dry seasons according to their average yearly duration is shown in Figure 2.

FIGURE 2. Length of the Dry Season

f. Monsoon climates.

The monsoons have a strong influence on plant growth of all types because of the effect they have on the seasonal occurrence of the rainy season. me basic causes of monsoons are poorly understood, but they can be predicted to some extent. They have considerable variability in the dates of beginning and their duration. The name "Monsoon" is Arabic, and was originally applied to the seasonal winds of the Arabian (Persian, Sea, that blow about six months from the southwest. The winds are caused by differences of annual temperature trends over land. Temperature changes are large over land, but small over oceans. The monsoon blows from cooler to warmer regions; from sea toward land in summer (bringing rains), and from land toward the sea in winter (without rains). Atmospheric pressure is relatively high in cooler regions and lower in warm regions, permitting air-mass movement to take place.

The monsoon type of air movement by seasons occurs throughout the tropics, and is perhaps better known in the Indian subcontinent than elsewhere. However, monsoon type climates are widespread in the tropics and subtropics. Monsoon winds blowing from oceans toward and across land masses of Africa and South America are important factors in producing the rainy season of those tropical climates; and the reverse flow of air masses from land toward the ocean causes the dry seasons. The periodicity of rainfall in the tropics is well established by rainfall records that are now available in virtually all developing countries.

g. Mediterranean climates.

These are produced by a unique combination of land forms, latitude, and monsoonal winds. Rainfall characteristically occurs in the cool months, and the summers are relatively dry. In the Mediterranean basin, and extending eastward to Iran, air masses flowing from the Atlantic bring rains in the winter period, thus producing a type of agriculture based on plant growth suited to the cooler moist winter season.

h. Categories of climates

(Figure 3). The categories of climate that recognize dominant characteristics may be identified as follows:

(1) Warm temperature and subtropical zones:

(a) Dry summer, Mediterranean climates with humid winters.

(b) Dry summer, steppe (subhumid) climates with humid winters.

(c) Steppe (subhumid) climate with short summer humidity.

(d) Dry winter climate with long summer humidity

(e) Semi-desert climate with short seasons when rains occur.

(f) Permanently humid grassland climates.

(g) Permanently humid climates with hot summers.

(2) Tropical zones:

(a) Tropical year-long rainy climates.

(b) Tropical humid summer climates

1) with humid winters

2) with comparatively dry winters.

(c) Wet and dry tropical climates.

(d) Tropical dry climates

1) with humid winters

2) with dry winters.

(e) Tropical semi-desert climates.

(f) Tropical desert climates.

*For representative data, see "Climates of the World," published by the U.S. Department of Commerce, and available from the Super intendent of Documents, U.S. Government Printing Office, Washington, D. C. (35c).

FIGURE 3. Seasonal Climates of the Tropics and Subtropics

The significance of these zones is that for forage production of the plant species adapted to a particular climatic zone will probably be useful in any other part of the world where there is similar climate.


2. Land forms and elevation.

The surface topography of lands, and their altitude above sea level, have pronounced effects on climates, and thus on plant growth. me principal classes of land forms are shown is Figure 4. However, within each of the land forms shown there are local variations in surface topography that have major significance in their suitability for growing crops, for production of forages on pastures and rangelands, and other uses. As the elevation of land increases the temperatures are lower, since the day-time heat is dissipated more rapidly after sundown at higher elevations.

Land elevation also modifies the rainfall substantially. Moisture laden air masses moving toward ranges of hills or mountains deposit rain as the air moves upward. However, on the leeward side of these uplifted land forms, the same air masses having lost much or most of their moisture vapor, do not contribute substantial precipitation. Thus, the eastern slopes of the Andes mountain of South America have abundant rains, and the western sides are quite arid. Similarly, the northern slopes of the Atlas mountains in North Africa have much more abundant rains than the southern slopes. The native vegetation as well as the crops, and the range and pasture lands, are profoundly affected by such changes in rainfall, generally becoming more abundant as rainfall increases.

FIGURE 4. Principal Classes of Land Forms

Within each of the principle classes of land forms there are important local variations in topography and in present agricultural use. In general, cropping tends to be concentrated on smoother land areas, less subject to erosion and rapid rainfall runoff, and with a deeper soil profile that favors root occupation. On other soil areas that are poorly suited to cropping, the lands are generally occupied by rangelands or pastures, except in humid regions where the vegetation is usually trees and forest. m us, in a single locality with humid wet-dry climate, or in a subhumid climate, the crop lands may be intermingled with less favorable lands that are grazed. In drier regions not favorable for cropping, all land classes may be used solely for grazing.


3. Natural vegetation as an index of agricultural potential.

The native vegetation of a region is determined very largely by the climate. The yearly impact of rainfall, temperatures, evaporation and humidity, and winds determine the types of vegetation that can survive and propagate. The nature of local soils modifies the climatic environment to some extent. Insofar as the native vegetation of an area may be discerned despite manes occupation and use of it, such vegetation may serve as an index of the combined effect of climate, land forms, and soil conditions to support plant growth. Native vegetation does not reveal what may be the conditions that limit plant growth, nor the extent that these limitations may be corrected by suitable treatments. 'where these plant resources have been depleted by severe over-grazing, or by uncontrolled burning, by uncorrected soil erosion by wind or water, it may be difficult to identify the natural vegetation.

Figure 5 shows generalized native vegetation zones on a global scale. Compare this map with the rainfall shown in Figure 1. As noted above, such vegetation may persist only in protected or isolated areas where cropping is nearly universal, or where severe overgrazing by live stock has largely destroyed the native vegetation. The natural vegetation zones are as follows:

Low latitude (tropical) forests

Tropical rain forest

Lighter tropical forest

Scrub and thorn forest

Middle latitude forest

Mediterranean scrub forest (subtropical)

Coniferous forest (north temperate zone)

Broadleaf and mixed forest (temperate zones)


Savanna (tropical)

Prairie (temperate zones)

Steppe (tropical and temperate zones)


Desert shrub and desert waste (tropical and temperate zones)

FIGURE 5. Natural Vegetation Zones of the World

The steppe Is predominately occupied by bunch grass and scattered shrubs. Following the occurrence of rains, any open ground surface is occupied by short season annual grasses and herbaceous plants.

It may be noted that the only vegetation zones that occur in both tropical and temperature zones are the steppe and desert shrub. Even in these zones, the tropical plant species are quite different from those of the temperate zones. The vegetation zones of the tropics are unique, which means that the research and technology needed to utilize them to support man cannot be transferred from one zone to another without considerable modification. Much adaptive research will be needed, as well as original research on specific problems, to fully exploit the potentials of the tropics. Subsequent sections of this report summarize present knowledge on the adaptation of superior forage grasses and legumes to different environments, and their management and utilization by livestock to produce economically attractive returns.


4. World soil grouping for forage production.

The characteristics of the major soil groups of the world are determined partly by the climates in which they occur, partly by the geologic material (rocks, sediments, etc.) from which they have evolved, partly by their geologic age (very old weathered soils are quite different from recently deposited alluvial or volcanic soils), and partly by the vegetative cover under which the soils have developed in recent centuries. Soils may be classified by their own characteristics (color, texture, depth, composition, etc.), but their economic value depends on their suitability for growing plants.

a. Tropical soils.

Tropical soils are unique in many respects because of the climatic conditions under which they have developed. me effective management of tropical soils must recognize the properties of each distinctive soil group, and adjust the land utilization practices to protect the type of plant growth that they will support on a continuing basis. The following major soil groups are recognized by soil scientists.

b. Major soil groups.

The seeming endless diversity of tropical soils can be resolved into major groupings on the basis of their predominant characteristics. The following classification is useful, which also are shown in Figure 6.

Great Soil Groups of the Tropics and Subtropics*


Total land area in millions of hectares

1. Dark Grey and Black Clay Soils(inclusions of chernozems, red dish chestnut soils, and hydromorphic soils)


2. Sierozones, Desert and Red Desert Soils (inclusions of lithosols, regosols, and saline soils)


3. Latosols, Red-Yellow Podzolic oils (inclusions of hydromorphic soils, lithosols, and regosols)


4. Red-Yellow Mediterranean Soils(inclusions of terra rosa soils, some mountainous areas, and many areas of rendzina soils)


5 Soils of Mountains and Mountain Valleys (inclusion of many lithosols)


6. Alluvial Soils (Includes innumerable areas in all regions, that are included in other soil groups. These soils have been estimated to support 25% of the world population. Alluvial soils are formed by sediments from flowing waters in river and stream valleys and deltas, and in intermit tent channels of rainfall runoff in watershed basins. These soils lie in the present day flood plains of these waters, or as terraces and benches of earlier geologic periods.)


*Derived from article by C. E. Kellogg and A. C. Orvedal, published in "Advances in Agronomy" Vol. 21, 1969, by Academic Press, New York.

The major soil groups are shown in Figure 6. This map may be useful in connection with the data given in Table 1, which reports a total of 1,582 million hectares of "permanent grasslands" in the tropics and subtropics, in contrast to 626 million hectares of arable lands used for tilled crops and tree crops of various kinds. Comparatively little research has been done on soil management of grazing lands that support livestock, in contrast to the studies on soils for crops. Enough information has been collected, however, on rangelands and other grazing lands to indicate that the potentials for improvement are often very substantial.

Most upland tropical soils that are cropped are low in organic matter, since the high temperatures foster rapid decomposition of roots and other plant parts that account for production of soil humus in temperate zones. Perennial grasses and legumes on tropical and subtropical grasslands make yearly contributions of fresh organic matter within the soil profile and at the soil surface, thus improving soil permeability to rainfall and recycling minerals from plant tops back into the soil profile. However, any characteristic mineral deficiencies of a soil type must be recognized and corrected by suitable treatments to more fully exploit the forage producing potentials of rangelands and other perennial grasslands.

FIGURE 6. Generalized Soils Map of the World

The basic philosophy is that man either adjusts land management practices to the inherent cap abilities of soils as they occur, or he identifies those limiting factors that can be altered by applications of modern technology, and exploits those opportunities that are economically feasible. Man cannot change the climate, but he can make the most effective use of rainfall, temperatures, and humidity that may be expected to occur. Protection of native forage plants is a first requirement, but introduction of superior adapted forage plant species may also be rewarding.

c. Soil deficiencies and plant growth.

Plants grown on different soils in the same climatic zone may make quite different amounts of growth as a result of some important soil factor or factors. Moreover, the nutritive values of forages grown on deficient soils are often much reduced from the status when grown on more fertile soils. The most encouraging aspects of soil deficiencies are (1) that there are practical methods for determining the presence of such limiting factors, and (2) many of these limiting factors can be altered by man to produce benefits in terms of increased forages for livestock that are much greater than the costs of to practices or treatments. These will be discussed in more detail in a later section of this report.

d. Dependence of plants on soils.

Favorable soils must be suitable for root occupation as to soil permeability and aeration and have good soil moisture relations (permeable to rainfall) with favorable texture and structure to store rains in the soil profile for subsequent uptake by plant roots. Also, soils must supply all of the mineral nutrients required for plant growth. These include the major elements: nitrogen, phosphate and potash; and the secondary elements: calcium, magnesium, and sulfur. In addition, there should be a modest supply of the minor elements required in "trace" amounts for normal growth: zinc, boron, molybdenum, copper, iron, and macanese. Further, the suitability of soils may be altered by excessive alkalinity in dry regions, or acidity in humid regions.

e. Laterites and laterite soils.

In the tropics, a unique soil formation often occurs, known as laterite. Laterites are characterized by very high contents of iron and aluminum oxides. There are several forms of these reddish soils, which differ markedly in their characteristics and agricultural usefulness: (1) There is the ground-water laterite which has a layer (horizon) indurated with iron compounds, and thus with Low permeability to rainfall. It may be very thick and can be formed on any parent rock material and drainage conditions under the typically high temperature of the tropics. (2) A second type is a deep red soil rich in iron and aluminum, which Is only formed by weathering of basic igneous rocks under conditions of good to moderately good drainage, in regions of seasonally high rainfall. They nearly always show signs of impeded drainage in the subsoil. There is a soil horizon containing small pea-sized laterite gravel concretions, whose concentration increases with increasing amount of impedance in the internal drainage. Below that layer is a deep reticulated mottled red layer, which may be soft in continuously humid regions, but dries out to hard lumps when exposed to drying weather. The hardened types of laterite near the around surface are often quarried for use as road building material. The indurated laterite soils are generally considered non-arable, and are occupied by brush and scrubby tree growth, interspersed with some grasses and legumes that may be grazed. Research on how to improve laterite soils for forage production has yet to be done.

