Agro-Ecological Approaches to Agricultural Development

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This document is part of a series of contributions by Rimisp-Latin American Center for Rural Development ( to the preparation of the World Development Report 2008 “Agriculture for Development”.


Frances Moore Lappé:

" “On every continent one can find empowered rural communities developing GM-free, agro-ecological farming systems. They’re succeeding. The largest overview study, looking at farmers transitioning to sustainable practices in 57 countries, involving almost 13 million small farmers on almost 100 million acres, found after four years that average yields were up 79 percent.

“All over the world,” she continues, “poor farming communities are discovering their own power to work with each other and with nature to build healthier, more secure, and more democratic lives.” (

Executive Summary:

Main Messages for the WDR - Key Principles

"What, then, do we now understand by agricultural sustainability? Many different expressions have come to be used to imply greater sustainability in some agricultural systems over prevailing ones (both pre-industrial and industrialised). Systems high in sustainability can be taken as those that aim to make the best use of environmental goods and services whilst not damaging these assets.

The key principles for sustainability are to:

i. integrate biological and ecological processes such as nutrient cycling, nitrogen fixation, soil regeneration, allelopathy, competition, predation and parasitism into food production processes;

ii. minimise the use of those non-renewable inputs that cause harm to the environment or to the health of farmers and consumers;

iii. make productive use of the knowledge and skills of farmers, so improving their self-reliance and substituting human capital for costly external inputs;

iv. make productive use of people’s collective capacities to work together to solve common agricultural and natural resource problems, such as for pest, watershed, irrigation, forest and credit management.

The idea of agricultural sustainability, though, does not mean ruling out any technologies or practices on ideological grounds. If a technology works to improve productivity for farmers, and does not cause undue harm to the environment, then it is likely to have some sustainability benefits. Agricultural systems emphasising these principles also tend to be multi-functional within landscapes and economies. They jointly produce food and other goods for farmers and markets, but also contribute to a range of valued public goods, such as clean water, wildlife and habitats, carbon sequestration, flood protection, groundwater recharge, landscape amenity value, and leisure/tourism. In this way, sustainability can be seen as both relative and case-dependent, and implies a balance between a range of agricultural and environmental goods and services.

Capital Assets for Agricultural Systems:

What makes agriculture unique as an economic sector is that it directly affects many of the very assets on which it relies for success. Agricultural systems at all levels rely on the value of services flowing from the total stock of assets that they influence and control, and five types of asset, natural, social, human, physical and financial capital, are now recognised as being important. Thus sustainable agricultural systems tend to have a positive effect on natural, social and human capital, whilst unsustainable ones feed back to deplete these assets, leaving fewer for future generations.

Agricultural Side-Effects and Externalities

There are surprisingly few data on the environmental and health costs imposed by agriculture on other sectors and interests. Agriculture can negatively affect the environment through overuse of natural resources as inputs or through their use as a sink for pollution. Such effects are called negative externalities because they are usually non-market effects and therefore their costs are not part of market prices. Negative externalities are one of the classic causes of market failure whereby the polluter does not pay the full costs of their actions, and therefore these costs are called external costs. New data suggest that all types of agricultural systems impose some kinds of costs on the environment. It is, therefore, impossible to draw a boundary between what is and is not sustainable. If the external costs are high and can be reduced by the adoption of new practices and technologies, then this is a move towards sustainability. Agricultural sustainability is thus partly a matter of judgement, which in turn depends on the comparators and baselines chosen. One system may be said to be more sustainable relative to another if its negative externalities are lower. Monetary criteria do, though, only capture some of the values of agricultural systems and the resources upon which they impinge, and so choices may depend on wider questions about the sustainability of farm practices (on farm, in field) and the sustainability of whole landscapes (interactions between agricultural and wild habitats).

Improving Natural Capital for Agroecosystems

Agricultural systems, or agroecosystems, are amended ecosystems that have a variety of different properties. Modern agricultural systems have amended some of these properties to increase productivity. Sustainable agroecosystems, by contrast, have to seek to shift some of these properties towards natural systems without significantly trading off productivity. Modern agroecosystems have, for example, tended towards high through-flow systems, with energy supplied by fossil fuels directed out of the system (either deliberately for harvests or accidentally through side-effects). For a transition towards sustainability, renewable sources of energy need to be maximised, and some energy flows directed to fuel essential internal tropic interactions (e.g. to soil organic matter or to weeds for arable birds) so as to maintain other ecosystem functions.

There are several types of agroecological practices and resource-conserving technologies that can be used to improve the stocks and use of natural capital in and around agroecosystems.

These are:

1. Integrated pest management, which uses ecosystem resilience and diversity for pest, disease and weed control, and seeks only to use pesticides when other options are ineffective.

2. Integrated nutrient management, which seeks both to balance the need to fix nitrogen within farm systems with the need to import inorganic and organic sources of nutrients, and to reduce nutrient losses through erosion control.

3. Conservation tillage, which reduces the amount of tillage, sometime to zero, so that soil can be conserved and available moisture used more efficiently.

4. Agroforestry, which incorporates multifunctional trees into agricultural systems, and collective management of nearby forest resources.

5. Aquaculture, which incorporates fish, shrimps and other aquatic resources into farm systems, such as into irrigated rice fields and fish ponds, and so leads to increases in protein production.

6. Water harvesting in dryland areas, which can mean formerly abandoned and degraded lands can be cultivated, and additional crops grown on small patches of irrigated land owing to better rain water retention.

