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In order to address the scarcity of phosphorus nutrient reserves and the variations usually observed in the P nutrient storage in soils, a long-term experiment was targeted to assess the impact of integrated fertilizer schedule on soil phosphorus pools and ecophysiological ratios of phosphorus element. P-related soil enzymes like acid phosphatase activity and alkaline phosphatase activity were improved by 6.53–15.93% and 6.14–11.41%, respectively, over the recommended dose of fertilization. Addition of FYM recorded highest DHA (45.24 µg TPF released g−1dry soil h−1) followed by wheat straw (41.25 µg TPF released g−1dry soil h−1) and green manure (38.98 µg TPF released g−1dry soil h−1). Integrated fertilizer schedule improved the microbial biomass phosphorus content by 8.97–29.72% as compared to 100% recommended dose through mineral fertilizer. In the integrated system, only 5–7% of the organic phosphorus was ascribed to microbial biomass, reflecting the accumulation of organic P forms. Higher ratio of DHA (0.20) and pyrophosphatase (0.23) to microbial C in integrated treatments confirmed that the enzyme activities were from extracellular enzymes released by microorganisms. The lower ratios of alkaline or acid phosphatase to pyrophosphatase indicate domination of phosphomonoesters in the P pools. These ratios are important to understand the P availability in soil systems especially under the integrated fertilization schedule.

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.