Evaluation of N-Carb in Rice Soils

Soil-based biostimulants are increasingly being evaluated as sustainable inputs for improving soil health,nutrient-use efficiency, and crop productivity. The present study was conducted to evaluate the effectivenessof N-Carb, an organic carbon- and nitrogen-based product, in improving growth, yield, nutrient uptake,and selected physiological indicators of rice. A field experiment was conducted during the kharif seasonof 2022 at the ICAR-Indian Institute of Rice Research farm, Hyderabad, using rice variety DRR Dhan 48. Theexperiment was laid out in a randomized block design with three replications and four treatments consistingof recommended dose of fertilizers (RDF) alone and RDF combined with N-Carb applied at different cropgrowth stages. N-Carb was applied at a concentration of 6.5 mL L−1 according to the respective treatmentschedules. The initial soil was a slightly alkaline deep black clayey Vertisol with low available nitrogen,medium available phosphorus, and high available potassium. Application of N-Carb along with RDF generallyimproved plant growth, effective tillering, grain yield, and nutrient uptake compared with RDF alone. Thehighest grain yield (6.28 t ha−1 ) was recorded with three applications of N-Carb at basal, active tillering, andpanicle initiation stages, followed closely by application at basal and active tillering stages (6.26 t ha−1).N-Carb application also increased SPAD meter readings and NDVI values and improved post-harvest soilnitrogen status. The results indicate that N-Carb has potential as a supplementary input for improving ricegrowth and productivity when integrated with recommended fertilizer practices.