5. Characteristics of permanent grasslands.

There are a variety of reasons why the "permanent grasslands" are not now cropped (See Table 1). In the semi-arid and subhumid regions, the rainfall is too uncertain to make cropping successful under natural rainfall. Only the deeper soils with good rainfall storage capacity, that are inherently fertile are cropped in regions of limited rainfall. Other soil types that are too shallow, or are highly erosive and badly gullied, or are stony, or poorly drained, or infertile for any other reason (such as laterite soil areas that are relatively impermeable to rainfall), are relegated to native vegetation. To the extent that the plant growth on such soils is feasible, these areas are used as grazing lands.

A notable exception to the above types of "permanent grasslands" are the tsetse-fly infested areas across Central Africa, that are estimated at some 10 million hectares. These lands now are largely unoccupied by man because of the trypanosomiasis (sleeping sickness in man, N'gana in livestock) carried by tsetse-fly as it feeds on man and animals. As the tsetse-fly is controlled on these lands, they will become available for cropping where soil conditions are favorable, and for grazing on nearly all soils.

It should not be assumed that perennial forage grasses and legumes have no role on cultivated lands. Rather, they are most productive on lands and soils commonly used for crop production. The use of planted forages is crop rotations, or as longer term occupation of arable soils, as a type of profitable enterprise in farming systems is discussed in some detail in Technical Series Bulletins No. 13, 19 and 20 (see Appendix). Such planted pastures provide essential year-round livestock feed for animal enterprises in integrated crop/livestock farming systems. They contribute strongly to maintaining soil fertility under continuous cropping. Where such improved grazing lands are available they should be managed in conjunction with the associated grazing lands that are not used for crop production.

6. Soil surveys and land capability classes.

Some progress has been made in various regions in making soil surveys to determine the location of specific soil types, and in preparing soil maps of these, area by area. Some soil survey maps are quite detailed, but most of these in the tropics are of the reconnaissance type showing general soil conditions. Such maps are immensely useful in determining the characteristics of soils for crop production, as well as for producing grazing and harvested forage for livestock. The identity of soil types and grouping of these provides a means of exchanging information on soil improvement and management between countries and regions, thus facilitating the accretion of knowledge for the benefit of agricultural development whenever similar soils occur.

Another exceedingly useful classification of soils, that may be usefully applied where detailed surveys have not been made, is the land capability classification. These classes are based on land slope; soil depth and drainage; susceptibility to erosion; water and nutrient supplying power of the soil for plants; and the presence or absence of stone, hardpan or other impervious layers; any excessive salinity, acidity or alkali; and similar characteristics. These classes embrace all soil types and conditions, and therefore are applicable worldwide.

Land capability classification (indicating suitability for specific agricultural uses).1

(1) For detailed criteria, see "A Manual on Conservation of Soil and Water," U.S. Department of Agriculture Handbook No. 61.

a. Lands suited for cultivation, and for forage production.

Class I. Very good land, with wide usefulness. Excellent for cropping, and also for grazing and forage production. Land is level to moderately sloping. Low susceptibility to erosion. Soil deep, well drained, fertile and productive.

Class II. Good land. Useful for cropping, but should have soil conservation management to protect against degradation. Land has gentle slopes, only moderately susceptible to erosion hazard. Soils moderate in depth, good water relations, and fairly productive; supports strong growth of forage grasses and legumes for grazing and for harvest.

Class III. Moderately good land. Requires more intensive soil and water conservation practices to support sustained crop production. Inclusion of perennial grasses and forages in the farming rotation usually needed to protect against land degradation. Well suited for permanent grasslands to support livestock enterprises.

Class IV. Fairly good land, but not suited for tilled crops because of steeper slopes and other soil conditions, such as erosion and excessive runoff of rainfall, shallow soils, etc. Best use is for tree crops and for permanent grasslands. Productivity of land may be sustained by suitable management practices, under such usage.

b. Land capability classes not suited for tilled crops.

Class V. This class includes land not suited for cultivation but capable of supporting perennial vegetation (grazing or forestry) with few limitations from a soil conservation standpoint. The land may be nearly level. It includes lands on which vegetation has been depleted by misuse; and restrictions on use are needed to improve the vigor of the vegetation. Class V also includes many of the swampy areas that cannot be drained easily, as well as relatively level lands that are too shallow or stony to be used for crops.

Class VI. These lands are subject to moderate limitations under grazing or forestry use. It is too steep, subject to erosion, or too shallow, wet, or dry for cropping, but with careful management is suited to either crazing or forestry. It may be tilled Just enough to establish pastures. When used for grazing, there should be adjustment of animal stocking rates, so as not to exceed the forage producing capacity. Other necessary range management practices include deferred or rotational grazing in the season of rains to permit periodic recovery and natural reseeding of forage plants, and to protect against excessive depletion of plant vigor. Special measures usually are needed to control gulling; and water spreading by contour furrowing or other soil structures may be used to carry runoff water to less sloping land where infiltration and water storage in soil profile is feasible.

Class VII. These lands are subject to severe limitations or hazards under either grazing or forestry use. It includes lands with severe moisture deficiencies (semi-desert to desert); and lands that are very steep, eroded, stony, rough, shallow or otherwise unfavorable, that can be used successfully without degradation only if carefully handled. Because of these limitations, the productive capacity is only fair to poor for grazing (requiring carefully controlled stocking rates); and areas allocated for forestry must be protected from virtually all grazing.

Class VIII. These lands have such unfavorable characteristics as to be unsuited for cultivation, grazing, or forestry. Their principal values are for wildlife or for watershed protection uses. Class VIII lands include deserts, marshes, badlands, deep gullied areas, high mountain land, and very steep, rough, stony or barren land. They often occur in small areas, but elsewhere may be quite extensive, as dry hilly areas, or moving sand dunes. Any management practices are usually limited to those necessary to protect adjoining lands that have greater economic values.

a. Lands suited for grasslands.

It should be noted that permanent grasslands may constitute a productive use of all land capability classes except Class VIII. Perennial grasslands for support of livestock are an optional use of land in Classes I-III. Classes IV-VII have potential as managed permanent grasslands. The full use of all land resources of a country or a region will certainly involve substantial land areas that are unsuited for tilled crops. me important consideration is to devise management systems that will make the most profitable use of each type of grasslands, for grazing and for production of harvested forage (as hay or silage).

7. Present land use patterns, by ecological zones.

a. Dry rangelands in semi-desert zones.

The predominant controlling factor for such lands, is the limited amount of annual rainfall and the uncertainty as to when it will occur. There is little or no crop production in this zone, except where localized irrigation from shallow wells is feasible. Much of the land fed by natural rainfall is partially occupied by forage and browse plants, with open ground between plant clumps. After a period of showers, this open around may be occupied briefly by short-season annuals, that quickly produce seed and die. The total amount of palatable forage for livestock is usually quite limited, but is greatest on areas of permeable soils on which runoff of rainfall is not rapid, and there is opportunity for rains to infiltrate into the soil profile where much of it is stored for subsequent uptake by plant roots.

Most of the rangelands in regions of limited and uncertain rainfall are not now being managed to fully develop their potential for producing forage and supporting livestock enterprises. Too often there is severe and ruinous competition between herdsmen for limited supplies of forage and water, during relatively short grazing seasons. Such a situation is not conducive to learning the principles of rangeland and livestock management by trial and error. This may explain the almost universal overgrazing, caused by overstocking the rangelands, which severely damages the vegetation and the soils, particularly in semi-desert regions in periods of protracted drought.

The pity of such damaged rangeland is that recovery is very slow even when grazing pressure is reduced, and the real potential for support of livestock is never allowed to develop.

It is probable that the vast areas of drought plagued lands of Africa, the Near and Middle East and elsewhere could be made continuously far more productive than it has been In recent decades; and that methods of cushioning against recurring droughts can be made effective. These management principles will be detailed in a later section of this report. The implementation of basic principles must be compatible with the social, economic and political situation In each country, with such adjustments as will permit full exploitation of climatic conditions, land and soil capabilities, the strengthening of plant growth, and the reduction of unnecessary runoff of precious rainfall. However, a first step would be recognition of the basic principles of managing the natural resources, and the rewards that will follow prudent management. Changes in social, economic, and political policies may be feasible once the economic benefits of improved management become visible.

b. Savanna lands.

These occur in subhumid regions, where the natural vegetation consists of forage grasses and legumes, interspersed with variable amounts of bush and scrubby trees. Overgrazing and uncontrolled burning have usually damaged the palatable vegetation and permitted the bush and scrubby tree growth to dominate. Throughout the savanna regions, crop production occupies the localized soil areas that are fairly deep and capable of storing rainfall to support crop growth Millet and other short-season crops predominate in drier regions; sorghum replaces millet where moisture is more adequate; and maize replaces sorghum where rainfall permits a longer growing season.

Intermingled with soils that will support cereal grain production and other food and cash crops (foodgrain legumes, oilseed crops, root crops, etc.) are lands that are better suited for permanent grasslands. Usually, attention is concentrated on the crop lands, and the grasslands receive little consideration. In general virtually nothing has been done to improve the productivity of the grasslands, but important potentials do exist. At present, village communal herds of livestock are grazed on any grasslands within reach of villages. The herds are composed of family owned animals, but there is little concern as to the effect of grazing practices on forage production, and there has been no effort to improve the vigor of forage plants and their nutritive value. Even less consideration is given to the production and preservation of forage to carry livestock through the long dry seasons when forage grasses and legumes are dormant.

The livestock enterprises in savanna lands are crucial to the supply of meat and milk required by villagers; but the goats, sheep, cattle, and camels are used largely as scavengers for any available forage, rather than as farming enterprises to more fully utilize the natural resources available. m There are important unused opportunities for mixed farming systems,* in which both crop and livestock enterprises are combined to produce balanced farming systems that are more productive than systems that depend solely on crops, or solely on herded livestock. A first stage may be the inclusion of perennial grass-legume forages for one or two years in a five-year cropping system, to maintain productivity of the land as well as to provide feed to support livestock during the dry seasons. This would permit marked improvement in livestock reproduction and growth, and in milk production.

*See Technical Bulletins 19 and 20, listed in the appendix of this bulletin.

A major factor in subhumid regions in utilizing all types of permanent grasslands most effectively is the absence of any system that would place the management of these resources firmly with the major users, so that the benefits from good management, and the penalties for poor management that result in lowered productivity, would be felt by those users. Under the current situation (with unfenced and uncontrolled grazing on lands), the permanent grasslands are largely neglected, and subject to overgrazing and other mismanagement that degrades productivity of the lands, and causes severe damage to the rangeland that could be avoided.

There are important opportunities in subhumid (savanna) regions to produce and preserve the forage needed to carry livestock through the tong dry season when there is not plant growth. These include the following:

(1) Reservation of grassland areas left ungrazed in the season of rains for use during the dormant dry season. The areas thus reserved should be large enough to feed livestock until the subsequent rainy season occurs. Such standing forage gradually declines in nutritive value during the dormant season, but will contribute significantly to a sustained feed supply.

(2) Harvesting forage that is surplus to grazing needs during the growing season, and preservation as hay. If cut before the grasses produce seed heads, the forage has good nutritive value. Such forage is quickly dried in the field, and this hay may be stored indefinitely if protected from rain and termites.

(3) Harvesting forage and preserving it as silage. There is little or no loss from shattering-off of dry parts in making silage, such as occurs in making hay; and the feed value is high if silage is properly made. The green forage is chopped in lengths of 2 to 5 cms., and packed tightly in well-drained trench silos, covered with impervious polyethylene sheeting, and allowed to ferment until cured, and remain in place until fed. Exclusion of air is essential for fermentation and preservation. When properly made, grass silage preserves as feed, the maximum percentage of the green harvested crop.

It should be noted that hay and grass silage may be produced as a crop on tilted land, or these forages may be harvested from permanent grasslands. It is feasible to produce surplus forage by these means, that can be used to feed livestock brought in from semi-desert areas in the dry season.

c. Wet-dry tropics.

Lands on which tree growth has been cleared, but which are not occupied by crops because of erosion or declining fertility, are capable of producing relatively high yields of nutritious forage. Well menaced grasslands should not suffer erosion. The seasons of abundant rains usually occupy six to nine months, during which adequate growth is made on grasslands for grazing. There is normally a season when forage growth exceeds grazing needs, and the surplus forage at that time should be harvested and stored as hay or silage, at the growth stage when the feed is most nutritious. Such feed should sustain the ruminant livestock during the dry season, both for reproduction and growth, and for sustained milk flow in all seasons.

The potential for forage production on all lands in the wet-dry tropics, greatly surpasses that possible in subhumid, and semi-desert areas. When soil deficiencies are corrected, and adapted forage grasses and legumes are established, livestock production may constitute a stable and profitable form of agriculture. Such lands may be effectively used to grow and finish meat animals for market, that are moved from drier regions after the grazing seasons in those areas is terminated because of lack of feed.

d. The humid tropics .

