Long-term Effect of Balanced Fertilizer,Manure and Amendment on Yield Sustainability and Soil Health

摘要

Fertilizer is the key agricultural input for farmers for attaining optimum yield.It has been proved that there is a quantum jump in crop yields and overall production due to fertilizer(50%),thus,prominently contributing to the food basket of our country.Management and balanced use of fertilizers in production of agricultural crops has always been in limelight.While using fertilizers the focus should be on applying them at right time,rate,type and amount in the field by keeping in view the finiteness of natural resources.Indiscriminate use and over-exploitation of natural resources without considering the carrying capacity and non-judicious use of agricultural inputs to achieve optimum production has emerged as great threat to sustain crop productivity and soil quality.Decline in yield and fatigue in soil fertility have been illustrated varyingly under long-term experiments in various cropping systems of different agro-eco-regions in the country.The relationship between soil quality and yield sustainability is very complex.Soil quality is a function of several factors in addition to nutrient management.The parameters,which are sensitive to long-term management practices,are considered as soil quality parameters such as soil organic carbon(SOC),microbial biomass carbon(MBC),soil respiration,dehydrogenase activity and potentially mineralizable nitrogen(PMN).The use of chemical fertilizer is inevitable to increase the productivity in the initial period but there are apprehensions that its long-term use may deteriorate both soil quality and productivity.It was observed that soil organic carbon and the associated nutrients(N,P and K)are critical components of soil quality and yield sustainability.In this paper,a series of long-term field experiments were analysed to assess yield sustainability,soil quality,soil carbon pools,and carbon sequestration under different land use and management practices through basic and applied research.