EFFECTS OF SUPPLEMENTAL IRRIGATION AND SOIL FERTILIZATION ON PEARL-MILLET UNDER DROUGHT

Pearl millet was grown under rainfed (188 mm precipitation with an ear ly and a terminal drought) or with one supplemental irrigation (63 mm during the early drought at 10 days after sowing) and with (80 kg N, 1 8 kg P, and 17 kg K ha-1) or without application of fertilizers. Impro vement of soil fertility increased the dry matter and grain yield, wat er use efficiency, mining of soil water, concentrations of some leaf m etabolites (soluble protein, free amino acids, total chlorophyll, and starch), and the activity of nitrate reductase, despite larger decline s of psi(plant) and relative turgidity as compared to unfertilized pla nts under both the rainfed and irrigated conditions. Fertilizer-induce d effects on soil water extraction, crop performance, and metabolism w ere higher under the irrigated as compared to the rainfed condition. I rrigation and soil fertilization showed an additive favorable effect, possibly because of their similarity of action on different plant proc esses, notwithstanding their differential effects on the plant water s tatus.