|CERES No. 134 (FAO Ceres, 1992, 50 p.)|
Grassroots field work in Latin America
by Miguel A. Altieri
For most rural Latin Americans, the 1980s were an economic "lost decade", a period of crisis that imposed heavy social and environmental costs.
One of the few gains registered in this otherwise dark time may have been the delivery of a body blow to the credibility of many conventional, top-down agricultural strategies - and a corresponding rise of interest in what some call the "agro-ecological" approach. In country after country, farmers and rural villagers, in alliance with grassroots-oriented non-governmental organizations (NGOs), have been working out their own new, local cultivation and farming systems - and testing them successfully in the field. Though adequate methodologies for weighing the results are still lacking, these hundreds of individual efforts hold great promise for the development of more sustainable ways of growing food.
Before looking at some actual examples, which range from no-till farming on hillsides to the reconstruction of all-but-forgotten ancient Inca systems of high-altitude horticulture, let's put them in context:
Lessons from losses
The losses of the 1980s taught Latin Americans several lessons:
conventional, top-down development strategies are fundamentally limited in their ability
to promote equitable, sustainable development. Despite a succession of internationally
and state-sponsored development projects, poverty, food scarcity, malnutrition, poor
health and degradation of the environment are still common everywhere in the region;
agricultural modernization emphasizing high-input technologies, and proceeding without
effective land distribution, exacerbates environmental problems;
simultaneously, the failure of conventional development projects has legitimized the role
of NGOs, whose grassroots efforts directly target the poor and challenge top-down
food production requirements can no longer be considered apart from environmental
ones. Agricultural development cannot compromise the resource base.
Sustainability is emerging as a central development theme in the region, in government and international circles as well as among NGOs. The goal is to maintain agricultural productivity with minimal environmental impact, assuring adequate returns while providing for the social needs of the entire population. Unfortunately, there are no jiffy recipes for achieving sustainability, and both policy-makers and development workers seem caught up in a series of rhetorical arguments over such key questions as: should farm production for export or domestic use be stressed? Should efforts concentrate on boosting productivity on optimal or marginal lands? Should high- or low-input technologies be emphasized? Should high-yield or traditional varieties be planted? Should local farmers be included in research and development work, or not?
Dilemmas abound, while top-down projects sponsored by the state or international organizations often don't address pressing economic, environmental or regional production needs. or provide viable options for the mass of resource-poor peasants.
There are some 200 NGOs in the region, most of which have gone beyond the mere rhetoric of sustainability to concentrate on promoting technologies which are sensitive to the complexity of local farming systems. Many build on traditional farming knowledge, combining it with elements of modern agricultural science to boost production, while striving to achieve food security, biological stability, resource conservation and equity.
Of course, their efforts are not free of obstacles. Most NGOs are aware of their knowledge and technical gaps, and are interested in strengthening the technical capability of their personnel. While this want is being partly met by training and information exchange efforts coordinated by the Latin American Consortium on Agro-ecology and Development (GLADES), help is urgently needed.
The macro-economic conditions under which peasant production must operate also limit profitability at household level. NGOs must promote alternatives that are profitable, as well as ecologically sound, and the right socio-economic conditions are crucial for new strategies to be successfully repeated. The state's role is thus fundamental.
NGOs in the region have been actively trying out new farming strategies, based on local participation, skills and resources. Their approach gives unprecedented significance to local farmers' knowledge of their own areas' ecosystems - plants, soils and ecological processes - hence the term agro-ecology. The resulting agricultural approximation to the peasant production process is radically different from that of the Green Revolution or other high-input approaches (see Table). It also tends to be more socio-culturally acceptable, since it builds on local tradition. Techniques are ecologically sound because they don't radically modify or transform the peasant system, instead identifying traditional and/or new management elements that, once incorporated, lead to optimal production.
By emphasizing the use of locally-available resources, rather than expensive or hard-to-obtain imported inputs, these technologies are also more economically viable.
In practical terms, NGO programs emphasize six key points:
(1) Improving production of basic foods, including traditional food crops (Amaranthus, quinoa, lupine, etc.), and conservation of native crop germplasm.
(2) Recovering and re-evaluating peasants' knowledge and technologies.
(3) Promoting efficient use of local resources (land, labor, agricultural byproducts, etc.).
