World population growth is fortunately slowing, although in absolute numbers the population will continue to grow for at least the next 3 decades. Producing enough food to meet our collective needs for sustenance presents humankind with a huge, but not open-ended, demographic challenge.
Climate change, on the other hand, is a more dire threat. Humankind has not yet begun to make the large changes needed to halt the climate trends that make more and more regions of our planet less hospitable to life. The constraints and hazards of climate change fall most harshly and destructively on the agricultural sector.
If we continue trying to produce enough food
according to our prevailing mind sets and methods, there is probably no way that
we can meet increasing world food requirements given the combination of continuing
population growth and accelerating climate change. We need to produce more food
with fewer inputs, both natural (water) and synthetic (fertilisers and
agrochemicals), rather than depending on ever more of these.
What is agroecology?
There is a path that I think can keep food production from being a binding constraint, while we struggle to do what is necessary to restore climatic stability and health. This is the path of agroecology, which is as old as it is new. It brings together agricultural practices that build upon the processes and potential already present within our natural environment.
Using agroecological practices, it is possible to produce more food with less water and fewer external inputs. Many factors are involved, but two major ones include: getting plants to grow larger and better systems; and enhancing the beneficial life in soil – from microbes to earthworms. Microbiomes, we are learning, are as crucial to the growth and performance of plants as human microbiomes are to our own species.
Agroecology shapes agricultural practices and farming systems to gain more benefit from genetic, hydrological-cycle, soil systems, and microbial interactions that have evolved over millions of years. It includes a variety of strategies, such as integrated pest management, agroforestry and aquaculture (as part of farming systems and not as monoculture), new approaches to livestock production and range management, organic farming, water harvesting, permaculture and other methodologies.
The System of Rice Intensification
The System of Rice Intensification (SRI) is an agroecological methodology developed in Madagascar. Farmers do not need to purchase and plant new-variety seeds; they use whatever variety they think best and then manage their plants, soil, water and nutrients according to SRI recommendations. With SRI, farmers do not need to buy and use chemical fertilisers if they can enhance their soil with decomposed biomass, vegetative material and/or animal manure.
Some SRI practices are counterintuitive, and SRI itself made little sense to me when I first learned about it. But its results changed my mind. SRI methods greatly increase crop productivity with benign effects for the environment. The smallholding farm households with whom we worked in Madagascar in the mid-90s, under a USAID project, had been producing only 2 t/ha of paddy rice with their traditional varieties and methods on really poor soils.
With the same seeds and on the same poor soils, these farmers got average yields of 8 t/ha when they used SRI practices. After seeing a four-fold increase in yield for 3 years in a row, I concluded that these methods deserved wider and systematic evaluation. As SRI was used in more and more countries, now over 60, we commonly saw yield increases of 50-100%, and four-fold increases in average yield were reported from communities in Aceh, Indonesia and Madhya Pradesh, India, where farmers were previously producing at very low levels.
While SRI is certainly more labour-intensive than capital-intensive, for most farmers it is labour-neutral, while using less water and with lower costs of production. Once farmers in different countries tried SRI methods and understood its principles, many began extrapolating these ideas to their other crops, such as wheat, finger millet, maize, sugarcane, mustard, tef, various legumes, and many vegetables, with similar beneficial results. These adaptations are referred to now as the System of Crop Intensification (SCI).
SRI and SCI represent ‘climate-smart agriculture’ because crop plants grown with SRI management are less affected by drought, storms, flooding, and extreme temperatures. They are also less susceptible to pests and diseases, so there is less need for agrochemical protection, which makes for better soil health and water quality. These effects derive from having better, deeper root systems, better plant nutrition, and the services of microorganisms in the soil.
By avoiding the continuous flooding of rice fields, SRI also results in substantial net reductions in greenhouse gas emissions from paddy fields. So, together with the reduced application of nitrogen fertiliser, SRI helps to mitigate climate change at the same time that it helps farmers adapt to the hazards of climate change.
SRI and SCI are both still ‘works in progress’, but there is now a large scientific literature base on SRI with over 1,000 published articles. Probably over 20 million farmers are already benefiting from SRI ideas and methods, even though the dissemination has had to proceed country-by-country with little institutional support. However, there is now acceptance from many NGOs and donor agencies, e.g., from FAO, IFAD, Oxfam, and the World Bank.
Although SRI was developed to benefit small-scale, resource-limited farmers in Madagascar, mechanisation can greatly reduce its labour requirements and make large-scale production feasible. With appropriate adaptations and extensions, it should be possible to produce more than enough food for the world’s people in the decades ahead, without imposing further costs on the natural environment and even making improvements in environmental quality.