7. Livestock integration into farming systems, such as dairy cattle, pigs and poultry, including using zero-grazing cut and carry systems.

It has also been argued that farmers adopting more sustainable agroecosystems are internalising many of the agricultural externalities associated with intensive farming, and so could be compensated for effectively providing environmental goods and services. Providing such compensation or incentives would be likely to increase the adoption of resource conserving technologies. Nonetheless, periods of lower yields seem to be more apparent during conversions of industrialised agroecosystems. There is growing evidence to suggest that most pre-industrial and modernised farming systems in developing countries can make rapid transitions to both sustainable and productive farming.

Effects on Yields

It is in developing countries that some of the most significant progress towards sustainable agroecosystems has been made in the past decade. The largest study comprised the analysis of 286 projects in 57 countries. In all, some 12.6 million farmers on 37 million hectares were engaged in transitions towards agricultural sustainability in these 286 projects. This is just over 3% of the total cultivated area (1.136 M ha) in developing countries. In the 68 randomly re-sampled projects from the original study, there was a 54% increase over the four years in the number of farmers, and 45% in the number of hectares. These resurveyed projects comprised 60% of the farmers and 44% of the hectares in the original sample of 208 projects. For the 360 reliable yield comparisons from 198 projects, the mean relative yield increase was 79% across the very wide variety of systems and crop types.

However, there was a wide spread in results. While 25% of projects reported relative yields > 2.0, (i.e. 100% increase), half of all the projects had yield increases of between 18% and 100%. The geometric mean is a better indicator of the average for such data with a positive skew, but this still shows a 64% increase in yield.

Positive Side-Effects

These sustainable agroecosystems also have positive side-effects, helping to build natural capital, strengthen communities (social capital) and develop human capacities.

Examples of positive side effects recently recorded in various developing countries include:

• improvements to natural capital, including increased water retention in soils, improvements in water table (with more drinking water in the dry season), reduced soil erosion combined with improved organic matter in soils, leading to better carbon sequestration, and increased agrobiodiversity; • improvements to social capital, including more and stronger social organisations at local level, new rules and norms for managing collective natural resources, and better connectedness to external policy institutions; • improvements to human capital, including more local capacity to experiment and solve own problems; reduced incidence of malaria in rice-fish zones, increased self-esteem in formerly marginalised groups, increased status of women, better child health and nutrition, especially in dry seasons, and reversed migration and more local employment.

Agriculture is an accumulator of carbon when organic matter is accumulated in the soil, and when above-ground biomass acts either as a permanent sink or is used as an energy source that substitutes for fossil fuels and so avoids carbon emissions.

There are three main mechanisms by which positive actions can be taken by farmers by:

A) increasing carbon sinks in soil organic matter and above-ground biomass;

B) avoiding carbon dioxide or other greenhouse gas emissions from farms by reducing direct and indirect energy use;

C) increasing renewable energy production from biomass that either substitutes for consumption of fossil fuels or replacing inefficient burning of fuelwood or crop residues, and so avoids carbon emissions.

The potential annual contributions being made in the 286 projects to carbon sink increases in soils and trees were calculated to be 11.4 Mt C y-1 on 37 M ha. The average gain was 0.35 t C ha-1 y-1, with an average per household gain of 0.91 t C y-1. These projects also reduced pesticide use and improved water efficiency.

Social Outcomes of Agroecological Approaches

At some locations, agroecological approaches have had a significant impact on labour markets. Some practices result in increased on-farm demand for labour (eg water harvesting in Niger), whilst others actually reduce labour demand (eg zero-tillage in Brazil). Some result in the opening up of whole new seasons for agricultural production, particularly in dryland contexts, through improved harvesting of rainfall, leading to much greater demand for labour. Migration reversals can occur when wage labour opportunities increase as part of the project (eg watershed improvements), when more productive agriculture leads to higher wages and employment, when there are higher returns to agriculture, and when there are overall improvements in village conditions, such as infrastructure and services.

Recent Policy Progress

Three things are now clear from evidence on the recent spread of agroecological approaches:

i. Some technologies and social processes for local scale adoption of more sustainable agricultural practices are increasingly well-tested and established;

ii. The social and institutional conditions for spread are less well-understood, but have been established in several contexts, leading to more rapid spread in the 1990s and early 2000s;

iii. The political conditions for the emergence of supportive policies are least well established, with only a very few examples of real progress.

Most agricultural sustainability improvements seen in the 1990s and early 2000s have arisen despite existing national and institutional policies, rather than because of them. Although almost every country would now say it supports the idea of agricultural sustainability, the evidence points towards only patchy reforms.

Agricultural policies with both sustainability and poverty-reduction aims should adopt a multi-track approach that emphasises seven components:

1. Small farmer development linked to local and domestic markets;

2. Agri-business development – both small businesses and export-led;

3. Agro-processing and value-added activities – to ensure that returns are maximised in-country;

4. Urban agriculture – as many urban people rely on small-scale urban food production that rarely appears in national statistics;

5. Livestock development – to meet local increases in demand for meat (predicted to increase as economies become richer).\

6. Consumer demand for more ethical and natural foods (as urban populations become more wealthy);

7. Supermarket and retail sector changes to connect up consumers with local and domestic producers." (


University of Essex (Professor of Environment and Society, Dept of Biological Sciences), [email protected]