Sorghum and groundnut sole and intercrop nutrient response in semi-arid West Africa

Sorghum (Sorghum bicolor L. Moench)–groundnut (Arachis hypogaea L.) intercropping is important in the Sahel and Sudan Savanna. Nineteen trials were conducted during 2014 and 2015 in Mali and Niger for determination of: response functions for sorghum sole crop (SSC) and intercrop to N, P, and K; effects of the P×N interaction and of a nutrient package for diagnosis of other deficiencies; and a procedure for estimation of intercrop functions from SSC response functions. Six Niger on-station trials included treatments for determination of intercrop effects on sorghum yield and response. Mean grain and fodder yield increases for SSC were, respectively, 18.8 and 17.6% with 10 kg ha–1 P, 30.7 and 18.8% with 30 kg ha–1 N, and 0 and 6.8% with 10 kg ha–1 K applied. The diagnostic treatment increased grain yield for only 1 of 19 site-years (SYs). Sorghum grain yield was 30% less with intercropping compared with SSC for 2 of 6 SY but 11% less overall. Overall, sorghum fodder yield was 23% more wit...