Feed the Future strategies for food security are designed not only to accelerate agriculture-led growth and reduce undernutrition, but also to encourage sustainable and equitable management of land, water, fisheries, and other resources.
Feed the Future Intern Christopher Chapman asked soil fertility and conservation agriculture expert Michael Mulvaney to tell us more about the importance of sustainable agriculture.
1. How many people can the world feed?
Mulvaney: The answer is unknown. It comes down to an idea first presented by British scholar Thomas Malthus in the early 19th century. Malthus realized that the Earth has a finite amount of resources, and therefore only a finite amount of people can survive on it at a time. Since Malthus first proposed this idea there have been varying opinions on how many people can survive and thrive based on how well we utilize the finite resources we have.
We can produce a lot of food unsustainably, if we choose. But it is a false dichotomy to say that we can produce less food sustainably. Conservation agriculture (CA), for example, can produce the same amount of food, but in a sustainable way that conserves and improves resources. The environment filters our water, cleans our air, prevents erosion, produces food, and provides other resources and services we need. The challenge is to produce food in a way that enhances our natural resources in order to produce food well into the future.
2. What are the long-term impacts of agriculture/animal husbandry on land, water, and other natural resources?
Mulvaney: The direct effects of traditional plow-based agriculture include increased erosion, depleted soil fertility, increased greenhouse gas emissions, decreased biodiversity, and decreased farm resilience to climate change. The soil that we farm is not a renewable resource on a human timescale; it takes 500 years to build one inch of soil and, on a poorly managed agricultural system, that inch of soil can be washed away in a single rainstorm, so protecting it is critical.
Agriculture has cascading effects at the watershed, national, and international levels. For example, plow-based agriculture increases erosion, which can silt up dams, depleting the fishing resources of downstream communities, and decreasing national power generation. The greenhouse gas emissions associated with agriculture have global implications, but also mean lower soil fertility at the farm level, through carbon mineralization and denitrification (nitrate reduction). We can improve nutrient and water use efficiency using sustainable intensification, while simultaneously improving soil resources.
3. The Feed the Future research strategy focuses around “sustainable intensification,” which you just mentioned. What does that mean?
Mulvaney: We need to increase yields to feed the growing population, but we need to do it in a sustainable way. “Sustainable intensification” means working to increase yields on the same area of land. Some tools for sustainable intensification include the use of CA, increased inputs, improved varieties, and education.
Nature does things best. We need to learn from nature when we design agricultural systems. There is nothing more unnatural than a plowed field. You will rarely see bare soil in nature. You will never see a tilled field or a field with a single species as you do in conventional agriculture. CA is closer to what Mother Nature does, enabling the farming system to replenish its fertility, protect the soil, limit erosion, and produce a sustainable system. A lot of the work we do is not just about yields, but how to become more resilient and resistant to things like climate change and droughts.
For example, farmers we work with in Cambodia didn’t have to replant after a recent drought because they had sufficient soil moisture by eliminating tillage and using cover crops, which increased organic carbon in the soil and protected it from excessive evaporation, allowing the soil to hold more moisture. The farmers who practiced CA didn’t have to replant, while all of their neighbors did, which meant additional cost and late crops for their non-CA neighbors. Farmers see this, and they see it’s working, and that’s how we get adoption.
We act like CA is a new thing, but it’s not—it’s been around for most of human history. Native Americans used to plant with a stick (now called ‘no-till’), put a fish in the hole as fertilizer (‘precision agriculture’), and plant the Three Sisters (maize, beans, and squash; ‘intercropping’). There are lessons to be learned from the way we used to do things, and then include the newer tools we have today, in order to build a sustainable food system that helps the environment and the farmer alike.
4. Where is the most research and work needed to improve agriculture in developing countries?
Mulvaney: I think we need to focus on appropriate tillage and crop management practices. Research, extension, and education work with farmers will be essential to make this happen. Extension work is the transmission of the knowledge we gain through research into practice around the world. You can’t just hand a smallholder farmer a no-till planter and say, “have at it.”
Switching from conventional agriculture to CA is a game-changing event for the farmer. We need to make sure the system works before we can extend it to the farmer because if it fails, the farmers and their families starve. There needs to be education and support to ensure the new methods are beneficial for the farmer and are actually adopted.
Germplasm improvements should play an important role as well. At the low-tech end we have educators who teach farmers how to select the best seeds from their harvest to use again next season. At the high-tech level, researchers can produce specialized plants that have increased yield, drought tolerance, or can withstand higher or lower temperatures, by selecting and breeding for the natural variations that exist in the plant species.
It’s important to realize that none of this research can take place in a vacuum. In many ways, the agronomic solutions are easy. But without integrating economics, sociology, and gender issues, the agronomic solutions may not work. We need real interdisciplinary collaboration to solve these problems.
Michael Mulvaney is a soil fertility and conservation agriculture expert and the assistant director for the Feed the Future Food Security Innovation Lab: Collaborative Research on Sustainable Agriculture and Natural Resource Management* located at Virginia Tech University. The lab supports farmers in developing countries become more sustainable while improving yields with education, tools, training, and research. Follow him on Twitter @TheDirtDude.
*Formerly called the Sustainable Agriculture and Natural Resource Management (SANREM) Collaborative Research Support Program.
Research Blog Series