Evaluation of maize-based intercropping on runoff, soil loss, and yield in foothills of the Indian sub-Himalayas

Soil and nutrients losses due to soil erosion are detrimental to crop production, especially in the hilly terrains. An experiment was carried out in three consecutive cropping seasons (2012-2015) with four treatments: sole maize; sole maize with plastic mulch; maize and cowpea under plastic mulching; and maize and soybean under plastic mulching in randomized block design (RBD) to assess their impact on productivity, profitability, and resource (rainwater, soil, and NPK nutrients) conservation in the Indian sub-Himalayan region. The plot size was 9 x 8.1 m with 2% slope, and runoff and soil loss were measured using a multi-slot devisor. The results showed that mean runoff decreased from 356 mm in sole maize with plastic mulch plots to 229 mm in maize + cowpea intercropping with plastic mulch, representing a reduction of 36% and corresponding soil loss reduction was 41% (from 9.4 to 5.5 t ha(-1)). The eroded soil exported a considerable amount of nitrogen (N) (13.2-31.4 kg ha(-1)), phosphorous (P) (0.5-1.7 kg ha(-1)), and potassium (K) (9.9-15.6 kg ha(-1)) and was consistently lower in maize + cowpea intercropping. The maize equivalent yield (MEY) was significantly higher in maize + cowpea with plastic mulch intercropping than the other treatments. These results justify the need to adopt maize with alternate legume intercrops and plastic mulch. This strategy must be done in a way guaranteeing high yield stability to the smallholder farmers of the Indian sub-Himalayan region.

Automated summary

In the Indian sub-Himalayan region, intercropping maize with cowpea under plastic mulch significantly reduces runoff and soil erosion while increasing yield.