Usually have abundant rains for nine or more months, and thus have relatively short dry periods. Perennial forage grasses and legumes adapted to such climates and capable of flourishing on soils of these regions, may provide fresh forage throughout the year. The deeper rooted forage species will continue growth in dry periods on moisture stored in the soil profile. However, any surplus forage that is present on lands at the beginning of the normal dry season may easily be made into hay or grass silage to sustain ruminant livestock during the short dry seasons.

One of the major advantages of forage grasses and legumes on cleared land in the humid tropics, is that such forage plantings made in rotation with tilled crops, will greatly assist in maintaining continuous soil productivity, without the obsolete method of resting land for several years to allow native growth of trees and vines to partially restore fertility.* Forage planting may constitute a necessity for sustained crop production; and this would greatly increase the total land areas available to feed the rapidly growing populations in developing countries.

*See Technical Bulletins 19 and 20, listed in the appendices.

Forage plantings also are useful means of utilizing lands that have been damaged by gulling and erosion, or have other limiting characteristics. Forages may vow well on cleared lands that are unsuited for cropping.


III. Coping with constraints affecting forage production and utilization on rangelands, sod other Permanent Grasslands

1. Climatic constraints.

The first step Is to acquire information on the average status of weather conditions to be expected in a specific region, on the basis of accumulated weather records. m These data will include seasonal and total rainfall, seasonal temperature means and extremes, air humidity and evaporation rates, cloud cover and important prevailing winds. m These climatic conditions dominate the environmental controls of plant growth in semi-desert regions, and are of major importance in subhumid regions, but are less significant controlling factors in wet-dry humid tropics, and in the continuously humid tropics.

Attempts to control climate have not been fruitful, but much can be done to cushion against the adverse effects of those conditions that retard or inhibit growth of forage plants. m us, conservation of limited rainfall in dry regions through management practices that improve infiltration of rainfall into the soil profile for storage and use by plants, and the husbanding of forage growth made in moist periods for consumption by stock in dry seasons, are two examples. In humid climates, the choice of palatable productive forage species that are adapted to both the higher rainfall and to the soils that occur in such regions; are important measures for adjusting to excessive rainfall and high air humidity.

Even in semi-desert regions, the choice of forage species that survive from year to year and produce substantial forage when rains occur, is an adaptive measure within the capability of man, that has only begun to be used in the tropics. Yet there is good evidence from rangelands of Australia and some other countries that introduction of drought resistant species is effective. It is clearly evident in all climatic regions (semi-desert, savanna, wet-dry tropics, and humid tropics) that the native forages may be effectively supplemented by well adapted species discovered in other parts of the world, to substantially improve the capacity of these lands to support livestock. However, more efficient management of natural forages should be considered a necessary stage to precede introduction of improved forage species from other regions.

2. Soil degradation.

In regions of limited rainfall, the depletion of the forage grass and legume cover by overgrazing results in surface soil compaction that reduces infiltration of rainfall into the soil, and increases the runoff and loss of precious water. Overgrazing also reduces forage plant vigor, and the depth of occupation of soil by plant roots. The weakened root development on enfeebled forage plants results in degraded internal soil structure and the impaired capacity of the soil profile to store rain water for subsequent use by forages.

The weakening of the vegetative cover provided by forage grasses and legumes often fosters severe gulling of land and sheet erosion of soils, particularly in semi-desert and savanna regions. Overgrazing sets in motion the process of soil degradation that often causes irreversible damage. The top soil losses from erosion, whether by water or by winds, removes the more fertile soils and exposes relatively infertile subsoils.

3. Depletion of plant cover.

a. Loss of perennial forage plants.

Overgrazing by excessive numbers of livestock, reduces tip growth and weakens individual plants. Perennials survive and maintain vigor only when allowed to make regrowth periodically, and to produce seed and establish new seedlings. Uncontrolled burning has much the same effect as overgrazing, and the damage to forage plants is compounded by combining burning with subsequent overgrazing that prevents plants from making necessary regrowth.

b. Invasion by bush and tree growth.

Invasion of grazing lands by woody bush and scrub growth that has little forage value is serious, but is reversible. These useless invaders are native plants that propagate rapidly where forages are weakened or killed by uncontrolled grazing or burning. While it is often true that some of the invading woody types of plants are legumes--capable of meeting their own nitrogen needs by root nodules, they have serious weaknesses for the livestock man. Their feed value is limited in amount and accessibility to grazing livestock; their root systems are deep but contribute very little nitrogen to the associated grasses; they are decidedly inferior in controlling gulling and sheet erosion of land, and they compete strongly with more desirable forage plants for light. The invasion of any grazing lands by unpalatable brush and scrubby trees, whether in regions of limited rainfall or in humid regions, indicates a deterioration of the feed producing value of grazing land, that should be countered by positive management practices.

c. Loss of forage legumes.

An important type of degradation that is frequently unnoticed is the loss of native leguminous forages. This is quite serious; such legumes are usually highly palatable, nutritious, and a major source of mineral nutrients that are indispensable to reproduction, growth of young animals, and milk flow. Moreover, such legumes are the prime source of nitrogen in most grasslands, which is "fixed" by root nodules by drawing on nitrogen in the soil air to produce proteins in all forage plants. Destruction of legumes by overgrazing is much more rapid than loss of grass cover, and such loss cuts off the major source of nitrogen for the rangeland or other permanent grasslands. Since it is rarely feasible to apply nitrogen fertilizers to grasslands particularly in semi-desert or savanna regions, the loss of legumes results in a sharp decline in capacity of the grasslands or rangeland to produce forage, and a similar decline in the nutritive value of the forage and in productivity of livestock herds and flocks.

For virtually all ecological conditions, there are forage legumes that are adapted to local conditions of climate and soil, and will survive and multiply under careful management. This potential is astonishingly effective where legume protection and management has been followed. It is highly unlikely to occur however, without the skillful intervention by man in managing his grazing lands.

d. Shortened grazing season.

The decline in periods of active growth of desirable forage grasses and legumes (and of browse* plants in very dry regions) is a consequence of those management practices that reduce vigor of the important forage plants. The most rapidly invading plant species on weakened grazing lands are usually weedy annual plants that have limited forage value and short growing seasons. The total plant cover may seem adequate at certain seasons, but when the grazing lands are examined closely to observe whether or not the better forage species are declining in abundance, the true status may be diagnosed. Early action to correct harmful management practices should be taken. The greater the deterioration, the more difficult and time consuming will be the restoration and recovery process. The most difficult problems are those of semi-desert rangelands; the next most difficult are the permanent grazing lands of the savannas. The present status of grazing lands in most tropical and subtropical regions of limited rainfall is rarely a natural condition. Instead, it is a condition resulting from long sustained and severe mismanagement. Until this fact is demonstrated by practical means, there will be little enthusiasm by herders for Improved management of grazing lands.

*Browse plants are generally woody bush, brush and short trees, that provide feed as leaves or smaller branches or twigs. Browse is a major type of feed for camels, goats and sheep, but has minor value for cattle. Browse is richer in protein and minerals than mature grasses, and it supports browsing animals when grass forage is in short supply.

4. Unbalanced animal nutrition on depleted grazing lands.

a. Reduction in feed supply.

A first consequence of mismanagement of grazing lands is reduction in total feed supply. When this reduction In forage growth is accompanied by increased numbers of grazing animals, the results may be disastrous. This is evident whenever there is the Inevitable recurrence of sustained deficiency in rainfall in regions that are characterized by limited and uncertain rainfall. A drastic reduction in forage growth causes grevious losses in livestock, because no provision has been made for such an occurrence. Livestock numbers that increase in years of abnormally abundant rainfall must be rapidly and drastically reduced when feed supplies dwindle, if disaster is to be averted.

There are various means of coping with reduced forage growth: (1) reservation of grazing areas to be used only when the need is acute, to provide supplemental feed; (2) moving animals quickly to areas where preserved feeds (hay or silage has been harvested and stored for such purposes; (3) reduction of livestock numbers by marketing all animals that cannot be supported by visible feed supplies, and completing marketing promptly before weight losses become serious. It is assumed that the active breeding herd will be protected at times when the herd size must be drastically reduced.

b. Reduced nutritive value of forages.

Certain nutritional deficiencies in feeds for ruminant livestock maintained on grazing lands are the result of mineral deficiencies in soils. Phosphorus is often widely deficient in forages of semi-desert and savanna regions, because the soil content is low. This is aggravated by the predominance of forage species (mostly grasses) that have low phosphorus contents. The introduction of forage legumes that accumulate phosphorus from the soil is often useful. A more positive practice that has been proven quite effective on rangelands of several continents is to provide stock with mixed salt-mineral mixtures rich in phosphates. A more sophisticated practice is the addition of soluble phosphate compounds to drinking water. Correction of phosphate deficiency by any means results in more effective utilization of forage; it improves reproduction and growth of grazing stock. The calcium and magnesium content of forages grown on acid soils in humid regions may be deficient from the standpoint of live stock needs, but this is less likely to occur in semi-desert or savanna grasslands. The content of certain essential "trace" elements needed in very small amounts by both plants and animals may be below acceptable levels in forages. These deficiencies result from the soil's low content of such "trace" elements as boron, zinc, copper, molybdenum, manganese, and iron. Cobalt also is highly essential for livestock, but not for plants.

As the inherent deficiencies of specific soil areas for individual "trace" elements are identified, their correction may make spectacular improvements in the vigor and productivity of the grazing livestock. Some soil areas are deficient in one element; and others have different deficiencies. In some regions where "trace" element deficiencies were suspected but not individually identified, the supplying of a mixture of all essential trace elements in a general purpose mixture with salt has produced great improvement in livestock performance, and resulted in more efficient use of available forages.

In general, the leguminous forages tend to be richer in all minerals that are essential for livestock, as well as being higher in protein content, and generally are more palatable and nutritious than other types of forage. Those management practices that foster an increase in forage legumes in the available herbage generally improve the value of the feed for support of livestock. This is so important that in some regions (Australia, for example), the entire grassland improvement program is built around the forage legume component.

The most sensitive segment of livestock herds to any nutrient deficiencies (protein, phosphorous, calcium, magnesium, and the "trace" elements) are the breeding females, lactating animals, and young stock. The rates of conception and reproduction, growth of the young while nursing, and weight gains after weaning are significantly improved by access to feeds with adequate mineral content. Older animals are less affected.

5 Overstocking and overgrazing.

Overgrazing that weakens the forage producing capacity of grasslands is caused by failure to estimate the amounts of forage that will normally be produced by lands in the climatic zone where located, and insistence on carrying larger herds and flocks than may be adequately fed on a year round basis. This practice is less ruinous in cycles of increasingly adequate yearly rainfall. The greatest penalty comes in cycles of decreasing rainfall, when feed supplies fail and stock starve and die, or succumb to diseases, or stock become emaciated and finally are sold at ruinously low prices. The breeding herd always suffers the greatest losses.

The question may well be asked: Why are livestock populations not kept in a more rational balance with forage supplies! To some extent, the answer is that the principles of sound grassland management have not been transferred to less developed countries. A more fundamental reason is that the herders have no firm attachment to specific grazing lands. These lands are open to all, and the herders vie with others to put stock on grasslands and consume it before others arrive. The competition occurs without regard to the resulting long-term damage to forage producing power of the lands.

Any undertaking to improve the productivity of rangelands and other permanent grasslands for the support of livestock enterprises must not only invoke sound technology but also provide incentives to the people directly involved. Methods must be developed for providing a continuing proprietary association of the using people with the lands needed to support their livestock. The relationship of people to land must be such that the benefits of good management and of improvements and restoration practices will be enjoyed by the people directly concerned; and the penalties for failing to conserve and husband the grassland resources will fall on these same people. This will be a far cry from the present situation where no persons or agencies carry responsibilities for rangelands and other grasslands that are grazed on a communal basis.

It should be possible under the social systems of each country to give specified groups of people (villages, ethnic groups, etc.) prior and exclusive rights to use of well defined grazing land areas, even where ultimate land ownership rests with the government. me government in such cases must accept responsibility for insisting on sound management of these grazing lands to strengthen the economy of the nation, as well as to reduce the hazards of economic disaster for the herdsmen.

6. Lack of stored feeds, and/or reserved grazing lands to support livestock in dry seasons.

Figure 2 in an earlier section, shows the duration of dry seasons, when plant growth ceases. This varies from 7½ to 10 months in semi-desert regions, from 5 to 7½ months in savanna (subhumid regions, from 2½ to 5 months for the wet-dry tropics, and from 0 to 2½ months for the humid tropics. Forage plant growth may continue for a few weeks after rains cease, on certain deep soil types that will store considerable water in the soil profile. For the most part, however, livestock must survive on the scanty forage (usually of low quality) left standing as dried growth. Under these conditions all animals lose weight, females fail to conceive or produce young under nutritional stress, lactation ceases, and prematurely weaned sucklings are stunted.

