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close this book Grazing and rangeland development for livestock production
close this folder Combined Crop/Livestock Farming Systems For Developing Countries of the Tropics and Sub-Tropics; Technical Series Bulletin No. 19
close this folder III. Facilitating the successful addition of livestock enterprises to crop farming systems.
View the document A. Information on costs and benefits.
View the document B. Providing livestock feed during dry seasons.
View the document C. Technical assistance on effective use of feedstuffs.
View the document D. Developing milk processing to greatly enlarge markets for local milk producers.
View the document E. Effective livestock husbandry.
View the document F Perennial forage grasses and legumes in crop rotations to support livestock enterprises.
View the document G. Suitable credit for animal enterprises.
View the document H. Providing animal health care.
View the document I. Cautions on use of communal or open grazing lands.

F Perennial forage grasses and legumes in crop rotations to support livestock enterprises.

The advantage of including forage legumes and grasses in crop rotations to improve soil productivity have been stated in a foregoing section. They are usually equally valuable in improving feed supplies for ruminant livestock enterprises. These plantings should persist for at least two years to produce the desired improvement in soil conditions. (see Table 5, pp. 19&20)

The attached list of forage grasses and legumes is preliminary in nature; based on the limited printed information available. As additional experience is acquired on performance of species grown in mixtures and as components of farm rotations, the number of suitable grasses and legumes that perform well without becoming weed hazards should be enlarged. For example, Brachiara decumbens might be added as a useful grass, and Desmodium distortum as a forage legume. Some species may be useful in certain regions and not in others. The ultimate potential for perennial forages suited for inclusion in crop rotations will doubtless be greatly enlarged by research and experience.

It should be noted that the species shown in table 5 have been selected to avoid any possibility that they might become weeds. This is important so that subsequent crops will not have additional weed problems. An additional factor in effective use is to graze the crop or harvest it whenever the legume or grass begins to flower or produce heads. During the growing seasons, the forage should not be allowed to produce seed, since the digestibility of the feed declines rapidly after heading or blooming. However, forage will mature when left standing to be used as feed in the dry season.

Cultural practices for establishing perennial forage plantings should be adjusted so that seeding occurs at the beginning of the rainy season. This insures rapid seedling establishment and growth.

Seed mixtures should contain 2 species each of perennial grasses and legumes. The total amount of seed will range from 5 to 10 lbs. per acre (5 to 10 kg per hectare), with about equal weights of grasses and legume seed. Lighter seedings rates are suitable for regions of lesser rainfall, and heavier rates for regions of more abundant rainfall.

Fertilizer. Limited amounts of nitrogen fertilizer (or animal manures) may sometimes stimulate seedling establishment, but no further nitrogen is needed after the legumes are well established. Phosphate fertilizers will benefit the legumes particularly, and should be incorporated in the soil during seed bed preparation. Other fertilizer needs may be determined by soil testing or actual field trials, as used on crops of the rotation.

TABLE 5 - Perennial Tropical Forage Grasses and Legumes, Suited for Use in Crop Rotation to Maintain Soil Productivity, and to Support Livestock Enterprises.

A. For regions with 10 inches or more annual rainfall (250 mm, or more)

1. Grasses

Birdwood grass - Cenchrus setigerus

Buffel grass (short variety) - Cenchrus ciliaris

Love grass - Eragrostis curvula

B. For regions with 20 inches or more animal rainfall (500 mm or more)

1. Grasses (including those in section A)

Blue Panic grass - Panicum antidotale

Makarikari grass - Panicum coloratum makarikariense

2. Legumes

Dwarf Koa - Desmanthus virgatus

Townsville Lucerne - Stylosanthes humilis (cool season rainfall only)

C. For regions with 30 inches or more annual rainfall (750 mm or more)

1. Grasses (including those in preceding sections)

Harding grass - Phalaris tuberosa stenoptera

Plicatulum grass - Paspalum plicatulum

2. Legumes (including those in preceding sections)

Leucaena - Leucaena leucocephala

Lucerne - Medicago sativa

Phasey bean - Phaseolus lathyroides

D. For regions with 35 inches or more annual rainfall (845 mm or more)

1. Grasses (including those in preceding sections)

Pigeon grass - Setaria sphacelata

Scrobic grass - Paspalum commersoni

2. Legumes (including those in preceding sections) Stylosanthes - Stylosanthes guyanensis

E. For regions with 40 inches or more annual rainfall (1000 mm or more)

1. Grasses (Including those in preceding sections)

Alabang grass - Dicanthium caricosum

Molasses grass - Melinis minutiflora

2. Legumes (including those in preceding sections)

Lablab - Dolichos lablab

Silverleaf desmodium Desmodium uncinatum

Table No. 6

Perennial tropical forage grasses and legumes suitable for use in crop rotations to maintain soil productivity, and to support livestock enterprises

 

Minimum
Seed Quality Standards

Seed Size Thousands

Seeding Rates

Minimum
Yr. Rainfall

Tolerance

Plant Species

Germi-nation
%

Purity
%

per lb

per kg

Acre

Ha

In.

