Impact of Organic and Inorganic Sources of Nutrients on Root Architecture, Soil Microbial Biomass and Yield on Low Land Rice Ecosystem

To study the impact of vermicompost, arbuscular mycorrhizae and FYM application on the rice ecosystem at low land, a field experiment was conducted with rice CO(R) 51 at the Department of Soil Science and Agricultural Chemistry, Tamil Nadu Agricultural University in Coimbatore during the winter of 2020. The experiment was framed in Randomized Block Design comprising of 8 treatments viz., Recommended Dose of Fertilizer Soil Test Crop Response approach (T1), RDF 75 % + Farm Yard Manure @ 12.5 t ha-1 (T2), T2 + Seed treatment with Azospirillum and Phosphobacteria + Soil application of AM fungi (T3), RDF 75 % + Vermicompost @ 5 t ha-1 (T4), T4 + Seed treatment with Azospirillum and Phosphobacteria + Soil application of AM fungi (T5), FYM @ 12.5 t ha-1 + Seed treatment with Azospirillum and Phosphobacteria + Soil application of AM fungi (T6), Vermicompost @ 5 t ha-1+ Seed treatment with Azospirillum and Phosphobacteria + Soil application of AM fungi (T7) and Absolute control (T8) and replicated thrice. The maximum microbial population were registered in the plots that received integrated nutrient application of RDF 75 % STCR approach + Vermicompost 5 t ha-1 + seed treatment with Azospirillum and Phosphobacteria + Soil application of AM fungi. Rice root architecture has changed significantly as a result of mycorrhizal inoculation. Mycorrhizal rice plants have more root volume, length, and spread than plants without mycorrhizae. Nutrient retention and availability influenced the presence of microbial-mediated metabolic activities and nutrient transformations during crop growth. Bacteria, fungus, and actinomycetes became less abundant as the crop reached harvest. The population density of mycorrhizospheres that utilize both organic and inorganic fertilizers is higher. The treatments that received Vermicompost or FYM with Vesicular Arbuscular Mycorrhizae and Nitrogen, Phosphorous & Potassium fertilizers obtained the highest yields of rice grain and straw (6740 and 7840 kg ha-1) respectively, and it was clear that the combination of Vermicompost or FYM, VAM and along with NPK fertilizers produced significantly higher yields than their individual applications and absolute control.