Response of pigeonpea to short-term water stagnation in a moderately sodic soil under field conditions

Saturated and/or temporary flooding conditions, following irrigation or rains during the growing season of crops, are common in poorly permeable soils in the Indo-Gangetic alluvial plains of Northern India leading to low yield of crops. A field study was, therefore, conducted to evaluate the effects of short-term water stagnation on growth, yield and mineral composition of pigeonpea (Cajanus cajan L.) in a partially-reclaimed sodic soil (pH₂ 8.8, ESP 22). Water stagnation treatments were applied at vegetative (35 days after sowing), flowering (75 days after sowing) and at both vegetative and flowering stages for 0 (drained), 1, 2, 4 and 6 days. Water stagnation for 1, 2, 4 and 6 days significantly reduced plant height, branching, dry matter, number of pods and resulted in 7.9, 13.2, 17.1, and 23.7% reduction in grain yield, respectively. Water stagnation decreased oxygen diffusion rate (ODR) and reduced ion uptake, especially of N, P, K, Zn, Cu and increased the absorption of Na, Fe and Mn. The detrimental effects were greater when the crop was subjected to water stagnation at both the stages. The results of this study clearly indicated that to ensure optimum yield of pigeonpea in partially-reclaimed sodic soils during the kharif season in monsoon climate, excess water must be drained within one day of irrigation or rains.