(4) Increasing crop and animal diversity in the form of polycultures, agroforestry systems, integrated crop/livestock systems, etc., to minimize risks.
(5) Improving the natural resource base through soil and water conservation and regeneration practices.
(6) Reducing the use of external chemical inputs, through developing, testing and implementing organic farming and other low-input techniques.
Despite insufficient and in some cases unreliable data, preliminary qualitative evaluations of some NGO programs show agro-ecological schemes have resulted in such tangible benefits for local populations as higher food production, regeneration and improved quality of natural resources, and higher use-efficiency of local resources. These successes are commendable, given the diverse socio-economic and biophysieal handicaps - from lack of access to land and low peasant family incomes to drought, frost and marginal soil - under which NGOs operate.
As already noted, appropriate means for evaluating the impact of such programs, and a satisfactory set of indicators to judge their viability, adaptability and durability, are in short supply. However, some progress has been made using two relatively new procedures: rapid rural appraisal (RRA) and natural resource accounting (NRA). RRA techniques emphasize the informal gathering and presentation of information, to foster a participatory process between local people and researchers. Technologies are evaluated through very general criteria, addressing environmental, economic and social concerns expressed by residents. NRA techniques incorporate environmental factors in conventional cost-benefit analyses, and can be used to measure the real profitability of alternative systems, including their effects on the natural resource base.
Despite the availability of these analytical tools - which may not be perfect but at least provide a starting point - and the obvious promise of the systems in question, little has been done by academic research institutions in the region to try to quantify the impacts of agro-ecological strategies.
The NGOs themselves, meanwhile, are action-, rather than research-oriented and must operate with minimal funds. Nevertheless, several have engaged in modest research efforts, yielding important information, as the following brief survey shows:
Conserving soil on slopes
A major challenge in Latin America is designing hillside cropping systems that maintain yields while reducing erosion. Several NGOs have taken on the challenge, and Loma Linda, in Honduras, has developed a simple, no-till system for steep slopes. Initially, weeds in a fallow area are simply cut with a machete or other tool, and no soil is removed. Using a hoe or small plow, small furrows are made every 50 to 60 centimetres, following the contour. Seeds and compost and/or chicken manure are placed in the furrow and covered with soil. As the crop grows, weeds are kept mowed to avoid excessive competition, with the cut weed biomass left between rows as a mulch cover and source of organic nutrients. Excellent yields can be obtained this way without using chemical fertilizers and - more importantly - without significant soil loss.
In a similar project in Guinope, Honduras, the private voluntary organization World Neighbors began a development and training program to control erosion and restore soil fertility. It introduced such soil conservation practices as drainage and contour ditches, grass barriers and rock walls, and emphasized such organic fertilization methods as using chicken manure and intercropping with leguminous plants. In the first year, yields tripled or quadrupled from 400 kilograms per hectare to 1 200 to 1 600 kilos. This jump in per-hectare grain production has assured the 1 200 families participating in the program ample grain supplies for the ensuing year. In the past five years, 40 other villages have requested training in the soil conservation practices.
Increased per-hectare productivity means most farmers are now farming less land than before, allowing more territory to grow back to pine forest or be used for planted pasture, fruit or coffee trees. The net result is that hundreds of hectares formerly used for erosive agriculture are now covered by trees, while production has not suffered.
In Peru, several NGOs as well as government agencies have programs to restore abandoned terraces and build new ones. In the Colca Valley of southern Peru, the Programa de Acondicionamiento Territorial y Vivienda Rural (PRAVTIR) sponsors terrace construction by offering peasant communities low-interest loans or seeds and other inputs to restore abandoned terraces, up to 30 ha at a time. The advantages of terraces are that they minimize crop loss risk in times of frost or drought, improve crop yields, reduce soil losses, and amplify cropping options because of the microclimatic and hydraulic advantages they provide. First year data from new bench terraces showed a 43 to 65 per cent increase in yield in potatoes, maize and barley, compared to yields grown on non-terraced slopes. A drawback of this technology is that it is labor-intensive. An estimated 2 000 worker-days would be needed to reconstruct one hectare in the Colca Valley region, although in other areas of Peru terrace reconstruction has proven less labor-intensive, requiring only 350 to 500 worker days/ha.
