Production maximization of rainy season rice (Oryza sativa) through effective use of water and solar radiation under modified system of rice intensification in Assam Kalita R.1,*, Thakuria R.K.2, Medhi B.K.3, Saikia M.4 1Scientist, Stage 3 Agronomy, AICRP for Dryland, B.N. College of Agriculture, Assam Agricultural University, Biswanath Chariali, 784 176 2Principal Scientist (Agronomy), Horticulture Research Station, Assam Agricultural University, Kahikuchi, Guwahati781 017 3Professor Soil Science, Department of Soil Science, Assam Agricultural University, Jorhat, 785 013 4Associate Director, Directorate of Research (Agriculture), Assam Agricultural University, Jorhat, 785 013 *Corresponding author's Email: rekhashreerice@gmail.com, rkalita.2007@gmail.com
Online published on 29 November, 2023. Abstract A field experiment was conducted in a farmers’ field at Nepalikhuti, Golaghat, Assam during the rainy (kharif) season of 2016 and 2017, to find out the effect of different transplanting dates and hill densities of rice (Oryza sativa L.) under system of rice intensification (SRI) which was compared with conventional rice cultivation (CRC). The experiment was designed in factorial split-plot with 2 crop-establishment methods (SRI and CRC) and 3 transplanting dates (26 June, 10 and 25 July) in the main plot; and 4 different hill densities (20 cm × 10 cm, 20 cm × 20 cm, 25 cm × 20 cm and 25 cm × 25 cm) in the subplots and replicated thrice. With an increased grain yield of 5.71 t/ha, SRI-establishment showed a significant yield advantage of 0.83 t/ha coupled with 2.64% more consumptively used water and 1.29 kg/ha-mm more water-use efficiency over CRC. Results showed strong positive correlation (0.95**) between water-use efficiency (WUE) and yield attributes primarily the effective tillers/m2. Regression analysis revealed that irrespective of establishment methods, the consumptive use (CU) of water, accumulated incident photosynthetically active radiation (AIPAR), radiation-use efficiency (RUE) and heat-use efficiency (HUE) greatly influenced the grain yield. However, in SRI, WUE appeared to be an additional key determinant of grain yield. Between 2 establishment methods, SRI was found to be more competent in utilizing water and solar radiation owing to its ideal canopy environment. Top Keywords Conventional rice cultivation, Consumptive use of water, Crop canopy, Radiation-use efficiency, Water-use efficiency. Top |