This problem of herdsmen in tropical and subtropical regions is similar to that of farmers in temperate zones where there are long winter or cool season periods when no plant growth is made. The logical solution is the same in both environments - to harvest and store feeds produced during the growing season to sustain livestock in plant-dormant periods. For poorly understood reasons, this method of supporting livestock with stored feeds during dry seasons has not been recognized in the tropics and subtropics.

It is entirely possible to make hay and/or silage during the plant growing season to sustain animals during dry periods when no new forage is being grown. For the individual herdsmen or farmer, he may either choose to produce stored feeds, or move his stock to regions where feed is available. There is no evident need to follow the common practice of slow starvation. It is not difficult to determine feed requirements per kilo of animal weight for the average duration of the dry season (see later section). This is basic information that might well be provided by government agencies to guide livestock producers.

This does not rule out special relief measures in periods of disasters, when feeds must be moved in to protect starving herds. In such cases, government intervention (with or without external assistance) is required; and it has been found effective to supply concentrated feeds such as oilseed cake or meals, and mineral supplements containing salt, phosphate, and essential "trace" minerals. Relatively small amounts of such feedstuffs enable ruminants to utilize lowgrade roughages that have little feed value otherwise. The goal however, is to prevent disasters by anticipating probable feed needs, and by storing some reserve feed supplies for emergency use.

7. Uncontrolled burning.

Controlled burning to reduce occupation of rangelands by woody bush and scrubby trees may be useful, when it is done under conditions that minimize any damage to desirable forage plants, particularly grasses and herbaceous legumes. However, the yearly burning, that is widespread in savanna lands and occasionally in semi-desert rangelands of the tropics and subtropics, is destructive, and contributes to continuing degradation of such grazing areas. Indiscriminate burning during the dry season is practiced by herdsmen for the sake of the short-term benefits of nutritious green grass that may be grazed soon after the rains begin. When there is no control; fires are started and allowed to burn as long as dry plant material is available.

By contrast, controlled burning is allowed when the fire will destroy the maximum of useless woody growth and do the minimum amount of damage to desirable forage species. Fires should be allowed only when winds and humidity are favorable on the selected areas, and where fire control is made feasible by firebreaks or natural barriers. Controlled burning is beneficial only when it constitutes a conservation measure, and on limited areas to minimize danger to wildlife and domestic livestock. It must be directed by specialists who are skilled in using this drastic practice. It should be prohibited at the hands of herdsmen


IV. The elements of productive grassland management.

1. Adjusting livestock numbers to match year-round feed supplies.

a. Identifying available grazing areas. The first requirement is to designate the rangeland areas open to specific herdsmen and their stock. The common practice of allowing any herdsmen who arrive first to use the forage for his herds should give way to assignment of specific grazing lands to designated groups of herdsmen. This is doubtless a government function.

b. Probable feed supplies. The probable forage producing capacity of these specific grazing lands may then be estimated, with revisions each year to adjust to apparent forage plant vigor. The number of animal units authorized to use these grazing lands may then be determined. Some flexibility is permissible if there are supplemental feed sources that the herdsmen may use. For example, if it is determined that the feed supply on a specific rangeland area will carry 100 animal units* for 12 months (or 1,200 animal unit months per year), the herdsmen may graze more animal units for a shorter period, but the total permissible grazing pressure must not exceed 1,200 animal unit months per year. The herd size must be adjusted to stay within the allowable number, by one of several methods, such as removal of livestock to other feed sources, or sale of merchantable stock, and additional reduction if necessary, by culling the breeding herd.

*One animal unit = 1 bovine, or 5 sheep, or 5 goats.

c. Selecting grazing land units for developing a grazing system. Dividing the total grassland area into several sectors, and grazing these in rotation, is a useful method of maximizing feed production and utilization without degrading carrying capacity of the grasslands. The yearly sequence of crazing the several sectors should be rotated, so that every sector will be protected every three to five years for production of seed and seedling establishment. The feeding of salt-mineral mixtures as needed to supplement the grazed forage usually increases the feed value of native plants.

d. Balancing livestock numbers in relation to available feed supplies. The yearly balancing of the grazing animal numbers against actual feed supplies should prevent the prevalent ruinous practice of overstocking that results in degradation of the rangelands, and a decline in reproduction, in growth and in physical condition of the herd. Prevention of such deterioration Is feasible; and it is sound economics to avoid the heavy expense involved in restoring grazing land productivity, and in rebuilding a decimated livestock herd after a severe drought strikes an overstocked range.

e. Providing feeds for the dry season. Supplemental feeds may be provided in several ways.

(1) Additional grazing lands are held in reserve without stocking, until such time as they are required to support the herd when normal grazing Lands are not sufficient.

(2) Feeds maybe grown and stored as hay or silage, on lands not included in the grazing areas. These can be used for breeding herd and young stock in periods of feed shortage.

(3) Crop products (stalks, vines, straw, screenings) may be saved and fed.

2. Providing mineral supplements to native forage.

Native forages are very often deficient in the essential minerals required by livestock for normal reproduction and growth. The improvement in overall performance of livestock herds is frequently quite outstanding when mineral supplements are fed. Thus, on the Llanos of eastern Colombia, the following mineral mixture has been proposed:



Percent by Weight



47 percent

blended mixture

Dicalcium phosphate, or bone meal

47 percent


Minor element mixture

6 percent


100 percent

The minor element mix contained the following: copper sulfate - 1.95%, iron sulfate - 5.00%, zinc oxide - 1.24%, magnesium sulfate - 3.09%, cobalt sulfate - 0.20%, potassium iodide - 0.07%, and ground cereal grains (to provide volume) - 88.45%.

The mineral mix was offered to stock at a considerable distance from the watering point, to avoid abnormal consumption in harmful amounts.

This Colombia mixture was a general purpose mixture formulated without specific information as to which trace elements might be seriously deficient. However, it may be assumed that phosphate is widely deficient in forage on grasslands of the semi-desert and subhumid regions. Dicalcium phosphate was used as a source of phosphate since bone meal was not available.

3. Rotation grazing to permit forage growth periods for natural restoration of vegetative cover, on a regular sequence.

When specific herdsmen are assigned well-defined grassland areas for their sole use, then it becomes feasible to establish a pattern of rotating the grazing herd over the available areas. By dividing the total areas into four or more sectors, the livestock herd maybe grazed for a few weeks on each sector in rotation. This provides every sector with a rest period for regrowth. If the season when rains occur, for example, is four months, the grazing herd should not be kept on any single sector for more than one month. The concept is to control grazing pressure so that all sectors are used about equally during the full grazing season.

It is highly desirable to select a different sector each year, for protection from grazing throughout the entire growing season so that natural seed production and seedling establishment can occur. It is desirable that each sector be protected in this manner for natural rejuvenation about once every three to five years. Experience on several continents has shown that forage production and livestock carrying capacity can be markedly increased by this practice.

4. Prohibit uncontrolled burning of all grassland, and invoke other methods of controlling undesired vegetation.

a. The motive for uncontrolled burning will largely be removed when management practices increase feed supply, and the stocking rate is adjusted to current feed supplies. Providing the necessary mineral supplement also is helpful.

b. Any burning to reduce invasions of the rangeland by woody shrubs and scrub trees, as well as reduction of other useless vegetation, should be done under carefully controlled conditions as noted in section III.7. Controlled burning also is a useful practice in preparation for introduction of promising new grasses and forage legumes.

c. Other methods of reducing the abundance of undesired vegetation may include tractor bulldozing or root plowing, hand grubbing of sparse stands of invading species, and the application of herbicide chemicals by ground applicators or by aerial application. Each of these methods is costly and should be undertaken only under recommendation by qualified specialists, and with close supervision by a qualified expert.

d. Before undertaking costly control methods, it would be prudent to make limited field trials of the proposed practices and materials, to determine their effectiveness as well as costs. It is clear that any costly practices should be limited to land areas having favorable soil conditions for growth of forage grasses and legumes. The benefits to be derived from controlled grazing to limit invasions of useless vegetation may be evaluated at low cost, and more expensive methods should be undertaken only as a supplement to controlled grazing.

e. Browse forage plants. It must not be assumed that palatable nutritious forage consists solely of grasses and herbaceous legumes, particularly in regions of limited rainfall. Browse plants include a wide variety of low-growing species with woody main stems, but which have palatable leaves and finer stem branches. Cattle make little use of such browse, but sheep, goats and camels may subsist quite well on palatable browse alone. There are marked differences between browse species, and the management practices should be designed to foster the better species.

Browse is important in desert ranges for feed production on land areas in runoff channels that are normally dry, but contain waterborne sediments (sand and silt). Where these alluvial sediments have appreciable depth, they act as reservoirs for runoff water, and browse plants make intermittent growth throughout the year, drawing on water stored in these sediments from occasional rains.

It is obvious that useful browse plants should not be regarded as undesirable woody vegetation in situations where grasses and forage legumes are not well adapted. Browse plants are usually native species, but there may be substantial opportunities for introducing superior species from other continents or regions, such as mesquite (Prosopis species) from North America, and reintroducing browse forage species that were once present but have been destroyed by overgrazing.

5. Adoption of management practices to protect against wind and water erosion, and to improve water conservation in regions of limited rainfall.

a. A comparatively dense cover of grasses and forage legumes on the land provides the best protection known against soil erosion from rainfall runoff, and against wind erosion. A around cover of grasses and legumes, also is the most effective method yet found for increasing infiltration of rains into the ground surface, and of holding it in the soil profile for use by plants for as long as it lasts. Further, water losses from the soil by direct evaporation, and by transpiration from leaves of plants is reduced by a grass-legumes cover on the soil. In general, the most effective use of water stored in the soil profile for production of usable for ace for livestock is that provided by a strong growth of forage grasses and legumes composed of species that are adapted to local climate and soil. Such plant cover is more efficient in use of water to grow forage than is true of brush and scrub trees. Where forage grasses and legumes are not adapted and do not survive in semi-desert regions, the browse plants may constitute the most efficient species for livestock support (See item 4.e.).

From the foregoing, it is evident that maintenance of a strong grass-legume cover will result in the most efficient use of rainfall in semi-arid and subhumid regions. Where overgrazing and other harmful management practices have denuded the land, the re-establishment of a grass-legume cover on the land should result in retention and utilization of rainfall that currently runs off and is lost, and produce the growth of forage in greater abundance than now occurs. It must become clear to the herders who use the land, that it can be made much more productive by prudent management.

When this relationship has been demonstrated by practical field trials, the users may then be persuaded to avoid over-stocking and to practice rotation grazing so that all range areas are allowed periods of "resting" and re-growth. This means that the herdsmen must focus attention on the land and forage supply and the means for protecting and nurturing it. It should become clear that the success of livestock enterprises depends on both the protection of land and forage resources and on the welfare of his livestock. The outlook for successful livestock enterprises without stabilized supplies of feed is forbidding. For herders in semi-arid and subhumid regions, this basic dependence of livestock on feed supplies is emphasized with every recurring drought.

b. Waterspreading is often a useful practice in both subhumid and semi-arid regions, as a means of controlling rainfall runoff that would otherwise be lost. By this practice, runoff water is diverted from stream channels or drainage courses that are normally dry but have flowing water after rains occur. The water spreading may have two functions: (1) increasing forage production by spreading the water over nearby smooth sloping land so that it infiltrates and is stored in the soil profile, and (2) reducing gulling and downstream flooding. Rangeland flood waterspreading systems are constructed so that operation is automatic whenever storms result in flood flows. The gentle slopes into which directed water is led should have fairly permeable soil to depths of 30 cm. or greater. Grades of I to 2% are preferred, but grades of 5% may be used if the soil is highly permeable. The water spreading system must be constructed to fit the local terrain. The essential features are a diversion barrier or berm and a system of meandering channels and dikes to direct the flow gradually down slope with sufficiently slow flow to allow infiltration into the soil profile. Dikes and/or furrows are placed to facilitate spreading on the area selected. Design of the water spreading system is best prepared by an agricultural engineer, particularly where costs of construction will be substantial. However, simple but effective waterspreading systems are found in some primitive regions, that have long been used both for crop production on limited areas, and for forage production. On well-designed systems, increased forage production has varied from three- to ten-fold where several natural floodings occur yearly.

c. Terracing to retain water on the land is feasible under some conditions. As in the case of waterspreading, runoff water is intercepted in the stream-bed, and is directed to a series of terraces that are stair-stepped down the slope. Dikes at terrace borders direct the flow across the slope to the entrance of the next terrace, and thence from terrace to terrace down slope. The design of such a system calls for technical expertise, and is warranted only where both the rainfall pattern and the soil type are such that increased production will exceed the cost when prorated over a period of years. Well-established sod of forage grasses and legumes should require very little maintenance effort, when the system has been established. This may be an important means of providing supplemental feed for livestock, that is not available otherwise.