In the Central Cordillera of the Dominican Republic, most residents are resource-poor farmers devoted to subsistence agriculture, which combined with other social phenomena results in soil erosion. The short-fallow, shifting cultivation conuco itinerante cropping system dominates, but rarely permits forest regrowth. Rather, with land concentration and population pressure, it is converted to pasture, or simply becomes unproductive due to soil degradation and loss of fertility caused by the short fallow periods.
About 10 years ago, Plan Sierra, an ecodevelopment project, decided to break the link between rural poverty and environmental degradation. Its strategy involved developing less erosive production systems than the conucos used by local farmers. Controlling runoff would not only stop erosion, but could also make use of hydroelectric potential and make possible the irrigation of up to 50 000 ha of land in the downstream Cibao Valley.
The specific objectives were to allow farmers to make more efficient use of soil moisture and nutrients, crop and animal residues, natural vegetation and genetic diversity, as well as family labor, in order to satisfy their need for food, firewood, construction materials, medicinals and cash income. From a management viewpoint, the strategy consisted of a series of farming methods integrated in several ways:
soil conservation practices such as terracing, minimum tillage, alley cropping, use of
living barriers, mulch, etc.;
use of leguminous trees such as Gliricidia, Calliandra, Cajanus and Acacia spp., planted
in alleys, for nitrogen fixation, biomass production, green manure, forage production,
and sediment capture;
use of organic fertilizers based on optimal employment of plant and animal residues;
adequate combination and management of polycultures and/or rotations planted along
the contour and at optimal crop densities and planting dates;
conservation and storage of water through mulching and water harvest techniques.
Animals, crops, trees and shrubs are integrated, to produce multiple benefits, including soil protection, diversified food production, firewood, and improved soil fertility.
Since more than 2 000 farmers adopted at least some of the improved practices, an important task of Plan Sierra was to determine the erosion reduction potential of proposed systems. This was difficult because most methods of estimating erosion aren't applicable to farming systems managed by resource-poor farmers under marginal conditions. Given the project's lack of funds and research infrastructure, a simple method using measuring stakes had to be devised, for employment on both traditionally-managed and improved conucos.
Figure (a) depicts the cumulative erosion rates of three traditional and one improved system, based on 1988-89 field data. Although rates were unacceptably high in all systems, the alternative system recommended by Plan Sierra (Conuco PMA) exhibited substantially less soil loss than the traditional shifting cultivation, cassava and guandul monocultures. The Conuco PMA's positive performance seems related to the continuous soil cover provided by intercropping, mulching and rotations, as well as the shortening of the slope and sediment capture produced by alley cropping and living barriers.
Plan Sierra's simple but effective methods of estimating soil loss are providing useful data. In most cases, measured erosion rates obeyed the determinants of slope, rainfall and soil cover. Given the ecological variety of the area, however, it is difficult to generalize across systems.
Re-creating Incan agriculture
In Peru, a new enthusiasm for ancient technologies extended to rescuing an ingenious system of raised fields that evolved on the high plains of the Peruvian Andes about 3 000 years ago. These waru-warus, consisting of platforms of soil surrounded by ditches filled with water, were able to produce bumper crops in the face of floods, droughts and the killing frosts common at altitudes close to 4 000 metres. Around Lake Titicaca, remnants of more than 80 000 ha of such platforms can still be seen.
In 1984, several NGOs and state agencies created the Proyocto Interinstitutional de Rehabilitation de Waru-Waru en el Altiplano (PIWA) to assist local farmers in reconstructing the ancient farms. The combination of raised beds and canals has proven to have remarkably sophisticated environmental effects. During droughts, moisture from the canals slowly ascends to the roots via capillary action, and during floods, the furrows drain away excess runoff. Waruwarus also reduce the impact of temperature extremes. Water in the canals absorbs the sun's heat by day and radiates it back at night, helping to protect crops from frost. On the raised beds, night temperatures can be several degrees higher than elsewhere. The system also maintains soil fertility. In the canals, silt, sediment, algae and plant and animal remains decay into a nutrient-rich muck which can be dug out seasonally and added to the raised beds. Soil analysis of samples from reconstructed waru-warus showed increased levels of nitrate nitrogen, phosphorus and potassium, as well as a pH ranging from 4.8 to 6.5, optimal for potato growth.
