Intercropping System Improves Soil Microbiome, Productivity

agriculture-countryside-cropland_-Credit- UNCCD

Smallholder farmers across southern and eastern Africa use the ‘push-pull’ system to manage stem-borers and fall armyworm attacks on cereal crops particularly maize and sorghum, thus increasing yield. The technology exploits the chemical ecology of a leguminous intercrop belonging to the genus Desmodium, which ‘pushes’ stem-boring insects from the main crop through its volatile compounds that signal an unfavourable egg-laying environment. At the same time, a grass trap crop, such as napier grass, is planted as border vegetation to ‘pull’ the insects towards itself without supporting their development.

Additional ecosystem functions gradually emerged to include combating parasitic weeds of cereals (such as Striga spp.), increasing soil nitrogen and carbon, and even reducing incidence of human pathogenic fungal toxins in maize kernels. In addition, both Desmodium and the trap crops are a reliable source of animal fodder. The overall impact is increased cereal yield with minimum chemical inputs.

This study compared the diversity of soil microorganisms between long-term maize-Desmodium and maize monoculture plots. It found that long-term maize–Desmodium intercropping causes a complex shift in the composition of the soil microbiome compared to maize monoculture. Maize–Desmodium intercropping diversifies fungal microbiomes and favors taxa associated with important ecosystem functions including plant health, productivity and food safety.

https://doi.org/10.1007/s11104-021-05082-w

- Third World Network