6. Introducing superior forage species on rangelands and other permanent grasslands to improve forage yields and nutritive values.

a. Adapted grasses and legumes for different rainfall zones.

The species of forage grasses and legumes now present in rangelands and other permanent grasslands are those native to the region, that have survived under conditions of overgrazing and competition with unpalatable and woody types of plants. Restoration of indigenous useful forages maybe fostered by better control of stocking rates, periodic resting of areas to permit natural seeding and seedling establishment; supplemented by positive methods of reducing undesired vegetation.

These methods, while useful, do not exploit the opportunities for introducing superior forage species from other regions with similar climates and soils, that have proven to have outstanding values under similar types of land use. The opportunity to establish productive forage legumes along with additional adapted forage grasses gives unique significance to the practice of introducing new species in rangelands and other permanent grasslands Perennial forage legumes have substantial potential for adding to the protein and mineral content of the forages, and also contribute strongly to residual soil nitrogen that stimulates grass growth. Field experience in various other tropical countries has demonstrated substantial improvements above native forage, by these means. The following superior forage grasses and legumes have promise for the tropics and subtropics: (See appendix tables for information on forage species.)


Common Name

Botanical Name

(1) For dry regions having 10 to 25 inches (250-625 mm.) yearly rainfall.

(a) Forage legumes

Dwarf koa

Desmanthus virgatus



Leucaena leucocephala



Medicago sativa



Stylosanthes guyanensis


Townsville Lucerne

Stylosanthes humilis

(b) Forage grasses

Birdwood grass

Cenchrus sitegerus


Buffel grass

Cenchrus ciliaris


Bluepanic grass

Panicum antidotale


Love grass, Weeping

Eragrostis curvula


Love grass, Lehmann

Eragrostis lehmannania


Makarikari grass

Panicum coloratum makarikariense


Yellow bluestem

Bothriocloa ischaemum

(2) For subhumid regions having 30 to 40 inches (750-1000 mm.) yearly rainfall.

(a) Forage legumes


Centrosema pubescens



Glycine wightii



Desmodium intortum



Lotononis bainesii


Phasey bean

Macroptilium lathyroides


Silverleaf desmodium

Desmodium uncinatum



Macroptilium atropurpureum



Stylosanthes guyanensis

(b) Forage grasses

Alabang grass

Dicanthium caricosum


Angelton grass

Dicanthium aristatum


Bermuda grass

Cynodon dactylon


Carib grass

Eriochloa polystachya


Dallis grass

Paspalum dilatatum


Guinea grass

Panicum maximum


Harding grass

Phalaris tuberosa stenoptera


Molasses grass

Melinis minutiflora


Pigeon grass

Setaria sphacelata


Plicatulum grass

Paspalum plicatulum


Rhodes grass

Chloris gyana


Scrobic grass

Paspalum commersonii

(3) For humid regions with 40 or more inches (1000 mm.) yearly rainfall.

(a) Forage legumes


Calopogonium mucunoides



Centrosema pubescens



Lablab purpureus


Silverleaf desmodium

Desmodium uncinatum



Macroptilium atropurpureum

(b) Forage grasses - Propagated by seed

Alabang grass

Dicanthium caricosum


Angleton press

Dicanthium aristatum


Bahia grass

Paspalum notatum


Carib grass

Eriochloa polystachya


Molasses grass

Melinis minutiflora

(c) Forage grasses - Propagated vegetatively

African star grass

Cynodon plectostachys


Cynodon hybrids

Cynodon spp. (Bermuda grass hybrids)


Elephant grass

Pennisetum purpureum


Imperial grass

Axonopus scoparius


Kikuyu grass

Pennisetum clandestinum


Palisade grass

Brachiaria brizantha


Pangola grass

Digitaria decumbens


Para grass

Brachiaria mutica


Signal grass

Brachiaria decumbens

7. Correcting mineral deficiencies in soils of rangelands and other permanent grasslands.

There are two points of view in dealing with soil nutrient deficiencies: (1) the deficiencies affecting plant growth, and (2) those that affect performance of livestock. The simple production of more forage is useful where its nutritive content meets animal needs. However, there is good evidence that some plants may make substantial growth as to dry matter, but of such low content of protein and essential minerals that the feed has limited nutritive value. This situation is widespread on both dry ranges and humid pasture

a. Low protein forage. Much standing dry forage on dry grazing lands is so low in protein content (6% or less) that the energy feed constituents cannot be utilized beyond the available protein, even though eaten and passed through the animals digestive tract. The fostering of forage legumes in grazing lands, where feasible, is the most efficient way of supplying the necessary nitrogen (made available through root nodules) for stimulating growth of associated grasses, as well as for meeting the protein needs of grazing livestock. The alternative to fostering growth of legumes in grazing lands is to provide supplemental protein concentrate feeds particularly to the breeding herd and young stock. Increasing legumes in the forage is the preferred method in most situations.

b. Mineral deficiencies in soils of rangelands in semi-arid and subhumid regions. Phosphorus is widely deficient in such soils, and consequently in the forages grown on them. This deficiency may be great enough to hamper growth of legumes, even though most tropical forage legumes have stronger "feeding power" for soil phosphorus than temperate zone forage legumes. The magnitude of the soil phosphorus deficiency should be evaluated when introduction of new legumes in grasslands is contemplated. It may be necessary to apply phosphate fertilizer in preparation for seeding such legumes. Wherever the phosphorus content of forage is deficient for livestock, it may be necessary to supply supplemental phosphorus in a mineral mix (with salt) as a positive measure. This can meet livestock needs, in an inexpensive way even though the need for phosphorus by legume forages is not met.

In humid regions deficiencies in soil calcium, magnesium, potassium and sulfur are often found, and these adversely affect growth of forage legumes, as well as the performance of grazing livestock. In general, soil amendments are needed to correct these deficiencies so that legumes can be grown successfully, and these will also more nearly meet nutritional needs of livestock grazing on such forage. Low grade forage (wiry grasses and weeds) will grown on soils deficient in these minerals, but nutritive values of such forage are insufficient to support breeding stock and young animals even when total feed volume appears adequate. Fortunately, for virtually all soils (except some sands) in the semiarid and subhumid regions, calcium, magnesium, potassium and sulfur are adequate for both forage plant growth and for grazing livestock.

Trace element deficiencies are not uncommon in tropical and subtropical soils, both in regions of limited rainfall, and in humid regions. These deficiencies may involve only one, or several "trace" elements. These elements are required in very small amounts by both plants and animals, which accounts for the term "trace" elements, The elements are boron, zinc, molybdenum, copper, manganese, and iron. To these, must be added cobalt which is a requirement for animals, but not for forage plants. The correction of these deficiencies for livestock is easily accomplished by including small amounts of all of them in a salt-mineral mixture. However, when these deficiencies affect plant production, it becomes highly desirable to identify the specific soil groups in which individual deficiencies occur, and to develop practices to correct them. An example is provided in Australia where a large region that was quite unproductive responded quickly to a few grams of molybdenum per hectare, to produce abundant growth of a nutritious forage legume.

The identification of trace element deficiencies and development of practical methods for their correction is closely tied-in to the establishment and growth of legumes. Forage legume species differ in their ability to extract trace elements from soils. At least one legume species is capable of extracting copper from a deficient soil, and will succeed when others fail.

Because the general knowledge on the occurrence of trace element deficiencies in soils of the tropics and subtropics is still fragmentary, it would be desirable to mark this as a fruitful area for investigation wherever Forage legumes are unthrifty. The differences between the capabilities of different legume forages to extract trace elements from the soil, also needs more study to enable better matching of legume with kinds of soils. Fortunately, when the nutritional needs of forage legumes have been met, the mineral needs of livestock feeding on them also will be less critical. The exception is cobalt which is uniquely required by livestock, and must be supplied whenever deficient.

8. Preparations for introducing superior Forage species in grazing lands.

The introduction of superior forage grasses and legumes that are adapted to specific ecological zones offers great promise, when accompanied by other improved management practices. The simple broadcasting of seed on unprepared land is not a dependable means of improving forage production. However, there have been notable successes in various regions when the situation is carefully surveyed and practical preparations are made.

a. Control of brush and trees.

Wherever the grazing lands (rangelands or other permanent grasslands) are overgrown with trees, brush and other unpalatable vegetation, the reduction of this growth is necessary to provide opportunity for new seedings to become established. Practical methods might consist of (1) controlled burning under favorable conditions just prior to the rainy season, (2) use of selective herbicides applied as sprays or granules at seasons when the offending species are vulnerable, and (3) hand or machine grubbing. Any taller growing undesirable species should be reduced, so that adequate sunlight will reach the forage seedlings, and to reduce water consumption by the useless species.

b. Mineral requirements of forage species.

The ability of the forage species being introduced, to meet their nutrient requirements from the soils present on areas to be seeded, should be considered. Particular attention must be given to the mineral needs of the seeded legumes. The legumes have more specific needs than the grasses, and the presence of legumes will provide nitrogen for the grasses, as well as increase the nutritive value of the forage. Some legume species are known to have strong "feeding power" for slowly available major nutrients (phosphate, calcium, magnesium potassium, sulfur), and for the "trace elements" (zinc, molybdenum, boron, copper, iron, manganese). Chemical testing of soils to detect any deficiencies is easily done, and such tests have already been made on some major soil groups. Since the application of fertilizers and soil amendments may be quite expensive, it is important to learn which soil nutrients are actually in deficient supply.

For many situations, the mineral nutrient needs of legumes seeded in grasslands may be satisfied by the convenient and inexpensive practice of "pelleting" the seed by adding small amounts of deficient mineral nutrients to an adhesive and mixing this with legume seed just before planting. Such pelleting is compatible with inoculation of seed with the specific strains of nodule-forming bacteria that are needed to make the legume plants independent of soil nitrogen supply.*

*For more complete details on pelleting legume seed, see section B-5 in Technical Bulletin No. 12, "The Contribution of Legumes to Continuously Productive Agricultural Systems for the Tropics and Subtropics," published Jan. 1975 by Office of Agriculture, Technical Assistance Bureau, Agency for International Development, Washington, 3. C. 20523.

On soils that may be markedly deficient in one or more mineral elements, such as often occurs in humid regions, it may be necessary and economically effective to broadcast the fertilizer and work it into the surface soil by some form of light tillage. For subhumid (savanna) and semi-arid or semi-desert regions, phosphate is the most commonly deficient element. Where surface tillage is impractical, broadcasting the fertilizer on the ashes of burned areas before the onset of seasonal rains, may prove sufficient to establish and maintain forage legumes. Because of the variability of soils and climatic conditions in different regions, there is need to test the applicability of the optional methods on test areas before undertaking larger scale operations.

c. Seeding practices.

(1) All legume seed should be inoculated with the appropriate strain of root-nodule bacteria, just before planting. Seed suppliers normally are prepared to supply bacterial cultures for the species of legume seed being sold, together with instructions for treating the seed. Treated legume seed should be planted promptly. Where burning has been done, planting in the fresh ashes may provide sufficient coverage if rains occur soon thereafter. In more humid regions, seeding should be accompanied by light tillage so that seed will be covered by the next rain.

(2) A legume-grass mixture of species with compatible growth habits, adapted to similar rainfall zones, should be formulated (see appendix tables), and seed supplies brought to hand. Planting time is exceedingly important. The most favorable time is just at the beginning of a season when rains normally occur, to foster prompt germination and rapid seedling establishment. Small seeded species require shallow planting. Larger seeded legume species require seed placement at 1 to 2 cm. depths to insure germination and seedling survival.

Since virtually all seeding of rangelands and other permanent grasslands in all soil and climatic zones involves non-arable lands, any tillage in conjunction with planting must be achieved through special means that are feasible under local conditions. Therefore, every effort should be made to take advantage of seedings made when moisture is adequate, on fresh ashes after burning, or any other means of placing seed so that germination and seedling establishment will be fostered. Legume seedlings are more sensitive than grasses to moisture deficiencies; and practices that insure legume establishment will almost surely be adequate for the grasses in the mixture. Should weather be unfavorable for the legumes, the grasses will probably survive.

d. Planting methods.

Broadcast seedings of small amounts of seed, such as 5 to 10 kg. per hectare, require special care. The first step is to mix the seed with a large volume of a carrier substance, up to 20 volumes of carrier to 1 volume of seed. The carrier may be fine-texture plant material such as rice bran, or finely ground meal of a grain. A third choice might be screened, moist, fine-textured soil. Sand is not desirable, for it is too heavy. The seed and carrier should be well mixed just before planting; mixing the seed for each hectare separately. Broadcasting the mixture by hand calls for careful manipulation, and there should be preliminary practice using the carrier material without seed. Practice a sweeping motion, using the thumb and fingers to release small portions of a handful on the outward sweep and a small portion on the return sweep. There are small "whirlwind-type" broadcasting machines that are hand operated, and capable of adjustment to release metered amounts of seed. These inexpensive machines give reasonably uniform distribution.

