Integrated nutrient management for sustainable soil and tea productivity

Abstract

Field experiments were conducted to standardize the nutrient supply by integrated nutrient management (INM) approach in young and as well as mature tea. Quality organic manure (QM), consortium of biofertilizer (BF) consisting of Azotobacter, Azospirilum and phosphate solubilising bacteria (PSB) and conventional inorganic fertilizers were applied in different combinations. During first two years of observations the results indicated that soil properties namely organic carbon (org C), pH, bulk density (BD) and water stable aggregates (WSA) under all integrated treatments were at par and did not show any significant difference between treatments including 100% recommended doses of fertiliser (RDF) in mature tea field. However, from the 3rd year onwards, 25% replacement of RDF by either 6 tonnes QM or consortium of BF mixed with 1 tonne QM maintained significantly higher org C, WSA, available phosphate (av. P) and improved soil microbial carbon (MBC) over RDF. These treatments also significantly and consistently increased the yield of mature tea compared to RDF. Similar results were also recorded in young tea where 75% of RDF (YTD) in combination with consortium of BF (Azotobacter, Azospirilum and PSB/ phosphate solubilising fungus) produced significantly higher growth and yield over 100 % YTD (RDF). Effect of phosphate solubilising fungus (PSF) was found to be more promising.

Keywords: INM, quality organic manure, biofertilizer, soil properties, yield