These environmental effects determined the high productivity of the waruwarus, compared to that of chemically fertilized pampas soils. In Huatta District, waru-waru fields exhibited a sustained potato yield of eight to 14 tons per hectare per year, comparing favorably with the average Puno potato yields of one to four t/ha/yr. In Camjata, potato yields reached 13 t/ha/yr and quinoa yields reached two t/ha/yr in a 12-hectare waru-waru area built by local farmers with the assistance of an NGO, the Centro de Investigacion, Educacion y Desarrollo (CIED).
This ancient Incan technology is proving so productive and inexpensive that it is being actively promoted throughout the Altiplano in preference to modern agriculture. It requires no modern tools or fertilizers. The main expense is for labor - requirements vary from 200 to 1 000 worker days/ha - to dig canals and build up the platforms.
In situ conservation in Chile
The archipelago of Chiloe, a group of islands in southern Chile, is one of the centres of the potato Solanum tuberosum L., and collecting expeditions by researchers over the years found a great diversity of native potato varieties. In 1975, Chilean botanists collected 146 different samples of native varieties, the most prevalent being so-called michunes coloradas y moradas and the clavelas. These varieties are highly adapted to the region's range of ecological conditions and are crucial to subsistence production.
Starting in the early 1940s the Chilean government introduced several European and North American varieties (some originally bred from Chilotan material). In areas close to urban and market centres, farmers have abandoned most native varieties and adapted such introductions as Desiree, Industrie, Condor or Ginecke, which have greater commercial demand. Not only have these introductions contributed to the extinction of native varieties, but they brought diseases with them (Ceres No. 130). Around 1950, Phytophthora infestans devastated most potato fields, especially damaging native varieties that had never been exposed to the exotic pathogen and hence lacked resistance.
To slow genetic erosion and recover some of the native potato germplasm, the Centro de Educacion y Tecnologia (CET) initiated an in situ conservation program at its peasant training centre in Notuco, near Chonchi, as well as in several neighboring communities. In 1988, CET technicians surveyed several farm areas of Chiloe and collected hundreds of samples of native potatoes still grown by small farmers. A live collection (garden seed bank) of 96 native varieties was established at Notuco, with varieties planted in rows of five to 10 plants in a 0.5 ha plot. Varieties are grown every year, and subjected to selection and seed enhancement.
In 1990, CET initiated an in situ program involving 21 farmers in five rural communities (Dicham, Petanes, Huitauque, Notue and Huicha). Each farmer is given samples of five varieties to grow in his potato fields. After harvest, farmers return part of the seed production to CET for its garden bank, exchange seeds with other farmers, or plant the seeds again. As more farmers are involved in the project, CET will be able to select varieties based on farmers' actual needs and locally desirable characteristics. Selected varieties will be propagated and distributed among the farmers. Excess seeds could also be sold or exchanged for seeds of traditional varieties not yet in CET's collection. This will allow a continuous supply of valuable seeds to resource-poor farmers for subsistence, as well as create a repository of genetic diversity for future regional crop improvement programs.
Designing integrated systems
Since 1980, CET has engaged in a rural development program aimed at helping peasants reach year-round food self-sufficiency while rebuilding the capacity of their small landholdings. The approach has been to set up several 0.5 ha model farms where most food requirements for a family with little capital can be met. The critical factor is diversity. Thus crops, animals and other farm resources are assembled in mixed and rotational designs to optimize production efficiency, nutrient cycling and crop protection.
The model farm is a combination of forage and row crops, vegetables, forest and fruit trees, and animals. Components are chosen according to crop or animal nutritional contributions, their adaptation to local agroclimatic conditions, local peasant consumption patterns and, finally, market opportunities. Most vegetables are grown in heavily composted raised beds (five by one metre each) located in the garden section, each of which can yield up to 83 kg of fresh vegetables per month. The rest of the 200-square-metre area surrounding the house is used as an orchard, and for animals (a jersey and holstein cow, a sow, 10 laying hens, three meat rabbits and two Langstroth beehives). The rest of the vegetables, cereals, legumes and forage plants are produced in a six-year rotational system within a 4 200 m2 area adjacent to the garden. Relatively constant production is achieved (about six tons per year of useful biomass from 13 different crop species) by dividing the land into as many small fields of fairly equal productive capacity as there are years in the rotation. The rotation was designed to produce the maximum variety of basic crops in six plots, taking advantage of the soil-restoring properties and built-in biological control features of the rotation. Thus each plot receives the treatments described in Figure (b) throughout the six-year period.
