assessment of soil quality indicators in rice soils of tamil nadu

Abstract

The present investigation entitled Assessment of Soil Quality Indicators in newlineRice soils of Tamil Nadu was carried out during 2018 with the objectives: to newlineassess the soil physico-chemical and biological quality parameters in rice soils of newlineTamil Nadu, to compare soil quality indexing methods viz., Principal component newlineanalysis, Minimum data set and Indicator scoring method and to develop soil quality newlineindices for formulating soil and crop management strategies. newlineTo fulfil these objectives a total of 180 soil samples were collected randomly newlinefrom intensive rice cultivating districts, Thanjavur, Thiruvarur, Nagapattinam, Cuddalore, newlineVilllupuram, Thiruvannnamalai and Ramanathapuram district and TNAU research newlinestations located in these respective districts. Soil samples were collected from newlinerepresentative sites of the intensive rice growing regions in each district. newlineTo study the impact of nutrient / crop management practices on soil quality newlinesamples were collected in TNAU research stations in each district under study. Soil newlinesamples were analysed for physical, chemical and biological properties by adopting newlinestandard procedure. A total of 20 indicators were considered for soil quality newlineassessment including the soil physical indicators (sand, silt, clay, texture, bulk density, newlinewater holding capacity and MWD); chemical indicators (pH, electrical conductivity (EC), newlineCEC, organic carbon (OC), soil available N, P, K, and total N and available micronutrient newline(Fe, Zn, and B) contents . Biological properties viz., microbial biomass carbon and newlinenitrogen (MBC and MBN), potentially mineralizable nitrogen (PMN) and soil newlinerespiration and dehydrogenease activity were determined. newlineBetween the nutrient management practices organic farming practice registered newlinelow sand content in Thanjavur and Thiruvarur districts. Among the rice cultivation newlinemethods followed in Nagapattinam and Cuddalore districts, higher sand content was newlinerecorded in aerobic and mechanical rice farming methods. Conventional and mechanical newlinerice farming methods registered high sand conte