A team of researchers from IFPRI, the Kenya Agricultural Research Institute (KARI), and the International Livestock Research Institute (ILRI)—with support from the World Bank—collected data from more than 700 farm households in Kenya distributed across various agroecological zones and soil types. The team then used the data in simulations to show how various farming practices would affect crop yields, soil quality, and greenhouse gas emissions.
More Than Fertilizer
Several farm practices came up triple winners. One such practice, says Elizabeth Bryan, a senior research analyst with IFPRI and member of the research team, is soil nutrient management—which involves more than sprinkling some fertilizer on a plot of land. “This isn’t just about using inorganic fertilizers,” says Bryan, “but also manure, mulch, and crop residues.”
By combining crop residues, fertilizer, mulch, and manure, farmers in most agroecological zones and on most soil types significantly boosted their net revenue from maize. They did face costs—they had to purchase fertilizer, and sometimes feed for livestock to replace maize stover—but in most cases these costs were outweighed by the increased profits from productivity gains. This combination of soil inputs also improves soil’s fertility and water-holding capacity, making farms more resilient to climate change. And it helps soils store carbon, reducing future climate change.
Another promising strategy is improved livestock feeding. Kenyan farmers feed their dairy cattle crop residues such as maize stover or graze them on rangelands or roadsides. If farmers replaced some of the stover in the cows’ diets with locally available, higher-energy feeds like napier grass and Desmodium, they could both increase production of milk and cut emissions of methane, a potent greenhouse gas, for each liter of milk produced.
These practices have great potential to increase farmers’ crop and livestock production in Kenya’s various agroecological zones, says Barrack Okoba, principal research scientist at KARI and a member of the research team. “The findings should be of great interest to policymakers who want to reduce conflicts over resources and find ways to help the most vulnerable farming communities adapt to climate change,” he says.
And given that resources are scarce everywhere, practices that address several problems at once can be especially cost-effective. As Bryan says, “Why not promote practices that provide multiple benefits for producers and for the environment?”
For more information on this topic:
Detailed results from the study of “triple wins”
- Agricultural Management for Climate Change Adaptation, Greenhouse Gas Mitigation, and Agricultural Productivity: Insights from Kenya, by Elizabeth Bryan et al., 2011.
A blog about the research project