The intent is to establish substantial populations of the introduced species on the initial seeding. With careful management, these initial plants will seed and spread to thicken the cover of improved species in successive years.

9. Management of renovated grasslands.

There is no useful purpose in introducing superior forage species if the new plantings are not protected from overgrazing and other mismanagement that would decimate the new species. Since the total feed production and feed quality will be substantially improved on renovated grasslands, the herdsman does not suffer by providing adequate protection. The greater productivity should be evident in the first year, and improve much more in the following two years where successful introductions have been made. Some localized failures due to erratic rainfall or infertile soil areas may be expected, but these should not deter campaigns to introduce superior forage species.

The young growth made by introduced plants is highly palatable. All grazing of newly seeded areas should be prohibited until the new species have produced a crop of seed. Further protection need only be that provided by normal good management to maximize forage production on a continuing basis.


V. Measuring productivity of rangelands and other permanent grasslands.

1. Estimating forage production during season of active growth.

Estimates of the forage production capacity of grazing lands are essential to guide the most effective grazing practices. These estimates may be in terms of actual forage produced annually per unit of land area, corrected to the amount that can safely be removed by grazing without depressing vigor of the forage species in the following growing season. The percentage of total forage that may be removed by grazing varies some with species and with climatological zones. When estimates have been made of total usable forage per hectare, per year, it is then feasible to predict the number of animal units that may be supported by the forage producing areas available.

The basic principle is to never permit grazing to remove so much of the tops of desirable forage plants that there is impairment in plant food manufacture and storage. This storage is necessary to maintain vigor and regenerative capacity in both root systems and top growth. The leaf area and roots must be fully functional during the remainder of the growing season after grazing terminates. The amount of top growth that can be safely used by grazing probably should not exceed 1/2 to 2/3 of the total growth made during the growing season.

With estimates of available forage at hand, it becomes necessary to determine whether the grazing herds must be supported for the entire year, or whether some or all of the livestock can be moved to other feed sources for part of the year. Such planning has in view the sustained maintenance of all stock, without prolonged periods of starvation that are common in many regions. Seasonal deprivation severely depresses productivity of the livestock, and wastes much of the forage they have consumed during the useful grazing period. These losses and wastes should be avoided by advance planning and implementation.

2. Methods of estimating available feed supplies.

a. Sampling the standing forage plant growth

An initial step is to estimate the equivalent air-dry weight of the forage grasses and legumes that are present on available grazing lands. This may be done by sampling, using small measured strips, each being about 10 meters long and 0.5 meter wide (total area - 5 square meters). There should be at least 20 such strips randomly distributed over the range area so as to be representative of the grazing area. Twenty strips would amount to 100 square meters. For large range areas, the number of samples should be increased.

When the harvested forage on sample areas is air dry, determine the weight and express this in kilograms per hectare. Twenty samples is 1/100 of a hectare, and thus the total dry weight is multiplied by 100 to give an estimate of dry forage per hectare.

From the amount of air-dry forage required for meeting feed needs for animal support, it is then possible to determine the hectares of range land required per animal unit, to provide feed for 1 month, or 6 months, or a full year. This method may serve as the national basis for determining stocking rates of range land.

For example, if the forage yield from 20 representative samples totaled 1 kilogram, then each hectare should produce 500 kg of feed (on air-dry basis). Such a range area would require 4 hectares to produce enough feed to carry one bovine animal unit for 1 year, if this is the only feed available. Actually, many rangeland areas are less productive than this; and 15 to 20 hectares may be needed to support each bovine animal unit for a full year.

b. Supplemental feeds

In the event that supplemental feed may be provided in the dry season from crop by-products (stalks, vines, etc.), the yield of such feeds also should be estimated. Also, if standing forage on separate grazing lands will be available to carry ruminants through the dry season, such forage should be estimated, so that total forage supplies from all sources may be estimated for comparison with feed needs of all ruminants (cattle, sheep, goats) per year.

3. Predicting seasonal forage Production on the basis of rainfall.

In semi-desert and subhumid regions where total rainfall fluctuates substantially from year to year, it is useful to determine the average plant growth response to greater or less rainfall than normal. For this purpose, It is necessary to compile records of forage growth made with rainfall experienced in the local region. When the seasonal response of plant growth in proportion to the amount of rainfall has once been estimated in terms of kilograms of forage per hectare, for different amounts of cumulative rainfall, predictions are possible as to feed resources to be expected for the season at hand. Predictions, at the close of the rainy season, made for the ensuing months of the dry season, can be estimated in time to make the necessary plans for adjustments in livestock numbers to be supported, either by use of reserved grazing lands, or by use of supplemental harvested feeds, or by sale or movement of livestock before serious weight losses or declining well-being of the herds and flocks occur.


VI. Estimating Feed Requirements of Ruminant Livestock in Tropical and Sub-Tropical Regions.

Precise information is generally lacking for a specific region, but general criteria may be formulated from fragmentary data in a few instances, supplemented with more comprehensive evaluations from rangeland livestock in the dry temperate zone regions.

For convenience, guidelines as to nutrient requirements of ruminant livestock (particularly cattle, sheep and goats), may be expressed in daily and yearly feed requirements expressed in total dry weight of forages consumed, and in the animal needs for total digestible nutrients (TDN), and crude protein.

1. Feed requirements for cattle.

a. For mature cattle


Total Dry Matter

Total Digestible Nutrients (T.D.N.) Content pet.

Crude Protein Yearly kg.


Daily kg.

Yearly kg


Feed maintenance requirement for animals weighing 300 kg. (average)





b. For young cattle (1 to 3 years of age)

Reduce per animal feeds to 70% of mature animals, to support limited growth.

c. For lactating cows

Increase nutrient requirements above maintenance by 1/3 or more, depending on milk flow.

When feed allowances are deficient, for shorter or longer periods, Livestock will lose weight in proportion to the extent of nutrient deficiencies. Regaining lost weight can only occur when feed supplies are more abundant than minimum maintenance requirements.

2. Feed requirements for sheep and goats

It is generally assured that 5 sheep or 5 goats in tropical and sub-tropical regions have a feed equivalent to 1 fully grown bovine (beef) animal. Thus:


Total Dry Matter

Total Digestible Nutrients (T.D.N.) Content pet.

Crude Protein Yearly kg.


Daily kg.

Yearly kg


Maintenance requirement per sheep or goat





For growing lambs and kids (up to 1 year age); reduce per animal feeds to 70% of mature animals, to support growth.

For lactating females; increase feed supplies above maintenance by 1/3 or more, depending on milk flaw.

Under deficient feed regimes, milk flow is curtailed or stopped, and weight losses occur. Regaining weight losses is possible only when feed supplies are more than adequate for body maintenance.

Sheep and goats have an advantage over cattle, in their use of browse plants (shrubs, bushes and other non-herbaceous vegetation) that are generally not consumed by cattle. The leaves and small branches of browse plants are richer in total digestible nutrients and in protein than mature grasses. m us, seasonal deficiencies in total feed and digestible nutrients are less serious with sheep and goats than for cattle on dry range, because of these differences in grazing habits.

3. Feed values of edible forage plants.

Nutrient content (and feed value) of forage plants is determined by the content of digestible nutrients, by the protein component, and by the adequacy in supplies of essential mineral elements. Since mineral supplements may be provided separately from forages, it is convenient to use two principal factors in estimating feed value; total digestible nutrients (T.D.N.), and protein content.

In calculating available feed supplies for grazing livestock the following averages may be utilized in converting the yearly production of plant herbage into animal support.

Mature tropical grasses may be assumed to contain about 50% T.D.N., and 4.0 to 6.0 % crude protein.

Perennial range legumes may be assumed to contain about 60 % T.D.N., and 12 to 15% crude protein.

Browse plants generally are more nutritious than grasses, but less so than forage legumes. me forage supply on rangelands tends to be deficient In protein content in the long dry seasons that are typical of rangelands; as well as being chronically inadequate in total amount of edible forage.

4. Relative feed values of growing forage plants on rangeland and pastures, and of mature plants.

While the volume of forage per hectare is much smaller during the period of flush growth following the onset of rains, than is achieved at plant maturity, the nutritive value per kilogram of mature forage is much lower. When converted from fresh weight to the air dry basis, the relative nutritive values per kilo of dry weight may average as follows:


Air-Dry Averages

Type of Forage

Total Digestible Nutrients (T.D.N.)

Crude Protein

Rapidly growing immature forage



Mature forage plants


4.5-5.5 %

The immature nutritious forage permits good milk flow of lactating females, and growth of calves, lambs and kids. It also permits rapid recovery of weight losses of older animals that have survived the dry season when feed ratios were inadequate for sustained maintenance. However, the prudent herdsmen must recognize that-this favorable season will be followed by a very long dry period when no new plant growth is made; and survival, or economic animal production must depend on standing dry forage reserved for this season, or on crop byproducts, or on harvested and stored forages.

5. Feed value of crop byproducts.

In many regions, the by-products of local crop production serve as supplemental feeds for livestock during the dry season when little or no plant growth is being made by rangeland forage grasses, legumes or browse plants. The amount of crop by-products that may be available, and their nutrient content are important factors in livestock enterprises, whether utilized by the farmers for their own livestock, or made available to non-farming herdsmen

me following aspects of the nutritional value of representative types of crop products illustrated the significance of such feed types:

Type of Feed

Total Digestible Nutrients (T.D.N.)

Crude Protein Content

a. Stover (stalks & leaves) of millets, sorghum, and maize


3 to 5%

b. Straw of cereal grains (wheat, barley, rice, etc.)


3 to 5%

c. Vines of grain legumes (groundouts cowpeas, soy beans, etc.)


10 to 20%

d. Other crops: sugar cane tops & leaves



cottonseed hulls & stems



e. Grass hays (mature)


4 to 8%

Grass-legume hays


10 to 15%


6. Balancing livestock numbers against total yearly feed supplies.

Failure to provide adequate livestock feed throughout the entire year, gravely reduces the possible income from any livestock enterprise. Growth and weight gains cease when feed supply is inadequate; and weight losses are regained very slowly when feeds are again more adequate. Reproduction is seriously reduced or prevented by seasonal starvation. Lactating females (cows, goats or sheep) quickly cease milk flow under deficient feed supplies, with adverse effects on growth and survival of suckling young animals, causing deprivation of farmer and herder families that depend on milk as a food.

There is no relief from the evil effects of deficient feed for livestock, to be gained by increasing livestock members. me most appropriate management of livestock enterprises is to adjust the size of livestock herds to the animal numbers that can be adequately sustained with available feed on a 12-month basis. When this principle is recognized, suitable livestock enterprises may become a mayor factor in fulfilling family food needs, and in providing dependable net incomes for marketable production that is surplus to family needs.

The yearly supply of livestock feed should Include all available sources, including (a) grazing lands that are reserved for dry-season feed, (b) forages that have been harvested and stored during the plant growth season for feeding in dry seasons; (c) crop by-products that may be conserved and utilized in the dry-season, and (d) any local surplus feeds that may be purchased for feed supplements. Livestock production is most profitable when the number of animals to be fed is no greater than the feed supplies that are available. Various knowledgeable livestock experts have estimated that the potential for livestock profitability in the tropics and sub-tropics may be enormously increased by maintaining a balance between livestock numbers and available feeds. me choices of the manager include (1) greater efforts to increase feed supplies, or (2) disposal of excess animal units, to stay within the total feed potential. Profitability is not the result of total animal numbers, but of the performance of well-managed herds and flocks. Livestock offtake (live animals, meat and milk) often may be increased by 100% by application of known technology and practices that maximize use of natural resources to support livestock production.


VII. Conclusions

1. On the basis of experience in certain developed countries of the tropics and subtropics, there is justification for believing that very substantial increases in productivity of ruminant livestock is widely feasible, by application of known principles and practices in feed production, in livestock management, and in efficiency of marketing live animals or their products.

2. There appear to be important opportunities to improve the management of natural resources of land, climate and vegetation, when firm associations of lands with land users are arranged and legalized by government edicts. In regions where communal grazing of herds and flocks prevails, there should be an extension of responsibility for allocation of grazing rights by the village or tribal leaders, so that the livestock owners are entitled to prier and exclusive use of designated grazing lands. This would be similar to the allocations of croplands to families in village or tribal groups, which now is customary. In Moslem countries, there is ample precedent, stemming from the Koran, for communal control of grazing lands. With such control, the management and improvement of grazing lands become feasible, and profitable to the users.

