Effect of Varied Irrigation Scheduling With Level and Times of Nitrogen Application on Crop Water Productivity and Profitability of Wet Rice (Oryza Sativa L.)

Abstract

A field experiment was conducted during kharif season 2022 at Crop Research Centre of Sardar Vallabhbhai Patel University of Agriculture & Technology Meerut (U.P.) India to study the “Effect of varied irrigation scheduling with level and times of nitrogen application on crop water productivity of wet rice (Oryza sativa L.)”. The soil of the experimental field was well-drained, sandy loam in texture, and slightly alkaline. It was low in organic carbon and available nitrogen but medium in phosphorus and potassium. The treatments were; five irrigation scheduling viz.(I1) IW/CPE 0.8 throughout the growth stage, (I2) IW/CPE 0.8 upto panicle initiation stage & thereafter IW/CPE 1.0 upto dough stage, (I3) IW/CPE 0.8 upto panicle stage and thereafter 1.2 upto dough stage, (I4) IW/CPE 1.0 throughout growth stage, (I5) IW/CPE 1.0 upto panicle initiation stage & thereafter IW/CPE 1.2 upto dough stage and six fertilizer management i.e. (N1) 100% RDN : 4 equal splits at 15, 30, 45 & 60 DAT, (N2) 100% RDN : 5 equal splits at 15, 25, 35, 45 & 60 DAT, (N3) 125% RDN : 4 equal splits at 15, 30, 45 & 60 DAT, (N4) 125% RDN : 5 equal splits at 15, 25, 35, 45 & 60 DAT, (N5) 150% RDN : 4 equal splits at 15, 30, 45 & 60 DAT, (N6) 150% RDN : 5 equal splits at 15, 25, 35, 45 & 60 DAT was laid out in split plot design with three replications. Results of the experimental field were revealed that growth parameters viz., plant height, number of tillers, dry matter accumulation, LAI and yield attributes i.e. panicle length, number of panicle, number of grains panicle-1, and 1000-grains weight were significantly maximum in treatment (I5) followed by (I3) and (I4). The grains, straw, and biological yield (47.32; 68.54 and 115.86 q ha-1) and harvest index (40.84%) were found higher under treatment (I5). The maximum water use efficiency (2.77 q ha-1 cm) and water productivity (2.12 kg cm-3) were recorded in (I5). (I5) also recorded highest available NPK (222.7, 15.2 and 184.6 kg ha-1). Treatment (I5) had 30.3% cost of cultivation over conventional tillage (I1). The maximum gross return was recorded into the treatment (I5) followed by (I3) and (I4). Among fertilizer management, treatment (N6) recorded tallest plants (99.4 cm) with highest number of tillers m-2 (248.5 m-2) and dry matter accumulation (1343.1 g m-2), along with the yield attributes i.e. number of panicle, number of grains panicle-1, 1000- grains weight and grain yield were significantly higher in fertilizer management (N6). Among different fertilizer management maximum net return (Rs.96099) was found in nutrient management practice (N6) which is found at par with (N4) (Rs.93237). However, benefit cost ratio was found to be highest (2.41) with (N6) which was closely related with (N4) i.e. (2.40) and lowest with (N1) (2.33). 5 To achieve highest grain and straw yield of rice with higher profit, application of (I5) IW/CPE 1.0 upto panicle initiation stage & thereafter IW/CPE 1.2 upto dough stage and (N6) 150% RDN : 5 equal splits at 15, 25, 35, 45 & 60 DAT are better option.