CET personnel have monitored these systems' performances closely. Throughout the years, soil fertility has improved (P205 levels, which were initially limiting, increasing from five to 15 parts per million) and no serious pest or disease problems have been noticed. Fruit trees in the orchard and around rotational plots produce about 843 kg of fruit per year (grapes, quince, pears, plums). Forage production reaches about 18 tons per 0.21 ha per year. Milk production averages 3 200 litres per year, and egg production reaches a level of 2.531 units. A nutritional analysis of the system based on its production components (milk, eggs, meat, fruit, vegetables, honey) shows that it produces a 250 per cent surplus of protein, 80 and 550 per cent surpluses of vitamins A and C, respectively, and a 330 per cent surplus of calcium. A household economic analysis indicates that, given a list of preferences, the balance between selling surpluses and buying preferred items is a net income of US$790. If all of the farm output is sold at wholesale prices, the family could generate a net monthly income 1.5 times greater than the monthly legal minimum wage in Chile.
Farmer groups from local and distant areas live on CET's farms
for variable periods of time, learning by participation in planning, management
and evaluation of the organic production systems. After training, they are given
a packet of the seeds needed to set up a similar system of their own, and return
to their communities to teach their neighbors the new methods. Follow-up
evaluations in rural communities reveal that many peasants adopt a portion or
all of the CET design, in many cases modifying the technologies according to
their own lore and resources.
Two crucial dimensions
The challenges of Latin American agriculture are socio-economic and environmental, as well as technical. In this decade, they include two crucial dimensions: the ecological management of peasant agricultural resources, and the transformation of peasant communities into actors in their own development. Many NGOs have already adapted to these imperatives.
Examination of NGO projects applying agro-ecological concepts indicates that many of their proposed technologies and designs are highly productive and sustainable, as well as socio-economically and culturally compatible. In marginal environments, especially, they appear to be capable of greatly improving the resource base, along with the wellbeing of farm communities.
In contrast, development projects emphasizing such capital-intensive, high-input technologies as mechanization, agrochemicals, or imported seeds are proving ecologically unsound, as well as socially inequitable due to their tendency to benefit only a small portion of local populations. In terms of hectares planted, eucalypts - including more than 600 species of the genus Eucalyptus - may be the world's most popular trees.
Yet they may also be the most hated: Portuguese peasants brand them "fascist trees" or "capitalist trees", charging they bring profits to landowners and industrialists at the expense of the environment and the livelihoods of smallholders. In Iberia, they are seen as the deadly foe of the venerable cork oak (Ceres No. 127). Villagers in India, Thailand, Spain and Portugal have uprooted seedlings by the thousands, battled police and chained themselves to tractors to stop land from being cleared for eucalyptus plantings. Throughout much of Asia, the trees have such a reputation for being "detrimental to development" that donors shy at the very mention of their name. Planting eucalypts has been banned altogether in Kenya and parts of Burma (Myanmar).
That such hostility has developed toward such seemingly inoffensive things as plants can be traced to the real virtues of the trees themselves and the too-frequent vices - shortsightedness, silvicultural and environmental ignorance, sometimes outright greed - of growers.
Most maligned of trees
The eucalypts' defenders insist they are the most maligned of trees, not bad in themselves, only badly used. As Dr Y.S. Rao, senior forestry officer in the Bangkok Regional Office of the UN Food and Agriculture Organization (FAO), recently told Depthnews Science Service: "If you plant the wrong species in the wrong place for the wrong reasons, you are going to be disappointed, possibly dismayed, at the tree's performance". Eucalypt specialist and FAO consultant Chris Davis agrees. "How can you write off an entire genus, which has hundreds of species?" he asks. "What is important is to know how and where and when to plant. Whether you use eucalyptus or not depends on your needs".