3. The average feed requirements for growth and reproduction of different classes of livestock are rather well established. Also, methods for estimating the total forage produced on grazing lands have been established in some tropical and subtropical countries; and these are believed to be widely applicable. These criteria provide essential information needed for rational management decisions and practices that should result in significant increases in productivity of livestock enterprises to the benefit of the individual herders and farmers, as well as to the economic viability of the nations.

4. Specific programs for particular ecological zones and regions of individual countries will be necessary to more adequately exploit feasible opportunities for enhanced productivity of livestock. These are essential for more complete and adequate utilization of these often neglected lands and forage resources, and to the welfare of the people that depend on their herds and flocks for subsistence and for incomes. The basis for change lies in the existing lands, flocks, and people; and extension of appropriate technical knowledge is a prerogative of national governments.




Appendix no. 1: Perennial Forage Grasses for the Tropics and Subtropics

A. Species propagated by seed.

1. Alabang grass - Dicanthium caricosum

2. Angleton grass - Dicanthium aristatum

3. Bahia grass - Paspalum notatum

4. Bermuda grass - Cynodon dactylon

5. Birdwood grass - Cenchrus setigerus

6. Blue panic grass - Panicum antidotale

7. Buffel grass - Cenchrus ciliaris

8. Carib grass - Eriochloa polystachya

9. Dallis grass - Paspalum dilatatum

10. Green panic grass - Panicum maximum trichoglume

11. Guinea grass - Panicum maximum

12. Harding grass - Phalaris tuberosa, var. stenoptera

13. Love grass (weeping) - Eragrostis curvula

(a. Boehr lovegrass - Eragrostis chloromelas)

(b. Lehmann lovegrass - Eragrostis lehmanniana)

14. Makarikari grass - Panicum coloratum makarikariense

15. Molasses grass - Melinis minutiflora

16. Pigeon grass - Setaria sphacelata

17. Plicatulum grass - Paspalum plicatulum

18. Rhodes grass - Chloris gayana

19. Scrobic grass - Paspalum commersonii

20. Yellow bluestem - Bothriochloa ischaemum

B. Species propagated vegetatively*

* Usually propagated vegetatively from nurseries planted to seed.

21. African stargrass - Cynodon plectostachys

22. Cynodon Hybrids - Cynodon hybrids

23. Elephant grass (Napier grass) - Pennisetum purpureum

24. Imperial grass - Axonopus scoparius

25. Kikuyu grass - Pennisetum clandestinum

26. Palisade grass - Brachiaria brizantha

27. Pangola grass - Digitaria decumbens

28. Para grass - Brachiaria mutica

29. Signal grass - Brachiaria decumbens


Appendix no. 2: Seed Characteristics and Adaptive Features of Forage Grasses


Seed Quality Standards

Seed Size Thousands

Seeding Rates

Yr. Rainfall


Plant Species



per lb

per kg





to drought

to soil water logging

Alabang grass











Angleton grass











Bahia grass





4 to 6

4 to 7





Bermuda grass





6 to 8

7 to 9





Birdwood grass





½ to 2

½ to 2



very good


Blue panic grass





½ to 3

½ to 3



very good


Buffel grass





½ to 4

½ to 4



very good


Carib grass











Dallis grass





6 to 10

7 to 11





Green panic grass





½ to 6

½ to 7





Guinea grass





2 to 6

2 to 6





Harding grass





2 to 4

2 to 4





Love grass, weeping





½ to 1

½ to 1



very good


Love grass, Lehmann





½ to ½

½ to 1



very good


Makarikari grass





1½ to 3

1½ to 3



very good


Molasses grass





2 to 4

2 to 4





Pigeon grass





2 to 5

2 to 5





Plicatulum grass





2 to 4

2 to 4





Rhodes grass





½ to 6

½ to 6





Scrobic grass





2 to 5

2 to 5





Yellow bluestem





1 to 2

1 to 2






Appendix no. 3: Major Forage Legumes for the Tropics and Sub-Tropics

1. Calopo - Calopogonium mucunoides

2. Centro - Centrosema pubescens

3. Dwarf Koa - Desmanthus virgatus

4. Glycine - Glycine wightii (G. javanica)

5. Greenleaf desmodium - Desmodium intortum

6. Lablab - Lablab purpureus

7. Leucaena - Leucaena leucocephala

8. Lontononis - Lotononis baineseii

9. Lucerne - Medicago sativa

10. Phasey bean - Macroptilium lathyroides

11. Puero (kudzu) - Pueraria phaseoloides

12. Silverleaf desmodium - Desmodium uncinatum

13. Siratro - Macroptilium atropurpeum

14. Stylo - Stylosanthes guyanensis

15. Townsville lucerne - Stylosanthes humilis

The types of nodule-forming bacteria (Rhizobium species) on most of these species are genetically and physiologically different from those used most successfully on forage legume of temperate zones. Lucerne is an exception.

For a comprehensive list of named varieties of each species, see FAO publication, "Tropical Pastures: Grasses and Legumes." Rome 1971. These varieties (cultivars) often are ecotypes rather than true-breeding types, but have demonstrated adaptation to particular regions. Seed sources are listed.


Appendix no. 4: Seed Characteristics and Adaptive Features of Forage Legumes


Seed Quality Standards

Seed Size Thousands

Seeding Rates

Yr. Rainfall


Plant Species



per lb

per kg





to drought

to soil water logging

1. Calopo





1 to 3

1 to 3





2. Centro





1 to 6

1 to 6





3. Dwarf Koa











4. Greenleaf Desmodium





1 to 2

1 to 2





5. Glycine





2 to 5

2 to 5





6. Lablab




5 to 20

5 to 20





7. Leucaena





4 to 6

4 to 6





8. Lotononis





¼ to 1

¼ to 1





9. Lucerne





½ to 5

½ to 5





10. Phasey bean





1 to 3

1 to 3





11. Puero





1 to 3

1 to 3





12. Silverleaf Desmodium





1 to 3

1 to 3





13. Siratro





1 to 3

1 to 3





14. Stylo





2 to 5

2 to 5





15. Townsville lucerne





2 to 3

2 to 3






Appendix no. 5: "Sources of Seed of Tropical Legumes"

(Extracted from Appendix 4 of FAO book on Tropical Forage Legumes, by P.J. Skerman)

NOTE: Many of these seed sources also stock seed of Tropical & Sub-Tropical forage grasses.


1. Divisao de Botanica e Ecologia

Instituto de Investigacao Agronomica

CP 406, Nova Lisbon



2. Division de Exploracion e Introduccion de Plantas (INTA)

Ministero de Agricultura

Buenos Aires

3. Instituto Nacional de Tecnologia Agropecuaria

Rivadavia 1349

Buenos Aires

4. Instituto Agrotecnico

Misiones, M-A

Buenos Aires


5. CSIRO Division of Tropical Agronomy

Cunningham Laboratory

St. Lucia, Queensland 4067

6. Anderson's Seeds Ltd


Brisbane, Queensland

7. Australian Estates Co. Ltd.

106-108 Creek St.

Brisbane, Queensland

8. Arthur Yates & Co. Pty. Ltd.

P.O. Box 42

West End, Brisbane


9. A.W. Rasmussen Pty. Ltd.

Mackay, Queensland

10. Frank Sauer & Sons Pty. Ltd.

Tozer St.

Gympie, Queensland

11. Dalgety & New Zealand Loan

Eagle St, Brisbane


12. State Produce Agency

Roma St, Brisbane


13. J.H. Williams & Sons Pty. Ltd

Murwillumbah, New South Wales

14. Wright, Stephenson & Co.

330 T. Kilda Rd


15. E.J. Eggins Pty. Ltd.

Lismore, New South Wales

16. The Producer's Cooperative Distributing Society Limited

Cribb St.,

Milton, Queensland


17. Central Sugar Cane Breeding Station



18. Departamento de Producao Animal

Secretaria de Agricultura

Sao Paulo, S.P.

19. Estacao Experimantal de Forages

San Gabriel

Rio Grande do Soul

20. Instituto Pesquisas Experimentos

Agropecuario Centro-Soul

Seccao de Agrostologia

Caixa Postal 28, ZC-00

Rio de Janeiro

21. Instituto de Pesquisas IRI


Sao Paulo

22. Instituto de Zootecnia

Universidad de Ceara


23. Aracatuba

Casa da Agricultura

Sao Paulo


24. Agricultural Department


Sri Lanka

25. Anderson and Co.


26. H.D. Constantine and Sons

GPO Box 378


27. R.R. Johnson and Co.


28. Central Agricultural Research Institute




29. Centro Nacional de Investigaciones Agropecuarias "Diulio Ospina"


30. Abadia y Jimenez


31. Caja Agraria


32. Proacal

Palmira, Valle

33. Programa de Forrajes

Instituto Colombiano Agropecuario (ICA)



34. Estacion Experimental Los Diamantes

Ministerio de Agricultura


35. Granja Experimental El Alto

Ministerio de Agricultura

San Jose

36. Instituto Interamericano de Ciencias Agricolas (IICA)

Centro de Investigacion y Ensenanza Graduada


37. "El Semillero"

Luis Cruz B.

Aparatado 783

San Jose


38. Estacion Experimental de Pastos y Forrajes "Indio Huatey"



39. Centre de recherches agronomiques IRAT

Niaouli (par Altogon)


40. Estacion Agricola Experimental "San Andres"

La Libertad


41. Director of Agriculture



42. Ets O. Genest et Cie 27 route de Venissieux Lyon 8e


43. Botanical Department University of Ghana Lagos

44. Council for Scientific and Industrial Research P.O. Box 3785 Kumasi

45. Faculty of Agriculture UST Kumasi

46. Ministry of Food & Agriculture Accra

47. Plant Introduction & Exploration Crop Research Institute Ghana Academy of Science Burso


48. Institut national de la recherche agronomique Domaine Ductas Petit Bourg


1 49. Buenavista Experimental Station Esquirdila


50. Central Agricultural Station Department of Agriculture Georgetown

51. Botanic Gardens P.O. Box 256 Georgetown 7A


52. Departement de l'agriculture des ressources naturelles et du developpement rural Damien, Port-au-Prince


53. Department of Agriculture and Forestry

North Kowloon


54. Agricultural College


55. Agricultural Research Institute

Coimbatore 3

56. Agricultural Research Institute

Chotagnapar, Ranchi


57. Agricultural Research Service

Tridoanum, South Arcot

58. BAI


59. Deochanda Experiment Station


60. Division of Botany

Indian Agricultural Research Institute

New Delhi

61. Central Arid Zone Research Institute


62. Economic Botanist

Institute for Agricultural Research


63. Indian Veterinary Research Institute


64. Government Economic Botanist

Kanpur, Uttar Pradesh

65. National Seed Corporation Ltd.

F. 44 South Extension Park

King Road, New Delhi, 3

66. Madras Agriculture Department


67. Pratap Nursery Seed Stores

P.O Premnagar

Dehra Dun 6


68. Institute for Agricultural Research



69. Plant Introduction Service

The Volcani Institute of Agricultural Research

P.O. Box 6, Beit Dagan

70. Hazera Seed Co.

P.O. Box 1565



71. Federazione Italiana dei Consorzi Agrari

Via Curtatone 3



72. Directeur des recherches

Office de la recherche scientifique d’Outre-Mer

BP Adropodoume


73. Institut d'enseignement et de recherches tropicales



74. Experiment Station

Grove Place


75. East African Agriculture & Forestry Organization

P.O. Box 34148


76. Kirchhoff's East Africa Ltd.

Box 30472


77. Kenya Seed Company

P.O. Box 553


78. Kenya Farmers' Association

P.O. Box 35


79. Mackenzie Dalgety Ltd

P.O. Box 30345


80. Katumani Agricultural Research Station

P.O. Box 340


81. Pasture Research Unit

National Agricultural Research Station

P.O. Box 450


82. Research Station



83. Station agronomique du Lac Alotra

IRAT, Lac Alotra


84. Federal Experiment Station


85. Pusat Penyelidikan Getan Tanan Malaya

(Rubber Research Institute of Malaya)

