Improvement of yield of salt tolerant rice genotypes/varieties through gypsum application

Abstract

Salinity intrusion causes problems in the coastal areas of Bangladesh. Climate change creates hazards like cyclone, sea level rise, and storm surge have been increasing the salinity problem in many folds. The coastal region covers about 20% of the country, from where cultivable land more than 30%. Agricultural land uses in these areas are very poor, because of high content of salinity in Rabi season. Already, 830,000 million hectares of land already identified as affected by soil salinity. A field experiment was carried out at saline prone area, Suparishata, Sodor, Satkhira under natural salinity condition during Rabi season 2017-2018. The experiment was carried out with two varieties namely, V1=Binadhan-10, V2=BRRIdhan67 and four levels of gypsum with control G0: 0 kg ha-1, G1: 75 kg ha-1, G2: 150 kg ha-1 and G3: 225 kg ha-1. The experiment was laid out in a split plot design with three replications. The unit plot size was 3m x 4m. The recommended fertilizer doses applied for the experiment were 80 kg N ha-1, 15 kg P ha-1, 50 kg K ha-1. Nitrogen, phosphorus, potassium, sulphur and zinc were supplied from urea, TSP, MoP, gypsum and zinc sulphate monohydrate respectively while urea was applied in three equal splits. Application of silicon had significant effect on plant height, number of effective tiller m-2, length of panicle, total number of spikelets panicle-1, thousand grain weight, number of filled spikelets panicle-1, grain yield straw yield. It seems that the crop responded to the application of gypsum from 75-225 kg ha-1. Overall results suggest that an application of gypsum 225 kg ha-1 along with N, P, K, Zn and Boron might be necessary to ensure satisfactory yield of rice in saline prone area under natural salinity condition.