Simulation of fertilizer requirement for irrigated wheat in Eastern India using the QUEFTS model

Debtanu Maiti,H Pathak,D.K Das

doi:10.1100/tsw.2006.43

Abstract

Crop modeling can provide us with information about fertilizer dose to achieve the target yield, crop conditions, etc. Due to conventional and imbalanced fertilizer application, nutrient use efficiency in wheat is low. Estimation of fertilizer requirements based on quantitative approaches can assist in improving yields and nutrient use efficiency. Field experiments were conducted at 20 sites in eastern India (Nadia district of West Bengal) 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 statistically significant correlation with N (R2 = 0.937**), P (R2 = 0.901**), and K uptake (R2 = 0.801**). The NPK ratio to produce 1 tonne grain yield of wheat was calculated 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 from four other 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 of wheat.

Highlights

Due to conventional blanket and imbalanced fertilizer application, nutrient use efficiency in wheat is low
The second trial was conducted for site-specific nutrient management (SSNM) to compare observed and simulated values of yield and nutrient uptake where the fertilizer requirement of different nutrients were fixed based on the QUEFTS model to achieve the target yields of 5 and 6 t/ha
Grain yield ranged from 1.50–5.50 t/ha, with N-application rates varying from 0–100 kg/ha across the sites (Table 1)

Summary

Introduction

Due to conventional blanket and imbalanced fertilizer application, nutrient use efficiency in wheat is low. The site-specific nutrient management (SSNM) strategies that include crop nutrient requirement, indigenous nutrient supply, and recovery efficiency of applied fertilizer should be used to increase yield of wheat. Estimates of indigenous nutrient supply, nutrient requirements, internal efficiency, recovery efficiency of nutrients, and subsequent fertilizer recommendations for wheat (Triticum aestivum L.) have been made through field experiments at several researcher sites. These estimates can only partly be extrapolated to farmers’ fields because of the much broader range of soil, climatic, and management. Estimates of fertilizer requirements should be based on more generic, quantitative approaches, such as the use of simulation models.

Methods

Results

Discussion

Conclusion