Sustainable intensification (SI) is a broad concept of enhancing agricultural productivity to meet the future demand for food, fuel and fiber, while protecting environmental services and increasing resilience to shocks. This is key to improving the agricultural landscape in Malawi, where population growth is putting pressure on natural resources, and where the majority of farmers rely on small rainfed agricultural plots. Crop diversification is just one example of a SI technique that is important for enhancing farming system productivity, enhancing resilience to climate variability and change, and improving food and nutrition security.
On 15th August, Daniel van Vugt, a Ph.D. candidate at Wageningen University and Acting Country Manager at the International Potato Center (CIP) in Lilongwe, presented research findings from experiments conducted on SI and diversification practices using legumes and sweet potatoes—both chosen for their environmental and nutritional benefits. Legumes can improve soil fertility and protein intake in rural households, while sweet potatoes are considered more drought tolerant and resilient, in addition to being highly nutritious.
The study involved a range of on-farm agronomic trials and demonstrations across Central Malawi between 2010 and 2017. The study tested multiple technology options to enhance soybean productivity, as well as the rotational effect of soybeans on maize. For sweet potato, the variability of yield performance across six orange-fleshed varieties was assessed. In collaboration with a private sector company, the researchers assessed effects of different combinations of fertilizer and lime in maize, soybean, groundnut, and sweet potato fields. Farmers’ perceptions of technologies and of crop diversification were also explored through focus group discussions and other participatory approaches. Lastly, the study used secondary data on costs of technologies and farm-gate prices of commodities to calculate partial gross margins for farmers’ investments in intensification and crop diversification.
The results showed various promising instances of improved yields. For example, a combination of inoculation, inorganic fertilizer, and compost manure under farmer’s own management nearly doubled soybean yields. Average maize yields under farmer management increased roughly 40 percent from planting after soybeans alone. (For more information on the results, see the additional resources and slides below.)
However, van Vugt emphasized that there was considerable variability in productivity and yield responses to technologies. For example, there was a big difference in yield responses for maize following soybeans relative to continuous maize across regions; in Dowa, about 30 percent of farmers experienced a negative yield response from the rotation.
The research also looked at farmer preferences across technologies and profitability to understand the likelihood of adoption. Farmers indicated that technologies requiring purchase of outside inputs were less preferred than agronomic practices such as early planting, increasing plant populations, using compost manure, etc. The results demonstrated limited awareness of the agronomic and financial benefits of nutrient application to legumes and sweet potatoes among farmers as well. Many prioritized legume production precisely because they thought they did not require fertilization.
These results highlight many promising avenues for increased diversification and yields, but also underscore the difficultly of targeting technologies and approaches to pre-defined farm types. It also raises questions about targeting of programs like the Farm Input Subsidy Program (FISP), which had previously focused on resource-poor farmers and has recently piloted a focus on more productive farmers. Ultimately, solutions to increase agricultural productivity likely need to be more tailored and will necessarily be market-driven; farmers need assurance of a fair market price for their produce in order to invest in new technologies and approaches.
Additional resources
