North American farmers have made significant progress on adapting to and even mitigating climate change, driven by a combination of public and private research investments and their own observational skills, trial and error, and competitive spirit to get better at what they do. Progress has been documented in a number of ways:

• The rate of fertilizer farmers applied to their crop flattened starting in the mid-1980s, even as corn yields continued to climb and consistently set new records (Figure 1). This is possible because modern hybrids turn nutrients, like nitrogen, phosphorus and potassium (N-P-K) into grain more efficiently, while also using water more efficiently;
• Soil health is improving due to a combination of fertilizer usage, less tillage and returning high volumes of crop residue to the soil. Soil carbon accumulation is generally favored when higher levels of crop residue are returned to the soil. Note that it is not uncommon for 15 tons per hectare of corn roots, leaves, stalks and cobs to be left in and on the soil each season after the grain is harvested in U.S. cropping systems. 
• Agronomists have documented that high yield environments in North America are expanding due to a combination of improved crop varieties, sound agronomic management and use of inputs, like genetically modified organism traits, crop protection products (herbicides, fungicides, insecticides) and chemical fertilizers (N-P-K and micronutrients).1,2

In other words, farmers are stepping up and responding to the challenges of climate change, with the help of research and technology transfer.

Does the same potential exist for tropical soils and environments, and in countries where USAID works? Are smallholder farmers able to adapt to, and even mitigate, climate change? The challenges are greater, of course. Highly weathered, tropical soils are mostly being mined of essential nutrients through intensive cropping without the addition of fertilizer, and the micronutrients are often out of balance. “Market failures,” such as extreme poverty, weak government policy, and political unrest, reduce research investment from the private sector. And unlike U.S. farmers returning high volumes of crop residue to the soil, smallholder farmers tend to remove every leaf and stalk of crop residue to use for livestock fodder, cooking fuel or construction. In these areas, access to agricultural inputs and markets by smallholder farmers is often aspirational only. And climate change is predicted to impact select tropical regions to a higher degree than North America. Shorter and more erratic rainy seasons in Africa seem to be on the rise, for example.

Yet science persists, and the same combination of agricultural research (mostly public) and farmer ingenuity has returned impressive results in countries where agricultural research investments have been made. The Ethiopian “maize miracle,” with annual yield gains on par with the best in North America, is the result of more diverse crop rotations, access to fertilizer and modern hybrids and improved storage. Cost of production, on a per kilogram basis, has gone down for Ethiopian farmers, and an estimated 788,000 people have been lifted out of poverty annually, a powerful example of agriculture-led growth and of farmers managing climate change simply through better use of inputs.

Sorghum production in Haiti is another example where sorghum is grown by about one-third of farmers in Haiti and is the second-most important cereal crop by area in the country. Sugarcane aphid (SCA) causes 30% to nearly 100% yield loss in severe outbreaks. To address this threat, SCA-resistant sorghum varieties have been developed, allowing Haitian farmers to once again grow sorghum after years of devastating yield losses from SCA. Incidentally, the same research (from the Feed the Future Innovation Lab for Sorghum and Millet at Kansas State University) has provided U.S. sorghum farmers with more options for SCA management too, lowering the cost of production and making farmers more resilient. SCA resistance was made possible by a combination of modern genomics tools and traditional breeding. As we learn more about the vast genomic potential of sorghum (Figure 2), transgenic and genome editing tools will become more useful and help scientists and farmers prepare early and often for the next pest challenge, predicted to occur more frequently due to climate change and greater global movement of goods, services and people.

Yet another example of success in the tropics is that of Rosette’s disease resistance in groundnuts. Rosette’s is a viral disease, and one of the few management options has been to spray insecticides to kill aphids, the vectors of the virus. The genes and alleles that convey resistance to Rosette’s have now been identified, through modern genomic sequencing tools, which allow groundnut breeders a more rapid and efficient means of developing resistant varieties. While the Rosette’s virus has yet to invade U.S. groundnut production, USAID investments in the Feed the Future Innovation Lab for Peanut at the University of Georgia (Peanut Innovation Lab) and in Africa have prepared U.S. breeders for this disease, if (or when?) Rosette’s disease jumps the Atlantic.

Another USAID investment just getting off the ground is in “direct-seeded rice,” or DSR, in which much less water is used for rice production. The investment includes the International Rice Research Institute (IRRI), national research programs in Africa and Asia and Bayer Crop Science, which is contributing in-kind and subject matter experts for breeding, agronomic management and digital research tools. Flooding of rice paddies in traditional production creates conditions ideal for methane production — a potent greenhouse gas — in the paddies, and paddy rice is among the highest producers of greenhouse gas emissions in agriculture.  DSR reduces the need for early-season flooding, thereby reducing methane production. Other benefits include conservation of the water resource, improved fertilizer use efficiency, healthier soils and less labor and drudgery of replanting rice seedlings. Productivity is maintained, and both climate change adaptation and mitigation are more likely than with traditional paddy rice production.

The examples included here would not have been possible without research investments. For USAID Feed the Future focus countries, public research is critical to progress on the seemingly intractable problems of climate change because of the aforementioned market failures and high risk for the private sector.  

Farmers everywhere are the same — each and every season, they want to get better at what they do and be more productive. Greater access to inputs — crop protection, fertilizer, modern crop varieties and traits — have and will continue to transform the productivity and lives of smallholder farmers. Science-based, evidence-based decision-making and investment in research has profound effects on the well-being of farmers and consumers everywhere, and is the foundation of agriculture-led growth and efforts to adapt to and mitigate climate change.

Sources

1. Assefa, Y., P.V.V. Prasad, P. Carter, M. Hinds, G. Bhalla, R. Schon, M. Jeschke, S. Paszkiewicz, I.A. Ciampitti. 2017.  A new Insight into corn yield: trends from 1987 through 2015  Crop Sci., 57 (2017), pp. 2799-2811; https://doi.org/10.2135/cropsci2017.01.0066
2. Gaffney, J., Bing, J., Byrne, P.F., et al.  2019.  Science-based intensive agriculture: Sustainability, food security, and the role of technology. Global Food Security 23: 236-244; doi.org/10.1016/j.gfs.2019.08.003