Author: Clara Inés Nicholls and Miguel Altieri | Published: June 26, 2017
Many studies reveal that small farmers who follow agroecological practices cope with, and even prepare for, climate change. Through managing on-farm biodiversity and soil cover and by enhancing soil organic matter, agroecological farmers minimise crop failure under extreme climatic events.
Global agricultural production is already being affected by changes in rainfall and temperature thus compromising food security. Official statistics predict that small scale farmers in developing countries will be especially vulnerable to climate change because of their geographic exposure, low incomes, reliance on agriculture and limited capacity to seek alternative livelihoods.
Although it is true that extreme climatic events can severely impact small farmers, available data is just a gross approximation at understanding the heterogeneity of small scale agriculture, ignoring the myriad of strategies that thousands of small farmers have used, and still use, to deal with climatic variability.
Observations of agricultural performance after extreme climatic events reveal that resilience to climate disasters is closely linked to the level of on-farm biodiversity. Diversified farms with soils rich in organic matter reduce vulnerability and make farms more resilient in the long-term. Based on this evidence, various experts have suggested that reviving traditional management systems, combined with the use of agroecological principles, represents a robust path to enhancing the resilience of modern agricultural production.
Diverse farming systems
A study conducted in Central American hillsides after Hurricane Mitch showed that farmers using diversification practices (such as cover crops, intercropping and agroforestry) suffered less damage than their conventional monoculture neighbours. A survey of more than 1800 neighbouring ‘sustainable’ and ‘conventional’ farms in Nicaragua, Honduras and Guatemala, found that the ‘sustainable’ plots had between 20 to 40% more topsoil, greater soil moisture and less erosion, and also experienced lower economic losses than their conventional neighbours. Similarly in Chiapas, coffee systems exhibiting high levels of diversity of vegetation suffered less damage from farmers to produce various annual crops simultaneously and minimise risk. Data from 94 experiments on intercropping of sorghum and pigeon pea showed that for a particular ‘disaster’ level quoted, sole pigeon pea crop would fail one year in five, sole sorghum crop would fail one year in eight, but intercropping would fail only one year in 36. Thus intercropping exhibits greater yield stability and less productivity decline during drought than monocultures.
At the El Hatico farm, in Cauca, Colombia, a five story intensive silvo-pastoral system composed of a layer of grasses, Leucaena shrubs, medium-sized trees and a canopy of large trees has, over the past 18 years, increased its stocking rates to 4.3 dairy cows per hectare and its milk production by 130%, as well as completely eliminating the use of chemical fertilizers. 2009 was the driest year in El Hatico’s 40-year record, and the farmers saw a reduction of 25% in pasture biomass, yet the production of fodder remained constant throughout the year, neutralising the negative effects of drought on the whole system. Although the farm had to adjust its stocking rates, the farm’s milk production for 2009 was the highest on record, with a surprising 10% increase compared to the previous four years. Meanwhile, farmers in other parts of the country reported severe animal weight loss and high mortality rates due to starvation and thirst.