Effect of continuous FYM and fertilizer applications over nine years utilizing STCR based targeted yield equations on transfer and uptake of micronutrients in an acid Alfisol under a maize-wheat cropping system

Abstract

The present study was conducted to investigate the effect of long-term Soil Test Crop Response (STCR) based nutrient management in regulating soil micronutrient status and optimizing crop productivity under a maize-wheat cropping system in an acid Alfisol. The experiment was initiated during monsoon 2007, consisted of eight treatments viz., control, farmers’ practice, general recommended dose, soil test-based, STCR based targeted yield of 25 (wheat)/30 (maize) and 35 (wheat)/40 (maize) q ha−1 with FYM @ 5 t ha−1 and without FYM. Results revealed that the soil available Fe, Cu, Zn and Mn exhibited depletion in unfertilized plots over initial status. However, the STCR (Integrated Plant Nutrient Supply; IPNS) based targeted yield approach of fertilizer application maintains higher values of DTPA extractable micronutrients in comparisons to all other treatments. After nine continuous years, the highest DTPA- extractable Fe (27.6 mg kg−1), Mn (25.1 mg kg−1), Zn (1.25 mg kg−1) and Cu (0.75 mg kg−1) were recorded in treatment where, FYM was added along with fertilizers for targeted yield of 35 q ha−1. The micronutrient uptake by wheat was higher in STCR (IPNS) treatments. Low SRC values of Zn, Cu, Fe, and Mn indicated that long-term prescription based chemical fertilizers and FYM application can meet the plant nutritional requirement of wheat crop. Hence long-term STCR based integration of FYM (with NPK fertilizers) has an advantage in regulating the supply of micronutrients in soil-plant system and addressing the micronutrient deficiencies.