Maize–cowpea intercropping as an ecological approach for nitrogen-use rationalization and weed suppression

Abstract

Small-scale farmers are harshly suffering from high production costs, and so they permanently try to seek and apply the best cheap practices, bearing in mind that no yield losses occur. The objective of this work was to assess the possibility of lowering applied N rate in maize fields associated with less weeds infestation and keeping/boosting productivity. Thus, a field experiment was conducted to evaluate the response of maize yield and associated weeds to N levels (0, 144, 216, and 288 kg N ha⁻¹) as well as maize (M)–cowpea (C) intercrops, sole-M, MC same ridge, MC alternating ridges, and sole-C. MC alternating ridges intercrop decreased weed biomass by 49.5% compared with sole-M. Sole-M was similar to MC alternating ridges intercrop in producing the maximum maize grain yield per hectare. In plots fertilized with 216 or 288 kg N ha⁻¹, MC alternating ridges were statistically at par with sole-M for enhancing maize grain yield per hectare. Medium N application level (216 kg N ha⁻¹) with MC alternating ridges showed the highest agronomic efficiency (14.6 kg kg⁻¹). MC alternating ridges intercrop can save 26% of the cultivated land.