Effect of nutrient and weed management on crop productivity and soil microbial properties in aerobic rice (Oryza sativa)

A field experiment was conducted during rainy (kharif) seasons of 2020 and 2021 at the research farm of ICARIndian Agricultural Research Institute, New Delhi to study the effect of nutrient and weed management on crop productivity and soil microbial properties in aerobic rice (Oryza sativa L.). Experiment was conducted in factorial randomized complete block design and replicated thrice. Nutrient management factor comprised 3 levels, viz. Control, 100% and 75% RDF + Biofertilizer (BF) consortia; and weed management factor comprised 5 levels, viz. Weedy check, Pyrazosulfuran + Bispyribac + Almix, Bispyribac + mulch, Sesbania + hand weeding (HW) and weed free check. Significantly higher plant growth and grain yield (4.2 and 4.4 t/ha) and biological yield (11.6 and 11.6 t/ha) of rice were recorded with 100% RDF but these parameters were at par with 75% RDF+ BF consortia. However, soil microbial biomass carbon, nitrogen as well as soil microbial biomass phosphorus were recorded significantly higher with 75% RDF + BF. In weed management treatments significantly higher plant height, no. of tillers, grain yield and biological yield were recorded under weed free check over weedy check and Sesbania + HW but these were recorded at par with Pyrazosulfuran + Bispyribac + almix and Bispyribac + mulch. Soil microbial biomass was significantly higher with Sesbania + HW over weedy check, Pyrazosulfuran + Bispyribac + Almix and weed free check but were at par with Bispyribac + mulch. Hence, 75 % RDF + Biofertilizer consortia along with weed management through Bispyribac at 25 DAS + organic mulch (3 t/ha) may be recommended for enhancing crop productivity and soil microbial properties in aerobic rice.