mm

to drought

to soil water logging

A. Regions with 10 inches or more annual rainfall

Grasses

Bird-wood grass

30%

80%

80

175

½-2

½-2

10

250

very good

poor

Buffel grass

30

80

200

440

½-4

½-4

10

250

very good

poor

Love grass

80

90

1500

3300

½-1

½-1

10

250

good

poor

B. Regions with 20 inches or more annual rainfall

Grasses (including those in section A)

Blue panic grass

50

80

650

1430

½-3

½-3

20

500

very good

fair

Makarikari grass

30

90

725

1600

1½-3

1½-3

20

500

good

good

Legumes

                   

Dwarf koa

80

70

20

40

2

2

20

500

good

poor

Townsville lucerne

90

40

200

440

2-3

2-3

20

500

good

poor

(cool season rainfall only)

C. Regions with 30 inches or more annual rainfall

Grasses (including those in preceding sections)

Harding grass

60

90

300

660

2-4

2-4

30

750

good

good

Plicatulum grass

30

55

385

850

2-4

2-4

30

750

good

good

Legumes (including those in receding sections)

Leucaena

90

50

12

26

4-6

4-6

30

750

good

good

Lucerne

90

80

200

440

½-5

½-5

30

750

good

poor

Phaseybean

90

70

56

125

1-3

1-3

30

750

good

good

D. Regions with 35 inches or more annual rainfall

Grasses (including those in preceding sections)

Pigeon grass

30

90

600

660

2-5

2-5

35

875

fair

good

Scrobic grass

30

95

170

375

2-5

2-5

35

875

fair

good

Legumes (including those in preceding sections)

Stylosanthes

90

40

160

350

2-5

2-5

35

875

good

fair

E. Regions with 40 inches or more annual rainfall

Grasses (including those in preceding sections)

Alabang grass

34

23

-

-

18

20

40

1000

fair

fair

Molasses grass

30

60

6000

13000

2-4

2-4

40

1000

fair

fair

Legumes (including those in preceding sections)

Lablab

90

50

2½-

5

5-20

5-20

40

1000

good

fair

Silverleaf desmodium

90

50

95

210

1-3

1-3

40

1000

fair

fair

For further information on these forage specie , see Technical Series Bulletin No. 14, "Characteristics of Economically Important Food and Forage Legumes and Forage Grasses for the Tropics and Sub-Tropics", published by TA/AGR, U.S. Agency for International Development, Washington,

D.C., 1975.

Since a single fertilization is made at planning time to support the forage crop for at least 2 years, the amount of fertilizer should be increased proportionately, particularly the phosphate fertilizer.

Inoculation of legume seed just before planting is highly essential. The legume inoculants must be composed of strains of root nodule bacteria that are compatible with the legume species being planted. The inoculation material is usually supplied as a black powdery material; and the rates of use are given on the container. Mixing is simple; the culture is sprinkled on slightly moistened seed, and well stirred so that every seed carries some of the inoculum. Treated seed should be planted promptly thereafter, and shallow tillage given to cover the seed lightly. The bacteria in the culture begin growth as the seed germinates, and will inoculate the legume roots at an early stage of growth.

Seed bed preparation should produce a well compacted pulverized soil surface, since the seeds are small and should not be planted too deeply. Light tillage after planting will provide sufficient coverage of seed.

Protect new plantings. The young plantings should normally be protected from all grazing or harvest until the grasses begin to produce heads or the legumes to produce flowers. After the first harvest, the fields may be grazed intermittently, or harvested whenever a new crop of grass heads or legume flowers occur. The greatest benefits to soil improvement, and the greatest yields of forage for livestock are achieved when regrowth is protected until blooming or heading occurs.

However, best performance takes place as to yields and forage quality when top growth is harvested promptly as these growth stages.

When forage plantings are grazed, it is important that the livestock be managed in a way that is compatible with good animal production, as well as fostering sustained forage plant vigor. Overgrazing and overstocking are self-defeating. These practices are unfortunately widespread, and they must be corrected by any feasible means because of adverse effects on productivity, and on profitability to the farmer. Desirable management practices for local conditions are simple and feasible, and these are easily transferable to producers.

It should be noted that this bulletin does not deal with production of other forages on arable lands, that may be periodically cut and fed green to livestock. There are many such feedstuffs, but they do not fall within the scope of mixtures of perennial forages grown in crop rotations to: (a) improve the long-term productivity of arable lands, and (b) to provide nutritious feed for ruminant livestock. Some examples of such feedstuffs would include elephant grass grown with abundant water and supplemental nitrogen fertilizer for harvest every 60 days, sugar cane harvested whenever height of 3 to 4 feet is reached, berseen (a cool season annual) grown with irrigation or adequate rainfall for harvest every 30 to 45 days, sorghum-sudan hybrids grown as warm season annuals with periodic harvests, and others that may have good regional performance.