Simulation of Nutrient Requirement and Use Efficiency in Irrigated Wheat Using the QUEFTS Model.
Debtanu Maiti, Dept of Agricultural Chemistry and Soil Science, Faculty of Agriculture, Bidhan Chandra Krishi Viswavidyalaya, WB, Room No - 32, Indian Agricultural Research Institute, Pusa, New Delhi, 110012, India
Crop modelling can provide us a vast amount of real time information about fertilizer dose to achieve the target yield, crop conditions etc. Nutrient use efficiency in wheat is low because of conventional blanket and imbalanced fertilizer use. Estimation of fertilizer requirements based on quantitative approaches can assist in improving yields and nutrient use efficiency. Field experiments were conducted in 20 sites in eastern India to assess the soil supply, requirement and internal efficiency of N, P, K and Zn in wheat. The data were used to calibrate the QUEFTS (QUantitative Evaluation of the Fertility of Tropical Soils) model for site-specific, balanced fertilizer recommendations. The parameters of maximum accumulation (a) and maximum dilution (d) in wheat were calculated for N (35, 100), P (129, 738), K (17, 56) and Zn (21502, 140244). Grain yield of wheat showed good correlation with N (R2=0.937**), P (R2=0.901**) and K uptake (R2=0.801**). The NPK ratio to produce 1 ton grain yield of wheat was derived to be 4.9:1.0:8.9. The relationships between chemical properties and nutrient supplying capacity of soils were also established. The model was validated using the data of other 4 experiments. Observed yields with different amounts of N, P, K and Zn were in good agreement with the predicted values suggesting that the validated QUEFTS model can be used for site-specific nutrient management in wheat. Additional keywords: fertilizer requirements, target yield, QUEFTS, wheat. Debtanu Maiti1*, D. K. Das1 and H. Pathak2 1Department of Agricultural Chemistry and Soil Science, Faculty of Agriculture, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia-741252, West Bengal, India. 2Unit of Simulation and Informatics, Indian Agricultural Research Institute, Pusa, New Delhi-110012, India.