Soil water balance and response of spring maize (Zea mays) to mulching and differential irrigation in Punjab

A field experiment was conducted during 2007 and 2008 at Ludhiana, to study the effect of paddy straw mulching (0 and 6 t/ha) and irrigation regimes (irrigation water/open pan evaporation ratio 1.2 (I_1.2), 0.9 (I_0.9) and 0.6 (I_0.6)) on performance of spring maize (Zea mays L.) Mulching significantly increased mean seasonal soil-moisture storage and transpiration during both years with overall pooled values of 122.2 and 38.7 mm for soil-moisture storage and 566.5 and 549.2 mm for seasonal transpiration under mulching and no mulching treatments respectively. Mean seasonal soil-moisture storage and transpiration were significantly more under I_1.2 and I_0.9 treatments than I_0.6 during both years. However, during both years mulching significantly reduced mean seasonal soil evaporation compared with no-mulching. Mulching and irrigation significantly increased leaf-area index (LAI) of spring maize. During both seasons, mulching significantly increased grain yield, yield attributes and water-use efficiency (WUE) of spring maize over no-mulching with overall mean grain yield values of 4.96 and 4.22 t/ha and WUE values of 8.76 and 7.64 kg/ha/mm under mulching and no-mulching treatments respectively. Significantly higher grain yield and WUE were also observed under I_1.2 over I_0.6 irrigation treatment.