ROLE OF CROP DIVERSIFICATION AND INTEGRATED NUTRIENT MANAGEMENT IN RESILIENCE OF SOIL FERTILITY UNDER RICE-WHEAT CROPPING SYSTEM

摘要

A field study conducted for two crop cycles of five cropping systems supplied wilt six nutrient combinations at the Indian Agricultural Research Institute, New Delhi indicated that the cropping syslems having a legume increased organic C content overinitial level by 0.02-0.05%, available N by 3.5- 14.1 kg ha~(-1), whereas the rice-wheat cropping system resulted in a reduction En organic C and available N over initial level by 0.05% and 1.5 kg ha~(-1), respectively after 2 years of study. Rice-potato-mungbean cropping system resulted in a negative balance of available P and rice-clover cropping system had a negative balance of both available P and available K content in soil and thus call for adequate P and K fertilization. Application of P and K helped in building up their content in soil; NPK + FYM showed the highest increase in organic C, available N, available P and available K conlenl in soil. These results suggest the inclusion of a legume in a cropping system for maintaining organic C and available N in soil and adequate P and K fertilization for arresting the depletion of available P und K content in soil. Integrated nutrient management is one of the best methods for resilience of soil fertility under rice-wheat cropping system.