Soil Test Crop Response-Based Fertilizer Application Improves Soil Fertility and Wheat (<i>Triticum Aestivum L</i>.) Productivity Grown After Direct-Seeded Rice in Mollisols of Northern India

Soil Test Crop Response (STCR) based fertilizer recommendation aids in precise fertilizer application, which is tailored to soil and crop needs, thereby increasing yield and saving inputs. Moreover, validation of STCR approach ensures these recommendations are reliable, promoting sustainable farming practices. Thus, field experiments were conducted during 2017 to 2019 with the objectives to develop and validate STCR-based fertilizer prescription equations for targeted yields of wheat grown after direct-seeded rice under both chemical fertilizer alone and integrated plant nutrient supply (IPNS) conditions. Results revealed that 2.16 kg, 0.447 kg, and 2.29 kg of N, P, and K was required to produce 1 Mg of wheat grain, respectively. The contributions of N, P, and K from various sources were, 12.02%, 14.82%, and 11.00% from soil, 12.83%, 19.48%, and 35.07% from applied farmyard manure (FYM), 53.54%, 60.24%, and 231.84% from fertilizers, and 60.26%, 70.66%, and 275.41% from fertilizers + FYM, respectively. The STCR approach, whether applied with or without FYM, significantly enhanced grain yield for both target yields of 4.0 Mg ha⁻¹ and 4.5 Mg ha⁻¹. The increments were to the tune of 28.6% and 39.3% with inorganic approach, and 21.1% to 31.1% with the integrated approach, compared to the general recommended dose (GRD). Additionally, the STCR method exhibited higher uptake of NPK and its use efficiencies, as well as better profitability than the GRD. Thus, the STCR-targeted yield approach, whether inorganic or integrated, has the potential to improve yield, economic returns, and nutrient use efficiency for wheat crops grown in Mollisols of Northern India.