Impact of Low-pressure Drip Irrigation on Cowpea Yield and Water Use

Many small and marginal farmers do not own their land and generally carry out farming on leased land. Apart from the unpredictable climatic conditions, labour shortage and high labour costs have made farming the last choice for the people of Kerala. The comparative study was conducted to evaluate the performance of low-pressure drip irrigation systems and manual hose irrigation in cowpeas. Irrigation time optimized at 30 minutes provided 500 ml of water per plant. Based on the growth stage, the crop water requirement of vegetables was estimated to be 1 to 2.2 litre/day. To meet this crop water requirement, irrigation was done at 4 times intervals i.e., morning twice and evening twice in such a manner 2.2 litre water was irrigated per plant. Thus, drip irrigation conserved 70% water compared to manual hose irrigation. It was found that drip irrigation gave a 33% higher yield than the yield obtained with the manual drip irrigation system. Overcoming severe drought, 1.18 q/ha-cm water use efficiency was recorded in DIS. Low-pressure DIS increased irrigation efficiency by up to 95% than that of the conventional method of irrigation. It was concluded that 70% water savings were observed for drip irrigation by avoiding the over-wetting of the plot which leads to overrun and water loss.