Rice straw compost: a sustainable residue recycling solution for soil health and productivity enhancement in the rice-wheat cropping system

The rice-wheat cropping system is the predominant crop rotation within the Indo-Gangetic Plain (IGP).A pressing concern in the region is the escalating issue of burning crop residues, coupled with the need to reduce the reliance on costly fertilizer inputs.A promising avenue to address both challenges lies in implementing integrated nutrient management (INM).An INM experiment was started at the Central Soil Salinity Research Institute (CSSRI) in Karnal to explore this solution in 2015.The experiment aimed to evaluate the effectiveness of eight distinct INM modules, namely: RS-F100, involving the in situ retention and incorporation of one-third of rice stubble along with 100% of the recommended fertilizers; RS-F150, similar to RS-F100 but with 150% of recommended fertilizers; WS-F100 and WS-F150, which same as the previous modules but pertain to wheat stubble; PSC-F50, utilizing 5 tons per hectare of Paddy Straw Compost (PSC) along with only 50% of recommended fertilizers; PSC+FYM-F50, combining 5 tons per hectare of PSC with an equal amount of Farmyard Manure (FYM), along with 50% of recommended fertilizers; GM+FYM-F50, involving Green Manuring with Sesbania aculeata, 5 tons per hectare of FYM, and 50% of recommended fertilizers; GM+PSC-F50, akin to the previous module but incorporating PSC instead of FYM.These modules were compared against F, representing 100% recommended fertilizer application, and O, signifying no fertilizer application (absolute control).The research finding revealed that grain yields and straw increased significantly under GM-PSC-F50 and GM-FYM-F50 INM modules.These INM modules make it possible to reduce chemical fertilizer usage by 50%.In cereal residuebased INM, including rice residue with 100% fertilizer led to a marginal yield reduction.However, this decrease could be effectively countered by adopting a 150% fertilizer application.The soil available N, P, K, and organic carbon was significantly improved under different INM modules.In conclusion, the promising INM modules are green manuring with Sesbania aculeata + Paddy straw compost, PSC @ 5 t ha -1 + only 50 % of recommended fertilizers (GM-PSC-F50), 1/3 rd in situ wheat stubble retention and incorporation + 100 % recommended fertilizers (WS-F100), and 1/3 rd rice stubble in situ retention and incorporation + 150 % recommended fertilizers (RS-F150).