Interaction of Continuous Fertilization Practices on Tembotrione Degradation in Tropical Soil of India

Abstract:

Laboratory incubation experiment was conducted using the soil collected from Long Term Fertilization (LTF) Experiment plots cultivated with Finger millet-maize cropping sequence. The study was aimed to investigate the influence of different long-term fertilization practices and rates of TMB application on its persistence and degradation behavior in Typic Ustropept soil. The results are showed concentration of TMB residue on day 1, ranged from 0.459 to 0.622, 0.504-1.061, and 0.629-1.348 mg kg-1 across different LTF practices at 60, 120, and 240 g/ha application rates. Higher TMB residue was recorded by 100 % NPK (-S) practice at 60 and 240 g/ha rates and 150 % NPK at 120 g/ha rate and the 100% NPK+ FYM basis recorded lower TMB residue on 1st day of incubation. Tembotrione degradation follows 1st order kinetics of dissipation irrespective of dose and LTF practices. Application of 100%NPK+FYM and omission of K fertilizer practices followed the best fit with 2nd-order kinetics. More than 50 % of the initial tembotrione deposit dissipated on the 15th and 30th at 60 g/ha and at 120,240 g/ha doses respectively irrespective of LTF practices. Tembotrione dissipated with the degradation half-lives of 10.19 to 14.71 days. Half-life of tembotrione ranged from 9.39-22.27 days across the LTF practices and rates of its application. Tembotrione degradation half-life increased with the increased rate of application and the mean HL was calculated to be 9.39-13.72,14.26-20.51 and 18.94-22.27 days respectively at 60, 120 and 240 g/ha. Lowest and highest HL of 14.30 and 19.86 days was observed with 100%NPK(-S) and 100%NPK+FYM respectively and the tembotrione residue was detected in soil up to 60 days irrespective of its application rate. This indicates the existence of interaction between the nutrients management practices and its persistence in soil.