Native to the islands east of the so-called Wallace's Line from Australia, where it is called the gum tree, south to Tasmania and north to the Celebes, Papua New Guinea, Indonesia, Borneo and Java, the eucalyptus genus takes its name from the Greek eu, meaning well, and kaluptos, meaning covered, the latter referring to the trees' covered flowers. Generally fast-growing and highly adaptable, eucalypts can produce large quantities of wood in poor soil, with little labor. They are cultivated in more than 100 countries, and new species are still being discovered. These may range from towering giants of 90 metres to dwarfs known as "mallees", which have large underground stems that enable them to grow in scrub where there is little rain. Some species form dense foliage and big crowns, making them useful for ground cover, as well as timber, poles, etc.
Probably first grown outside their natural habitat in Portugal
about 400 years ago, their first major plantings were in South Africa and Brazil
around 1904. Brazil's research and hybridizing programs, dedicated largely to
industrial needs, have given it the highest mean annual growth rate per hectare
in the world. The country has well over one million hectares of eucalypt
plantations, providing 60 per cent of its wood for industrial purposes. Brazil
may, in fact, be too enthusiastic a patron: in 1990, the government announced -
in the face of vociferous protests from ecologists and indigenous people - that
it would reforest one million ha of recently logged land in Amazonia, not with
threatened indigenous species, but with more eucalypts for timber and pulp
Thrive in extremes
Eucalypts thrive in extremes of latitude and altitude. Eucalyptus globulus, which occurs naturally between latitudes of 38.5 to 43.5 degrees S and under 1000 m altitude, grows equally well in Ethiopia at a latitude of 12 degrees N and altitude of 2 500 m, in the Nilgiri Hills of India at a latitude of 17 degrees N and altitude of I 000 m, and in the Andes Mountains of Peru at latitudes of five to 10 degrees S and an altitude of 3 000 m. In 1955, there were an estimated 700 000 ha of eucalypts throughout the world; 25 years later there were almost four million ha, with plantings increasing by more than 175 000 ha a year.
Clearly, if it's being planted this widely, the genus has its pros as well as its cons. The pros: The outstanding traits of eucalypts are the variety of their uses and the speed and ease with which they grow. They can mature and reach a height of 10 m in as little as five years, and can be harvested every four to eight years. For at least three or four harvests they don't have to be replanted because of their "coppice vigor" - they resprout from the original stump.
The trees provide fuelwood, poles and posts, pulp, paper, raw material for reconstituted wood products, nectar for honeybees and oils and tannins for perfumes and medicines. They also serve as shelterbelts and create rapid tree cover. Eucalpyt branches with their decorative blue-green leaves are also a staple of florist shops, and the trees are widely grown as decorative landscape species.
The cons: Planted as exotics, eucalyptus trees generally do not provide fodder, fruit, food or a habitat for wildlife. They tend not to enrich the soil, and if planted on the wrong site may sometimes even affect it adversely. Commonly grown varieties with sparse canopies do not give shade or protect the soil against erosion as well as some other species. Monocultural plantations invite pests and can threaten the environment. Many eucalypts compete with agricultural crops, absorbing large quantities of water and the often scarce supplies of micro-nutrients needed to sustain rapid growth.
Worse still, eucalypt plantations offer few local jobs (though some may open up in distant sawmills) and may upset local, communal traditions, such as grazing agreements.
But there is more to the eucalypt dilemma than balancing the pros against the cons. Some of the cons have their pro aspects, and others have more gray than black marks against them.
Trees are like goats
Davis compares eucalypts to goats. "They are the perfect design. Like goats, they can live anywhere, eat anything. And like goats, they also eat things you don't want them to", he says. The trick is to manage them in such a way that they eat only what you want them to.
The large amount of water eucalypts consume is a drawback, but their consumption is extremely efficient by unit of biomass produced, and they need less water than pines do. This thirst can be turned into a virtue by using it to drain swampy areas, or to fight salinity (Ceres No. 127). Digging narrow trenches along the edges of a eucalypt plantation will stop tree roots growing out sideways to compete for water with nearby crops.
Because the trees usually don't provide fodder - except for Australia's koala bears, which feed on eucalyptus leaves - they can be grown to form fences without having to protect the seed-rings and young trees from grazing cattle. While the shoots and branches are not tempting, the Chinese have extracted oils from eucalypts on which livestock will feed and fatten.
