Effect of Different Cropping Systems on Distribution of DTPA-Extractable and Total Zn, Cu, Fe and Mn Fraction in Alluvial Soils of Punjab

摘要

A field experiment was in progress since 2000. The objective of the investigation was to study the long term effect of different cropping systems on physico-chemical properties of soil and distribution of DTPA and total Zn, Gu, Fe and Mn after 8 yearsof continuous cropping. The experiment comprised ten treatments combinations. Among different cropping systems, toria, gobhi sarsonj groundnut were included to increase the influx of DTPA and total Zn, Cu, Fe and Mn fractions. Besides improvement in DTPA-extractable Zn, Cu, Fe and Mn content, these crops showed significant improvement in the soil nutrient status with the addition of biomass by toria, gobhi sarson, groundnut and cotton crops. Rice-wheat system reported the highest content of DTPA-Zn (5.86 mg/kg), Fe (13.96 mg/kg) and Mn (5.08 mg/kg) followed by maize-wheat, maize-wheat-summer mungbean, maize-potato-summer mungbean and maize-potatoonion cropping systems. Sarson based cropping systems viz. cotton-African sarsori, cotton-gobhi sarson transplanted and summer groundnut-toria + gobhi sarson reported the highest content of DTPA-Zn, Fe and Mn followed by groundnut-potato-pearlmillet system. Our results evinced that sarson and groundnut based cropping systems reported the higher content of total Zn, Cu, Fe and Mn indicating that total fractions of micronutrients can be transferred to their corresponding readily available forms. The results of our study further reported that the inclusion of cotton, gobhi sarson, african sarson, toria and groundnut in the cropping systems could help in mobilization of DTPA Zn, Cu, Fe and Mn and build their concentrations in the soil to sustain the agricultural systems.