Integrated Nutrient Management in Coconut (Cocos nucifera L.): an Assessment of Soil Chemical and Biological Parameters Under Subtropical Humid Climate

Purpose Agricultural waste recycling is an integral part of integrated nutrient management (INM) which is essential to maintain soil health, yield sustainability and also safe guard the natural resources for a longer period. Coconut plantation generates a huge quantity of waste biomass every year and recycling of those biomass through INM modules could be an eco-friendly approach to meet our needs. Methods Four different waste recycling regimes viz. no recycling, 25% recycling, 50% recycling and 100% recycling with various organic wastes were imposed in a coconut plantation. Soil properties, soil enzymatic activities, organic carbon and available nutrient content were analysed for two consecutive years viz. 2018–2019 and 2019–2020 to assess the plausibility of organic waste recycling in the INM module. Results Under 100% organic recycling, soil organic carbon content in the surface layer was estimated 5 times higher than the application of a recommended dose of inorganic fertilizers. Available nitrogen, phosphorus and potassium were lower under the INM schedule reflecting their nutrient storage capacity in organic forms. DTPA extractable Fe, Zn, Mn and Cu content also followed the same pattern. Soil enzymatic activities were improved under the INM schedule (4–47% in DHA, 2–27% in urease, 7–49% in ß-glucosidase, 3–73% in acid phosphatase, 4–71% in alkaline phosphatase and 4–52% in FDA) across all the soil depths. Conclusion Recycling of organic waste improved the enzyme activities related to nutrient cycling and maintains a favourable soil biological condition for nutrient release. This study opens an avenue for organic farming under coconut plantation in subtropical humid regions.