Sustainable Agriculture Part 10



EARTHSCAN          2005





Perspective 22: Rethinking Agriculture for New Opportunities by Erick Fernandes, Alice Pell & Norman Uphoff (Cont.)


Monoculture as ‘real’ agriculture

The standard view of agriculture as limited in time and space favours monocropping for achieving control and efficiency in production. Applying inputs is made easier with monoculture, whether calculating fertilizer applications or using mechanical power for weeding. But the conclusion that this is always the most productive way to use land is mistaken. This production method can raise the economic returns to labour or to capital, but it does not necessarily increase the returns to land. The latter resource will become ever more important in coming decades as the availability of arable land per capita declines.

Polyculture systems employing a combination or even a multitude of plants commonly have higher yields per hectare, absorbing and generally requiring higher inputs of labor and nutrients. Where labour is relatively abundant and land is relatively scarce, this can be an efficient and economic system of resource use. The advantage of monocropping is that it makes mechanization, substituting capital for labour, more effective. Only where mechanical power can bring into cultivation land that manual power cannot is greater physical production likely to result from mechanization. This generally makes agriculture more extensive than intensive.

  • Even when population is high in relation to arable area, it can be difficult to attract or retain labour to work in farm operations.
  • Much of the impetus for farm mechanization has come from labour scarcities in the more economically advanced countries.
  • In contrast to tractors, animals used for traction reproduce themselves, pay returns on the farmer’s investment, and provide food, fuel and fertilizer at the same time.
  • Because polyculture is less amenable to mechanization, it requires an adequate and reasonably skilled supply of labour.
  • Many of the practices we discuss here are relatively labour-demanding, using human energy and skill instead of capital and chemicals to get more production from limited land resources.
  • Yields, yield stability and nutritional quality per unit of land from polyculture, although harder to measure, are usually greater than with monoculture.
  • Keeping soils covered protects them against erosion.
  • Polycropping supported by a strategy of managing and recycling organic inputs offers many advantages and can raise yields with equivalent inputs.


Mechanical conceptions of agriculture

Four equations in need of revision

Efforts to raise agricultural productivity have been guided for many decades by four presumptions. These have produced some impressive results, so our objection is not that they are wrong. Rather, they have become too dominant in our thinking, with too hegemonic an influence on policy and practice. It has been taken for granted that they represent superior ways to boost production. This thinking can be stated in four tacit equations have shaped contemporary agricultural research, extension and investment:

  1. Control of pests and disease = application of pesticides or other agrochemicals
  2. Overcoming soil fertility constraints = application of chemical fertilizers
  3. Solving water problems = construction of irrigation systems
  4. Raising productivity beyond these three methods = genetic modification


Equating certain kinds of solutions with broad categories of problems limits the search for other methods to solve those problems, even when alternative practices might have a lower cost and be more beneficial in environmental and social terms. Fortunately, there is a good precedent in the way that the firs equation has ben substantially modified over the past 15 years.

Crops and animals can be protected by non-chemical means

The modern-input paradigm for raising production has been most directly challenged with regard to pest and disease control through integrated pest management (IPM). Adverse effects on human health as well as on the environment caused some scientists to explore ways to produce crops and animals with little or no use of chemicals. Biological controls as well as alternative crop management practices have often turned out to be more cost-effective, and sometimes simply more effective. The chemical-based strategy of ‘zero tolerance’ for pests and diseases, rather than being a solution, exacerbates the problem, killing beneficial insects that are predators of crop pests. The widespread use of agrochemicals, particularly broad-spectrum ones, has had the consequence of making pest attacks worse. Routine use of antibiotics to treat diseases and promote the growth of livestock has, unfortunately, increased the antibiotic resistance of pathogens that can infect humans and/or animals.

An IPM strategy does not preclude the use of chemicals. But the first line of defence against pests and diseases are biological, trying to utilize the defensive and recuperative powers of plants and animals as well as the activity of beneficial and predator insects to farmers’ advantage.

  • The presumption of modern agricultural science regarding chemical means for pest and disease control have been broadly challenged, with such means being increasingly reduced and avoided where possible.


Soil fertility can be enhanced, often more effectively, by non-chemical means

The most broadly successful component of modern agriculture has been the introduction and use of inorganic fertilizers to supply soil nutrients, particularly nitrogen, phosphorus and potassium, where these were lacking. But this success has led many policy makers and some scientists to equate soil fertility improvements with the application of fertilizers when, in fact, fertility depends on many additional factors. Indeed, the misuse or over-use of chemical fertilizer results in adverse effects on yield by negatively affecting the physical and biological properties of the soil. The advantage of inorganic fertilizers is that they are easier to apply, often cheap (if subsidized) and have more predictable nutrient content. Also, organic nutrients are sometimes simply not available in sufficient supply.

When inorganic fertilizers are added to soils that possess good physical structure, with adequate soil organic matter and sufficient cation-exchange capacity, they can produce impressive improvements in yield. Where soils are acidic (low pH) and the nutrients needed for plants are in short supply, the application of appropriate amounts of lime (calcium carbonate) along with inorganic fertilizers can result in spectacular crop yield increases and can greatly increase farmer income. But in many circumstances, especially in the tropics, soils are not so well structured or well endowed. Then, inorganic fertilizers, especially if used in conjunction with tractors that compact the soil, can lead to changes in soil physics and biology that are counterproductive and diminish, sometimes sharply, the returns from adding chemical nutrients.

