Effect of rice straw mulching and irrigation intervals on sugarcane (Saccharum officinarum) yield and water productivity in sub-tropics of punjab

Six on farm trials at different farmer's field locations characterized by sub-tropical climate were conducted to investigate the effect of rice straw mulching dressed @ 4.0 t/ha in sugarcane, by scheduling irrigation at weekly and fortnightly interval on cane yield and water productivity. Average sugarcane yield increased significantly (P=0.05) by 7.7% with rice straw mulching in weekly irrigated plots. In consonance, sugarcane yield increase from fortnightly irrigated mulched plots was also significant (P=0.05) (7.9%) over un-mulched plots. On an average, sugarcane crop received 26 irrigations in weekly irrigated plots that accounts for about 87.7% higher irrigation water than from plots irrigated at fortnightly interval receiving only 14 irrigations. Crop water productivity in rice straw mulched plots irrigated at weekly interval, varied from 132.3 to 153.1 kg cane/ha/cm of water applied. In comparison, water productivity in un-mulched plots receiving irrigation at same interval varied from 124.9 to 142.7 kg cane/ha/cm of water applied. However, water productivity in mulched sugarcane plots irrigated at fortnightly interval varied from. 233.3 to 299.5 kg cane/ha/em and from 205.7 to 285.1 kgcanc/ha/cm of applied water in mulched and un-mulched plots, respectively. Statistical non-significant (P=0.05) yield difference from un-mulched plots irrigated at weekly interval and rice straw mulched plots irrigated at fortnightly interval revealed substantial water saving with mulching without any significant variation in crop yield. Thus, it can be concluded that rice straw mulching in sugarcane results in significantly (P=0.05) higher sugarcane yield and enhanced water productivity besides saving of irrigation water.