Research Article

My research was about modelling routes for legume integration into maize systems in Zambia for water use efficiency.

Small holder farmers in Zambia are faced with challenges of land ownership, agricultural input availability and water stress. Also, agricultural land is characterized with eroded and depleted soils, yet the country’s agriculture continues to be a monoculture. Coupled with the climate crisis, agriculture production and productivity remains threatened. The study was done to model legume integration routes into maize systems for water use efficiency in Zambia and to determine the yield and evapotranspiration of the individual legume integration route. The study employed DSSAT v4.7.5 to simulate crop rotations of maize with four different grain legumes including groundnuts (Arachis hypogea), cowpea (Vigna unguiculata), soybean (Glycine max) and common beans (Phaseolus vulgaris). A total of twelve soils were identified in agroecological zones I, IIa, IIb, and III of Zambia. For each soil weather data was collected for a period of 25 years with 1994 as the base year and weather stations were created in the DSSAT weather module, weatherman. Consequently, for each crop sequence, simulations were run over a period of 25 years. The study shows that WUE of maize systems rotated with different legumes varies from one location to the other. This can be attributed to the fact that specie’s genetic make-up and its interaction with the environment around it, contributes to the WUE of the next crop. The positive WUE results can be linked to the yield increase and reduction in the evapotranspiration of Maize systems when rotated with legumes. It is recommended that any legume can be included in maize systems for WUE within a given soil. However, comparing between soils, groundnut is recommended in Calcic Solonetz soils (AEZ I), Haplic Acrisol (AEZ IIa), Luvic Phaeozem (AEZ IIa), Eutric Cambisol (AEZ IIa), Gleyic Arenosol (AEZ IIb) and Ferralic Cambisol soil (AEZ III).  Meanwhile soybeans (Glycine max) can be recommended for inclusion in maize systems in Carbic Podzol soils (AEZ IIb), Haplic Lixisol (AEZ I), and Haplic Ferralsol soils (AEZ III). It can also be recommended that dry bean (Phaseolus vulgaris), should be rotated with maize systems on Haplic Acrisol soils (AEZ III).