Precision nutrient management influences the productivity, nutrients use efficiency, N2O fluxes and soil enzymatic activity in zero-till wheat (Triticum aestivum L.)

The concomitant quandaries of pedospheric health deterioration and diminishing factor productivity constitute the preeminent apprehensions within the realms of crop cultivation, particularly in the densely populated South Asian region. Conventional tillage practices, coupled with indiscriminate fertilizer application in wheat-based rotations, precipitate the degradation of natural resource bases, thereby posing an ominous threat to the rice-wheat cropping system (RWCS) prevalent in the Indo-Gangetic plains (IGP). Nonetheless, the adoption of zero-tillage (ZT) techniques, co-implemented with the judicious dispensation of nutrients through precision nutrient management (PNM), holds the potential to mitigate nutrient losses, curtail environmental ramifications, and augment the overall sustainability of wheat cultivation within the RWCS paradigm. Hence, efforts were made to investigate the impact of PNM on productivity, use efficiency of nutrients (N_tUE), root morphology, soil enzymatic activities, and the N₂O fluxes in ZT-wheat (ZT-W). The treatments were soil test-based NPK (STB-NPK), Nutrients Expert (NE)-based NPK [NE-(LCC_N) NPK], recommended doses of fertilizer (RDF), state recommendation-based NPK, and their nutrients omission treatments, together with consisted of twelve treatments. The result revealed that the PNM practices, like Nutrient Expert + Leaf colour chart (LCC)based NPK[NE-(LCC_N) NPK] co-implemented with ZT significantly (p<0.05) improved the grain yield by (8.05 %), and nutrient use efficiency (NUE) by 58.1 %) but STB-NPK produce ∼ 17.1 % higher grain yield than the RDF. The application of balanced nutrients in ZT-wheat using NE-(LCC_N) NPK reduced the cumulative seasonal N₂O emission by 19.5 % over RDF, whereas, STB-NPK increased the N₂O emission by 26.2 % over RDF, due to the substantial application of N-fertilizer. Similarly, the root length density (RLD), root surface area density (RSAD) and root volume density (RVD) of wheat were found greater under STB-NPK and NE-(LCC_N) NPK than the RDF. Furthermore, the soil enzymatic activity was considerably enhanced due to PNM in the ZT-wheat system compared to the remaining treatments. The STB-NPK, and NE-(LCC_N) NPK, also improved the crop yield, and photo-synthetically active radiation (PAR) through greater leaf area index (LAI) besides other soil-based parameters of wheat. The NE-(LCC_N) NPK notably improves N_tUE, and minimises the GHGs emission than the others. Hence, the nutrient applied through NE-(LCC_N) NPK could enhance the yields, soil properties, and nutrient use efficiencies besides reducing GHGs emissions, thereby, sustaining cereal-based system in the long run.