A staggered maize–legume intercrop arrangement robustly increases crop yields and economic returns in the highlands of Central Kenya

Abstract

Smallholder farmers in East-Africa commonly intercrop maize (Zea mays L.) with grain legumes to maximize utilisation of land and labour, and attain larger crop yields. Conventionally, one legume line is intercropped between each pair of maize lines. This study evaluated the potential of a modified two-bytwo staggered arrangement (MBILI) to increase crop yields and economic benefits in two sites in Central Kenya with contrasting soil fertility levels during 7 consecutive seasons. Common beans (Phaseolus vulgaris L.), cowpea (Vigna unguiculata (L.) Walp.) and groundnut (Arachis hypogaea L.) were grown as legume intercrops. The MBILI system resulted in increased maize yields in both sites, and increased cowpea yields in the poor site. In the fertile site, using beans as an intercrop was most profitable, and the MBILI system increased net benefits by 40%, relative to the conventional system. In the poor site, groundnut and cowpea were better adapted, and the MBILI system increased net benefit by 12-37%. Positive effects of the MBILI system were most pronounced in the poor site, but occurred independent of soil fertility level. Rainfall amounts and distribution varied widely, but the MBILI system increased yields both under conditions of ample and inadequate rainfall. N balances were negative with beans and groundnut, but neutral with cowpea as the intercrop. A modest N fertilizer application is therefore essential to sustain yields in the long term, especially when beans or groundnuts are intercropped. In conclusion, the MBILI system, when combined with adjusted nutrient inputs, resulted in superior and robust improvements in crop yields and economic benefits, relative to the conventional intercropping system.

Intercropping of Corn With Some Selected Legumes for Improved Forage Production: A Review

“…Further to that, a delay in sowing of four weeks was long enough to avoid interspecific competition for light and nutrients and allow a good establishment of both maize and roselle (Flores-sanchez et al, 2013). Despite the beneficial effects of the intercropping to the cereal crops, it may also quicken soil nutrient depletion, particularly for phosphorous, due to added efficient use of soil nutrients and higher exclusion through the harvested crops (Mucheru-Muna et al, 2010). However, Chalka and Nepalia (2006) found that maize intercropped with soybean produced significantly lower NPK depletion and higher N uptake.…”

Production, Competition Indices, and Nutritive Values of Setaria splendida, Centrosema pubescens, and Clitoria ternatea in Mixed Cropping Systems in Peatland

“…The value of K SS was higher than K CP and K CT in mixed cropping (Table 3), indicating an advantage of S. splendida over the other legume in the mixed cropping system. The presence of legume improved the growth of S. splendida (Mucheru-Muna et al, 2010). Legume root systems did not give tough competition to the grass (Refliaty et al, 2009), as the grass acquire N from legumes through the decomposition and mineralization of N-rich legume plant litter and N transfer from the legume to grass (Pirhofer-Walzl et al, 2012).…”

Intercropping Barley (Hordeum vulgar L.) and Lentil (Lens culinaris L.): Yield and Intercropping Advantages

“…Others investigators have shown that intercropping of cereals and legumes produce higher grain yields than either sole crop (Mpairwe et al, 2002;Mucheru-Muna et al, 2010). In such intercropping, the yield development of the cereal component (Dahmardeh et al, 2010).…”