The following has been extracted from a 2015 training course in agroecology offered throughout South East Asia and in Africa:
THE conventional system of agriculture came about due to the influence of four schools of thought. The first (arising from De Cartes) was to break up the whole and study the different parts in detail; scientists and agronomists would then specialize. However, this ignores the need for a science that integrates everything and looks at the system in a systemic, holistic way.
The second approach emerged when Darwin introduced the concept of the survival of the fittest. However, he failed to see there is much more cooperation and interaction in nature than competition. His theories influenced biologists and economists to focus on competition.
The third approach is based upon von Leibeig’s theory that there will always be a factor that will limit productivity, so in order to reach optimal productivity one must overcome the limiting factor. Therefore, for example, if your limiting factor is nitrogen, you have to add nitrogen; if the limiting factor is a pest, then you have to remove the pest. However, this approach ignores the fact that the limiting factors are symptoms of a deep ecological dysfunction and that attacking the symptoms only creates more problems. When we control one limiting factor, another arises.
With chemical inputs, yields increase up to a point and then decrease. For example, yields do not increase at the same rate as applying nitrogen fertilizer. Conventional agriculture concludes that it is the variety that is not being responsive and thus, a new variety is needed. However, yields decrease because of too much chemical fertilizer in the soil, which makes it acidic. This in turn affects microbial communities and availability of other nutrients in the soil. Also, when we apply chemical fertilizer, it is very soluble and the nitrogen that is absorbed by the plant cannot be metabolized into protein and amino acids. The free nitrogen in the foliage attracts and stimulates insect pests such as aphids that use nitrogen for reproduction.
Agroecology, on the other hand, examines the root cause of the problem instead of addressing the symptoms. In this case, using legumes to put nitrogen into the soil would be a better alternative, as the nitrogen is slowly released and does not lead to nitrogen accumulation in the foliage. Many researchers have found that increases in fecundity and developmental rates of aphids are highly correlated with increased levels of soluble nitrogen in leaf tissue. The idea that chemical nitrogen fertilizer inhibits protein synthesis, making plants more susceptible to pests and diseases, was advanced by French scientist F. Chabboussau in the 1960s.
The fourth approach was based on Malthus who theorized that the gap between population growth and food productivity is hunger and the solution is to produce more food. Malthus had a big influence on the Green Revolution, which focused on increasing productivity through yields, above all else. Thus conventional agriculture is obsessed with closing the “yield gaps” between production that highly subsidized farms obtain in the North and that of poor farmers in the South.
Agroecology is a science, a practice and a movement. It is based on scientific and traditional knowledge. It is a science that bridges ecological and socio-economic aspects. It can work at various levels – farm, community, national, regional, and so on. Biological processes are enhanced using agroecological principles and these principles can be shared via farmer-to-farmer exchanges.
Agroecology needs to be built from the bottom up, especially through social movements in rural areas. There is a need to create alliances between rural and urban communities. Agroecology is a pillar of the food sovereignty framework which promotes the provision of land, water, seeds and other productive resources to small farmers and landless people, along with economic opportunities.