SUPPLEMENTAL IRRIGATION AND MANURING TO ALLEVIATE THE ADVERSE EFFECT OF TERMINAL DROUGHT STRESS ON TRANSPLANTED AMAN RICE

Abstract

Due to changed climatic situation, rainfall pattern is being changed day by day. About 90% of the total rainfall occurs during April to October. Abrupt ending of monsoon in September can create severe water stress in T. Aman season. Therefore, a study was designed to assess and find out effect of supplemental irrigation on growth and yield for sustainable rice production in aman season. It also evaluated the efficacy of poultry compost, cowdung, vermi compost and biochar in alleviating the adverse effect of terminal drought stress on T. aman rice. The experiment was performed in the field and laboratory of the Department of Crop Physiology and Ecology, HSTU, Dinajpur, during July to December 2022. The experiment was laid out in Randomized Complete Block Design with three replications. Seven sets of treatments were used in this experiment. The treatments are as follows: T1 = recommended dose of fertilizer (RDF)+Rainfed, T2 = RDF+ Rainfed+ one supplemental irrigation, T3 = RDF+ Rainfed+ two supplemental irrigation, T4 = RDF + Rainfed+ poultry Compost (10 tha-1), T5 = RDF + Rainfed + cowdung (10 tha-1), T6 = RDF +Rainfed+ Vermi compost, T7 = RDF + Rainfed + Biochar (10 tha-1). Rice variety BRRI dhan 52 was used as planting material. The experimental plot was divided into 21unit plots of 2 m × 2 m sizes. The distance between line to line was 25 cm and hill to hill was 15 cm. Data were collected on growth parameters like plant height, tiller number hill-1, leaf number hill-1, root dry weight hill-1 (g), shoot dry weight hill-1 (g) and SPAD values at 40, 55 and 70 days after transplanting (DAT). Yield contributing parameters such as Plant height, panicle length, tillers hill-1, panicles hill-1, grains panicle-1, thousand grains weight, grain yield hill-1, yield m-2 were recorded at harvest. All the growth parameters influenced by the treatment combination, T4 @ RDF + Rainfed + poultry compost (10 t ha-1), T5 @ RDF + Rainfed + cowdung (10 t ha-1), performed better than other treatments. Yield contributing characters such as panicle hill-1, panicle length, total Yield contributing characters such as panicle hill-1, panicle length, total spikelet panicle-1, grain weight panicle-1, grain yield hill-1, produced significantly. The highest grain yield m-2 (769.33g) was obtained through additional 10 tha-1 poultry compost applied (T4), While the lowest grain yield m-2 (626.67g) was recorded when additional 10 t ha-1 vermi compost applied (T6). The results of the present study indicated that supplemental irrigation and combination of manure treatments was influence to alleviate the adverse effect of drought stress condition in T. aman rice BRRI dhan 52 and One supplemental irrigation was enough for sustaining yield in T. aman under terminal drought stress condition.