Target yield based integrated nutrient management improves greengram productivity nutrient uptake and soil biological quality in an Alfisol

Abstract

Target-yield fertilizer prescriptions are usually validated through crop yield, but their link with rhizosphere biological functioning remains less understood in Alfisol based pulse systems. This short-term field study evaluated whether FYM adjusted STCR-IPNS could improve greengram productivity, nutrient uptake, enzyme activity, microbial response, and PCA derived soil quality index (SQI). Greengram cv. CO 8 was grown in a 12 treatment randomized block design comparing STCR-NPK and FYM adjusted STCR-IPNS at 0.8, 1.0, and 1.2 t ha− 1 yield targets with vermicompost, FYM, RDF, RDF + FYM, farmer practice, and control treatments. STCR-IPNS at the 1.2 t ha− 1 target produced the highest crop response, with plant height, LAI, and SPAD values of 56.63 cm, 3.98, and 50.76, respectively. The treatment achieved 105.8% of the target yield and recorded higher response ratio, benefit: cost ratio, crude protein content, and crude protein yield than the other nutrient management options. Harvest stage N, P and K uptake peaked at 56.01, 16.96 and 41.43 kg ha− 1, respectively. FYM adjusted STCR-IPNS also improved microbial biomass, selected nutrient cycling enzyme activities, and PCA derived SQI. These results indicate that FYM adjusted STCR-IPNS can support greengram productivity while strengthening biological soil quality indicators under the tested Alfisol condition.