Mitigating of waterlogging associated problems by the management practices in the rice ecosystem of the Deltaic zone of Tamil Nadu

Abstract

Cauvery Delta is the major rice-growing tract of Tamil Nadu. Continuous waterlogging is inevitable in the delta region due to unexpected heavy rain, leading to stunted crop growth and poor soil conditions. The present study aimed to alleviate the waterlogging-associated problems of stunted growth, crop nutrition deficiency, heavy algal growth and poor soil aeration issues in the heavy clayey soils of deltaic region of Tamil Nadu. Field experiments were laid out with the treatments viz., CuSO4,, (5kg/ha) (T1), Gypsum (500 kg/ha) (T2), Conoweeding+Alternate Wetting and Drying Irrigation(AWDI) (T3), microbial consortia (K and Zn solubilising Bacteria 500 ml/ha) (T4) control (T5) and combination of all (T6) except CuSO4 along with control . The results indicated that the T6 recorded higher plant height (110.2 cm), productive tillers/m2 of 332, filled grains of 118.3 and less chaffy grains of 20.3 nos, high nutrient status of 265 kg/ha of available N,35.4 kg/ha of available P,342 kg/ha of available K, 21.1meq/100 g of Ca,8.2 meq/100 g of Mg and root length and volume. The algal population in terms of dry biomass was reduced to 3.1 (g/m2) from the control group of 11.2 (g/m2) at 15 days after imposing treatment. The per cent increase of 26.0 % grain yield was also recorded in the combination treatment over control. From the present research, combined application of gypsum @500 kg/ha +Cono weeding twice +AWDI and microbial consortia of Zn and K solubilising bacteria @500ml/ha could be recommended for better soil environment and rice production in the delta region.