Long-term impact of legume-inclusive diversification and nutrient management practices on phosphorus dynamics in alkaline Fluvisol

• Published in: Scientific reports Vol. 14; no. 1; p. 65
• Main Authors: Dutta, Asik, Hazra, K. K., Nath, C. P., Kumar, N., Singh, S. S., Praharaj, C. S.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 02.01.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 704/158/2456; 704/172/169; 704/47/4112; Agrochemicals; Alkaline soils; Bioavailability; Biomass; Cereal crops; Correlation analysis; Crop production; Crops; Fertilizers; Humanities and Social Sciences; Legumes; multidisciplinary; Nutrient dynamics; Phosphorus; Rice; Science; Science (multidisciplinary); Soil depth; Soil dynamics; Sustainability management; Wheat
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-49616-x

An insight into the dynamics of soil phosphorus (P) pools with long-term cropping/management practices would help in designing efficient and sustainable management module(s). The study aimed to investigate the long-term impact of diversified rice-based rotations and variable nutrient management practices on the dynamic composition of P pools and their influence on systems’ base-crop productivity in an alkaline soil of Indo-Gangetic plain ( Fluvisol ). Treatments consisted of four rotations [rice–wheat (R–W), rice–wheat–mungbean (R–W–Mb), rice–wheat–rice–chickpea (R–W–R–C), rice–chickpea (R–C)] each with three nutrient treatments [control (CT), integrated nutrient management (INM), sole-chemical fertilizers (CF)]. Notably, R–C exhibited higher levels of bioavailable-P (soluble-P, Ca 2 -P, labile-Po), particularly in subsurface soil depth (0.2–0.4 m) compared to other rotations. Likewise, the inclusion of chickpea every alternate year (R–W–R–C) resulted in higher Ca 2 -P (40%), labile-Pi (15%), labile-Po (11%), and moderately labile Po (8%) compared to R–W rotation demonstrating an increased significance of chickpea in maintaining a favorable soil P regime in alkaline soil. Both R–C and R–W–R–C reduced the surface-to-subsurface depth ratio (SSBR) of soluble-P and Ca 2 -P while increasing the ratio for microbial biomass P. Even with a suboptimal fertilizer-P rate, INM significantly increased soluble-P (4–33%), labile-Po (13–17%), microbial biomass P (10–26%), moderately labile-Po (4–17%) compared to CF and exhibited higher SSBR values. Correlation analysis demonstrated the substantial influence of very-labile carbon, microbial and phosphatase activities on P availability. The treatment-induced changes in labile-P pools significantly influenced rice (base-crop) yields. In conclusion, chickpea-inclusive diversification and INM could be a sustainable approach to enhance P bioavailability and crop productivity in tropical rice soils.