Whether eucalypts help or harm the soil depends on which species are planted and how they are managed. Recent studies in India and the Mediterranean show that eucalypts had a beneficial effect on soil structure, comparing favorably with pine and, in India, Shorea rohusta (sal). Planted on formerly treeless sites, their decayed leaves and litter improved soil fertility. Cropping the trees young, as often happens in plantations of eucalypts grown for industrial uses, and removing the biomass, removes some nutrients that otherwise would be cycled between trees and soil. Eucalypts do not fix nitrogen in the soil but, according to Davis, "Nitrogen-fixing is not necessarily a panacea. You have to have reasonable soil containing the nitrogen first". And one of the virtues of eucalypts is that they can grow in less-than-reasonable soil. Davis says foresters are now experimenting with growing eucalypts in combination with nitrogen-fixing acacias, which are native to almost every part of the world.
When eucalypts are planted as an exotic monoculture. replacing natural forest, the indigenous forest ecosystem is destroyed, depriving local wildlife of habitat. But, Davis points out that Australia's natural eucalypt forests are full of wildlife. Again it is a case of which eucalypts are planted, where and how. A mixture of exotic species grown in multipurpose plantations to provide fuel and timber can also attract animals and birds that used to live in natural forests if there are occasional open spaces and undergrowth is left untouched here and there. The FAO reports that in India's Karnataka State, scene of violent anti-eucalypt demonstrations, the progressive reforesting of grassland in the Rannibennur Blackbuck Sanctuary with Eucalyptus tereticornis, which grows well in very dry climates, has led to an increase of wildlife species that had almost disappeared, like the blackbuck (antilope cervicapra), great Indian bustard (Choriotis nigriceps) and wolf (Cants lupus). Strips of exotic trees planted along roadsides in India have attracted large numbers of partridges.
The dangers of competition between eucalypts and other plants can also be minimized by better management. Farmers in India have planted eucalypts with elongated crowns and vertical roots along farm boundaries. The eucalypts do not noticeably reduce field crop yields, and the farmers can sell the produce of the trees. In Colombia, single trees are grown along field boundaries for pulpwood. Eucalypts can have a decidedly beneficial effect on agriculture when planted as a shelterbelt, protecting crops from strong winds in hot, dry climates. Because they are hardy and do not tempt the palates of grazing herds, eucalypts establish themselves easily and quickly. They can serve to start a shelterbelt, after which other trees can be added to yield fruit, fodder and firewood.
Social considerations, however, are crucial and, in the eyes of many critics, too often completely ignored. When eucalypt plantations intrude on land that rural people need for crops or grazing, and provide no alternate employment for them in return, upheavals are inevitable.
Theodore Panayotou, a fellow of the Harvard Institute for International Development working at the Thailand Development Research Institute, told the Thai magazine Manager that Thailand's severe problem of forest encroachment grows out of land-use conflicts. "There is little sustainable about eucalyptus plantations on encroached forest lands unless the problem of land rights is solved first". In extreme cases, he said, rural people occupying forest reserves are termed illegal occupants and driven out with no compensation, even though they were taxed for the lands and settled on them before they became forest reserves. "No one yet is facing the real issue head-on. The two critical problems are the natural forest and the rural poor. We are losing sight of both for the eucalyptus", Panayoutou warned.
Five key questions
Y.S. Rao poses five questions that should be asked before planting eucalypts:
(1) Is the purpose to put the land under the best use, in terms of economics, and obtain the maximum return on investment?
(2) Is the purpose to generate wood at the fastest possible rate to meet needs within the country and, if possible, earn export revenues?
(3) Is the purpose to provide tree cover for denuded or degraded sites using the species that has the best chance of surviving and growing?
(4) Would eucalypts be planted in agricultural areas where they would compete with crops for water and nutrients?
(5) Would eucalypts be planted in areas where local people need grazing land for their cattle?
Rao's advice is that it probably would be a good idea to plant eucalypts in the first two cases, and definitely in the third. It is a more efficient producer of wood and biomass than most other trees - always keeping in mind its high water and nutrient requirements - and can be ideal for reclaiming wastelands. In the last two cases, however, planting eucalypts would likely lead to trouble, because they would deprive agricultural crops and grasses of water, while their leaves are not palatable to cattle.
Really, such rules of thumb are only common sense. There is no such thing as a "bad plant", much less a fascist one. There are only poor land-use planners - who fail to see the forest for the eucalyptus trees-or, worse, no planning at all.