  • Modern agricultural research’s focus on soil chemistry and above-ground portions of plants has led to solutions that favor chemical and mechanical means.
  • The belief that chemical fertilizers are the best way to deal with soil fertility limitations has arisen from – and has reinforced – the image of agriculture as a kind of industrial enterprise, where producing desired outputs is mostly a matter of investing certain kinds and amounts of inputs.
  • Viewing agriculture more as a biological than as a mechanical process attaches greater value to the use of organic inputs.
  • In recent years there has been a major increase in the application of biologically based technologies, such as vermiculture (raising worms) to enhance soil fertility and ameliorate the negative effects of industrial and agricultural wastes on soil.
  • For plants to utilize chemical fertilizer effectively, the soil in their root zone must have substantial capacity to retain and exchange nutrient cations, and that exchange capacity is considerably enhanced as soil organic matter content increases.


Irrigation is not the only way to deal with water limitations

A mechanistic conception of agriculture reinforces the millennia-old fixation on irrigation as the best if not the only means of providing water for plants in water-scarce environments. In many places, given hydrological cycles and opportunities, irrigation is certainly necessary for the practice of agriculture. But its success over several thousand years has led people to look to this technology as the universal solution to water scarcity problems. When crops need water, the first thought is how to provide irrigation from surface or groundwater sources.

  • When farmers in semi-arid Burkina Faso, assisted by Oxfam, demonstrated that they could grow much better millet crops simply by placing rows of stones across their fields, to slow water runoff and store it in the soil, this was seen as a remarkable technology.
  • Numerous case studies with similar results have been documented.
  • Such practices should become part of the repertoire of soil and water management practices that farmers can adopt to utilize available rainfall most advantageously.
  • Using mulch to capture water and slow evaporation is another simple method.

Measures to conserve and utilize water, like planting crops in certain rotations or seeding a new crop in a standing one to capitalize on residual moisture, should not be seen as something novel but rather as something normal, making the best use of water in combination with soil. Methods including collecting and storing water in small catchment dams, large clay jars or simply in porous soils should be experimented with to determine what designs can provide enough water to crops and animals (and for human uses) to justify the expenditure of labour and capital and sometimes land. Small catchment ponds are becoming more attractive and feasible options, providing water supplies in situ. We should also understand better how land preparation practices affect water retention and utilization.

  • Water scarcity will surely increase for agriculture around the world, so all possible means to acquire and conserve water need to be considered.


Genetic manipulation is not always necessary to raise production significantly

The modern approach to agricultural improvement has stressed better plant and animal breeding, especially since the advent and success of the Green Revolution. Without denying the value of such efforts, or that there will be some future benefits from biotechnology, we think more attention should be paid to cultural practices, to soil preparation and management, to use of organic inputs, to more productive cropping patterns and systems, and to species that have previously been overlooked or underutilized.

Smallholding farmers around the world at present are probably exploiting less than 50% of existing genetic potential of various crops due to less than optimal management. In many cases this is because the returns to labour are not high enough to justify intensification, but often it is a matter of not knowing how to capitalize on synergies that could raise these returns. Reducing the yield variability of traditional varieties and taking fuller advantage of their genetic potential through nutrient cycling and better soil and water management within complex farming systems could, we think, be a cost-effective strategy that complements longer-run and higher-cost biotechnological efforts being undertaken to produce new and better varieties. Increased production of other food sources, including fish culture, small animals and various indigenous plants, can augment in non-competing ways whatever nutrients are provided by staples.

Even if these alternative methods by themselves cannot achieve a doubling of world food production, they could contribute substantially to this, making up the difference that is unlikely to be produced by more modern means that are heavily dependent on inputs of energy, chemicals and water. Capitalizing on ‘non-modern’ opportunities will require reorientation of socio-economic as well as biophysical thinking. It necessitates looking beyond the farm and its fields, and beyond particular crop cultivars, animal species and cultivation practices, to institutions and policies.

Utilizing these productive opportunities

Doing ‘more of the same’ in either the so-called modern or traditional sectors of agriculture is not likely to be sufficient for meeting food needs in the decades ahead. Researchers, extensionists and policy makers who wish to assist households around the world to become more food-secure, healthy and well-off need to consider how to make broadly based improvements in output through evolving systems that are more intensive and more complex. These will resemble but improve upon present practices that are not fully or sustainably utilizing soil, biological and other resources.

Traditional farmers are for the most part quite resource restrained. The technologies offered by extension services were usually developed for larger, simpler production systems that are not appropriate for the kinds of systems that the majority of farmers in the world are managing. There are wide variations in productivity within and across farming communities, with some producers tapping production potentials better than others. We look towards ‘hybrid’ strategies to raise production, combining the best of farmers’ current practices with insights derivable from modern science to tap the power of plant and animal germplasm nurtured under optimal conditions.

There is no reason to believe that the elements of ‘modern’ agriculture are wrong, but neither is there a warrant to consider them (yet) complete. They offer many advantages of productivity and profit for large numbers of agricultural producers – but not for all of them, and maybe not even for a majority of farming households around the world today. Our analysis here calls into question the presumption, whether it is argued or assumed, that mainstream approaches are the best or the only way to advance agriculture in the future. For the sake of productivity and sustainability, it will be advisable to ‘backcross’ some of the modern varieties of agriculture, which are most suitable for advantaged producers and regions, with often more traditional methods so as to develop a more robust ‘hybrid’ agriculture, one that can better meet the world’s needs for food, health, employment and security in this century.

Perspective 23: Soil Recuperation in Central America: How Innovation was Sustained after Project Intervention by Roland Bunch and Gabino Lopez

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