Response of Transplanted Rice to Seedling Root-dip in Phosphorus and Biofertilizer Slurry in Acid Soils of North East India- A Participatory Assessment in Farmers’ Field

Background: Rice production is mainly constrained by low P-use efficiency (PUE) and P-recovery efficiency (PRE) in acid soils of the North East hill region of India. Efficient P fertilizer management strategies for rice production is very essential to achieve higher yield per unit of P fertilizer applied. Rhizosphere-based P management in wetland rice is considered as an efficient strategy to minimize the quantity of applied P to obtain a profitable yield. Methods: Seedling root dipping in P slurry technique in farmers’ field condition was studied in comparison to the conventional methods of application of recommended dose of fertilizer (RDF) and the integrated nutrient management (INM) practices to identify a suitable cost effective method of application of phosphatic fertilizer for the acid soils of this hill region of North East India. Result: The highest plant height, maximum number of effective tillers and root biomass were recorded in SSP root dip+Phosphate Solubilizing Bacteria (PSB) followed by INM practices. P root dip had greater root biomass (4.36 g plant-1) which was significantly higher than RDF (3.82 g plant-1). Root dip application showed higher yields (5.80 t ha-1), compared with INM (5.53 t ha-1) and RDF (5.46 t ha-1) and control (4.25 t ha-1). The result of the present study demonstrated that P-dipping can achieve high applied P use efficiency (1193.42) in transplanted rice compared to conventional incorporation of P (625.43). Thus, P-dipping is a potential strategy to overcome low applied P use efficiency in high P-fixing soils and hence reduces the need for excess P application.