Petit Surat 150

Kuala Lumpur

86. Department of Agriculture

Kuala Lumpur


87. Agricultural Research Centre

P.O. Box 215


88. Chitedze Agricultural Research Station

P.O. Box 158


89. Makanga Experiment Station

P.O. Box 20



90. Department of Agriculture



91. Campo Experimental


Vera Cruz

92. Instituto Nacional de Investigacion Agricola

Mexico City


93. Institute for Agricultural Research

Ahmadu Bello University

P.O. Box 116, Samaru

Sheka Baria

94. Regional Research Station



95. West African Cocoa Research Institute



96. Agricultural College


97. Ayub Agricultural Research Institute


98. Department of Agriculture

Bangladesh, Dacca

99. Plant Introduction Officer



100. Punjab Agricultural College


101. Tandojam Agricultural College



102. John Fraser

Edif. CIA Panamena de eguros 3er. piso

Calle Richardo Arias

Apartado 4546

Panama 5


103. Director of Agriculture

Department of Agriculture

Port Moresby

104. Highlands Agricultural Experiment Station


105. Lowlands Agricultural Experiment Station

Keravat, Rabaul

New Britain

106. Plant Introduction and Quarantine Station

Laloki, Port Moresby


107. Instituto Agronomico Nacional



108. Universidad Agraria La Molina



109. Rio Piedras Estacion Experimental



110. Bureau of Plant Industry

Dept. of Agriculture & National Research


111. Bureau of Soils


112. College of Agriculture

University of Philippines


113. Economic Garden

Los Banos

114. Lamao Experiment Station

Lamao, Limay

115. National Forage Park

Rosario, La Union


116. Department of Agriculture

Soil Conservation Service

Kasama, Southern Province

117. Dept. of Research & Specialist Services

Salisbury Research Station

Causeway, Salisbury

118. Gatooma Research Station

P.O. Box 396, Gatooma

119. Grassland Research Station

P.B. 701, Marandellas

120. Institute SAR


BP 167, Butare

121. Matopos Research Station

PB 19, Bulawayo


122. Centre IRHO


123. Department of Botany

Universite de Dakar


124. Institut de recherches agricoles et de cultures vivrieres


125. Laboratoire national d'elevage et des recherches veterinaires

Dakar Hann


126. Fourah Bay College

University of Sierra Leone

Mt. Aureol, Freetown


127. Hooglant & Co.

P.O. Box 245



128. Division of Plant and Seed Control

Dept. of Agricultural Technical Service

P.B. 179, Pretoria

129. Division of Crops and Pastures

Department of Agriculture


130. Gunson Seeds, South Africa (Pty,) Ltd.

P.O. Box 9861


131. Prinshof Experimental Station


132. Rietondale Grass Station


133. ASA Seeds (Pty) Ltd.

317-319 Main Reef Road


134. Asgrow S.A. (Pty) Ltd

P.O. Box 2054


135. Bechuanaland Malt and Milling Co. (Pty) Ltd.

162 Vryburg

136. Cyclops Seed (Pty) Ltd.

Box 784


137. Delmas Koop Bpk.

P.O. Box 21


138. Directo Produce & Seed Supplies (Pty) Ltd.

6 Pim St.

Newtown, Johannesburg

139. Distin Sagseeds (Pty) Ltd

104 Brae

Newtown, St. Johannesburg

140. Eloff C. Mandla (Pty) Ltd

108 Brae St.

Newtown, Johannesburg

141. A. Ford & Company (Pty) Ltd

P.O. Box 5701


142. Gouws & Gouws (Pty) Ltd

10 Jeppe St.

Newton, Johannesburg

143. S. Jaffe & Co. (Pty) Ltd.

65 Pretorious Street


144. Johs Levy

P.O. Box 120


145. Kaha & Kahn (Pty) Ltd.

46 Pim Street

Newton, Johannesburg

146. Kingsbury & Co. (Pty) Ltd

42 Pim Street

Newton, Johannesburg

147. Lydenburg Voorspoed Koop

P.O. Box 17


148. Magaliesberse Graankoop (Ltd)

P.O. Box 61


149. Marino Koop (Ltd)

P.O. Box 48


150. Maurice Flior & Co. (Pty) Ltd

Box 7176


151. C. May and Co. (Pty) Ltd.

Box 4037


152. Noord Transvaalse Koop (Ltd)

P.O. Box 29


13. Noord-Westelike Koop Landbou Mpy. Bpk.

P.O. Box 107


154. Potgietersrusse Tabakkoop Bpk.

P.O. Box 2


155. S.A. Seed Exchange (Coop.) Ltd.

P.O. Box 1781


156. Schmidt & Co. (Pty) Ltd

P.O. Box 9809


157. Sentraal Westlike Koop Mpy. Bpk.

P.O. Box 98


158. Suid-Westelike Transvaalse Landbou Koop

P.O. Box 5


159. Vaalharts Landbou Koop Bpk.

P.O. Box 4


160. Voorspoed Saadhandelaars (Pty) Ltd.

151 Brae Street

Newton, Johannesburg

161. F.R. Waring (Pty) Ltd

Box 2090


162. West Rand Central Produce & Agric. Store (Pty) Ltd.

P.O. Box 414



163. Agricultural Research Div.


164. Kenana Research Station


165. Range & Pasture Research Dept.

Ministry of Agriculture



166. Lanboouw Proefst.



167. Veld & Pasture Officer

Agricultural Research Station

P.O. Box 4, Malkerns


168. Agricultural Officer

Central Research Station

Ilonga, Kilosa

169. Coast Experiment Station


170. Pasture Research Station


171. Senior Research Officer

Coffee Research Station


172. South Regional Research Centre


173. Sisal Research Station


174. Western Research Centre



175. Department of Agriculture

Srisomrong Street


176. Department of Botany

Kasetsart University


177. Pakchong Forage Crops Station


178. Rubber Research Institute



179. Department of Agronomy

University of West Indies

St. Augustine


180. Cotton Research Station


181. Kawanda Experiment Station


Bugande District

182. Makerere University College

P.O. Box 7062


183. Serere Experiment Station

P.O. Soroti



184. IRAT

P.O. Box 596

Saria par Ouagadougou


185. Jardin Botanico




Segrest Feed and Seed Co.

P.O. Box 338



Advance Seed Co.

P.O. Box 6157



F.M.C. Niagara Seeds

Box 3091



Everglades Branch Station

Fort Lauderdale

190. Florida Foundation Seed Producers Inc.

Florida Agricultural Experiment Stations

Gainesville, Florida

191. Indian River Research Station

Fort Pierce


192. Georgia Experiment Station



193. Agronomy and Soil Department

University of Hawaii


194. Hawaii Agricultural Experiment Station



195. College of Tropical Agriculture

University of Hawaii



196. Dekalb Seed Inc.

Sycamore Road


197. P.A.G. Division

W.R. Grace and Co.

Box 470, Aurora


198. Pioneer Hybrid Corn Co.

1206 Mulberry Street

Des Moines


199. Frontier Hybrids Inc.

Scott City


200. Kalmbach-Buckett Co. Inc.



201. USDA Crop Research Branch

Plant Introduction, Beltsville


202. Rudy-Patrick Seed Co.

1212 West 8th Street

Kansas City 1


203. McNair Seed Co.



204. Paymaster Seed Co.

Star Route


205. Delta Inc.;


206. Taylor Evans Seed Co.

P.O. Box 480


207. Lindsey Seed Co.



208. Kingshill St. Croix

Agricultural Institute


209. Centro de Investigaciones Agronomicas


210. Servicio de Pastos y Forrajes

Facultad de Agronomia

Universidad del Zulia



211. Centre de recherche agronomique

Yangambi, Kinshasa

212. Jardin d'essais d'eala

BP 278, Mondaka


213. Station de recherches agronomiques



214. Msekara Regional Experiment Station

Fort Jameson

215. Mount Makulu Research Station

P.O. Box 7, Chilanga

216. Pasture Research Officer

Nisamfu Research Station

P.O. Box 55



Appendix no. 6: Sources of Rhizobium Cultures for Tropical Legumes

This list of names and addresses of organizations handling inoculants is necessarily incomplete but supplies information as to where inoculants can be obtained. Sources of inoculants for temperate legumes can be obtained from Dr. E. Hamatova, Department of Microbiology, Central Research Institute of Plant Production, Prague, Ruzyne, or Professor O.N. Allen, Department of Bacteriology, University of Wisconsin, Madison, Wisconsin 53706, U.S.A.

As more effective strains are developed, the present ones will be superseded and an up-to-date list is published from time to time in the Rhizobium Newsletter edited by Professor J.M. Vincent, Department of Microbiology, School of Biological Sciences, University of New South Wales, P.O. Box l, Kensington, New South Wales, Australia. It is available to persons interested in using it, for a small charge.


Dr. Enrique Schiel

Instituto de Microbiologia e Industrias Agropecuarias

Villa Udaondo, Castelar

F.C.N.D.F.S., Prov. De Buenos Aires, Argentina

(on agar)

Roberto E. Halbinger

Quimica Industrial y Comercial

Tecnologia en Industrias Agricola

H. Yrigoyen 571, Buenos Aires

Jose P. Radibak

Tamborini 3094

Buenos Aires, Argentina

Grace & Crawford Keen y Cia

San Martin 232

Buenos Aires,


Florida 622

Buenos Aires,

Instituto Agrotecnico

Avenida Las Heras 727,


Prov. del Chaco, Argentina

(on agar)


Dr. R.A. Date

CSIRO Division of Tropical Pastures

St. Lucia, Oueenland 4067

Tropical Inoculants

1 Kneale St.

Holland Park


(inoculants sold under the trade name of TROPICAL INOCULANTS)

Dr. R. Roughley

Biological and Chemical Research Institute

PMB 10, Tydalmere

New South Wales, 2116

Professor J.M. Vincent

School of Microbiology

University of New South Wales

P.O. Box 1, Kensington

New South Wales, 2033

D.J. Pulsford

Agricultural Laboratories

P.O. Box 8

Carlington St., Regent's Park New South Wales, 2143

(inoculants sold under the trade name of NOCULAID)

R. Daniels

Root Nodules Pty. Ltd

49 Chandos St., St. Leonards New South Wales, 2065

(inoculants sold under the trade name of NITROGERM)

The Head of the Department of Soil Service and Plant Nutrition

Institute of Agriculture

University of Western Australia

Nedlands, Western Australia, 6009

The Director

Dept. of Agriculture, Stock and Fisheries


Papua, New Guinea


J.R. Jardim Freire, Ing. Agr.

Seccion de Microbiologia Agricola

Secretaria de Agricultura,

Porto Alegre

Rio Grande del Sur

Instituto de Biologia y Pesquisas Tecnologicas

Casilla Postal 357

Curitiba, Parana

Laboratorio Leivas Leite S.A.

P.O. Box 91, Pelotas

Rio Grande del Sur


Luis S. Longeri

Universidad de Concepcion, Dep. Microbiologia

Casilla 272, Concepcion

(inoculants distributed under the trade name of NITROFIX)


The Kenya Seed Company

P.O. Box 553

Kitale, Kenya

(sole distributor of rhizobia for east Africa)


Dr. C.C. Casas

Escuela Nacional de Ciencias Biologicas

IPN Apartado Postal 42-186

Mexico, D.F.

(inoculants distributed under the trade names of NITRAGIN and PAGADOR)


Ing. Agric. Rodolfo Vargas

Estacion Experimental Agricola de La Molina

Apartado 2791


American inoculants distributed as:

NODOGEN - Nodogen Laboratories,

Princeton, Illinois, United States

NITRAGIN - The Nitragin Co. Inc.,

Milwaukee, Wisconsin 53209,

United States


Dr. B.W. Strydom

Dept. of Agricultural Technical Services

Plant Protection Research Institute

Agriculture Building

Beatrix St., Private Bag 134


S.A. Legume Inoculant Company (Pty) Ltd.

P.O. Box 248



Dr. Carlos Batthyany

Laboratorio de Microbiologia de Suelo del M.G.A.

Ciudadela 1471


Laboratorios Dispert S.A.

Avenida Garibaldi 2797


(inoculants distributed under the trade name of NITRASOIL)

Esur Ltda.

Azara 3387


(inoculants distributed under the trade name of NITRUR)


Selected tropical-temperate inoculants

Plant Cultures

P.O. Box 284

Gainesville, Florida

Dr. U.M. Means

U S Soils Laboratory

Dept. of Agriculture

Beltsville, Maryland 20705

The Nitragin Company

3101 W. Custer Avenue

Station F. P.O. Box J

Milwaukee 9, Wisconsin

(inoculants sold under the trade name of NITRAGIN)


Appendix no. 7: Additional Publications Dealing with Livestock Production and Feed Supplies

issued by:





Technical Bulletin Series

No. 1 Improved forages for tropical and sub-tropical regions, as feed for livestock. 1971.

No. 2 Guidelines for improving livestock production on rangelands. 1971.

No. 12 The e contribution of legumes to continuously productive agricultural systems for the tropics and sub-tropics. 1975.

No. 13 Seeded forages for grazing and for harvested feeds in the tropics and sub-tropics. 1975.

No. 14 Characteristics of economically important food and forage legumes, and forage grasses for the tropics and sub-tropics. 1975.

No. 19 Combined crop/livestock farming systems for developing countries of the tropics and sub-tropics. 1976.

No. 20 Providing forages for ruminant livestock during dry seasons in the tropics and sub-tropics. 1977.