Amalgamation of Farmers' Bio-priming Knowledge in Integrated Nutrient Management for Sustainable Management of Red Cabbage Soil Under Middle Gangetic Plains, India.

Biotic stress management through bio-priming is a common practice among the farmers of the Indo-Gangetic Plains. However, this indigenous technology is less explored for the sustainable management of soil resources. Therefore, field-based experiments (2016-17 and 2017-18) were conducted in Varanasi to evaluate the combined effect of seedling bio-priming and fertilization on biochemical properties, microbiological properties, and fertility of red cabbage soil at harvest. Based on the farmers' fertilization practice, the recommended dose of fertilizers (RDF) of N:P2O5:K2O were applied @ 120:60:60 kg ha-1. Three compatible bio-agents, viz., Trichoderma harzianum, Pseudomonas fluorescens, and Bacillus subtilis were applied alone and in combination with 75% RDF. The effect of treatment combinations was also analyzed for carbon (C) mineralization by conducting an incubation experiment for 90 days. Bio-priming treatments recorded a higher richness of soil microflora and soil fertility than control and sole application of chemical fertilizers. Application of 75% RDF + T. harzianum + P. fluorescens resulted in highest urease and cellulase activities and soil organic C. Inclusion of dual-species bacterial consortium (P. fluorescens and B. subtilis) in integrated system resulted in highest dehydrogenase activity and available P. These priming agents also exhibited significantly higher CO2 fluxes and C mineralization in our incubation study. A microbial consortium of T. harzianum and B. subtilis increased the microbial biomass C and available K. Although application of triple-species consortium improved C mineralization in laboratory conditions, the positive effects lowered down in field conditions. As a bottom-up approach, customization of bio-priming technology among farmers will help in attaining the UN-Sustainable Development Goals.