In the tropics, cowpea is often intercropped with maize. Little is known about the effect of the intercropped maize on N2-fixation by cowpea or how intercropping affects nitrogen fertilizer use efficiency or soil N-uptake of both crops. Cowpea and maize were grown as a monocrop at row spacings of 40, 50, 60, 80, and 120 cm and intercropped at row spacing of 40, 50, and 60 cm. Plots were fertili...
