Pearl Millet and Sorghum Yield Response to Fertilizer in the Sahel of Burkina Faso

Sorghum (Sorghum bicolor L. Moench) and pearl millet (Pennisetum glaucum (L.) R. Br.) were domesticated in Africa for human consumption and are often the dominant cereals in semi-arid areas where yield is constrained by soil water deficits, nutrient deficiencies, and other constraints. Research was conducted to quantify yield responses and profitability of sorghum and pearl millet produced in the Sahel of Burkina Faso to fertilizer N, P, K, and a Mg-S-Zn-B diagnostic treatment. Mean yields across trials were 1.2 and 0.9 Mg ha-1 for pearl millet and sorghum, respectively. The effects of N, K, the diagnostic treatment, and interactions were not significant for both pearl millet and sorghum. There was a mean curvilinear to plateau response to P for pearl millet and a linear response to P for sorghum. The economical optimal P rates for pearl millet were modest, ranging from 6 to 33 kg ha–1 at 100% of the rate to maximize net returns per ha to P application when the cost of using fertilizer P was high and low, respectively, relative to the grain price (Table 4). The application of P for pearl millet had high profit potential even with a high cost P use scenario. For sorghum production, P application was not profitable if the cost per kg of fertilizer P use exceeded the value of 9 kg of sorghum grain. The results, therefore, indicate a high and low profit potential for P applied for pearl millet and sorghum, respectively, in the Sahel of Burkina Faso.