Pearl millet and cowpea intercrop response to applied nutrients in West Africa

In the Sahel, crop production is dominated by pearl millet [Pennisetum glaucum (L.) R. Br.] cropping systems including intercropping with cowpea [Vigna unguiculata (L.) Walp]. The research objectives were to determine pearl millet sole crop (PMSC) and intercrop nutrient response functions, profit opportunities from fertilizer use, and a means of relating intercrop to PMSC response. Pearl millet–cowpea trials were conducted in Niger and Mali. The treatment structure was an incomplete factorial with five, four, and four levels of P, N, and K, respectively. Response functions were determined for intercropping with cowpea yield converted to a pearl millet grain yield equivalent for ratios of cowpea to pearl millet grain value (CpPm) ranging from 1 to 5 kg kg–1. Response functions were also determined in consideration of fodder value. A method of adjusting PMSC response coefficients with CpPm as the independent variable was developed for determination of intercrop response functions. Yields ...