ABSTRACT
General ad hoc recommendations of fertilizer inputs do not only lead to lower nutrient-use efficiency but also result in poor soil health due to large spatial and temporal variability in soil nutrient-supplying capacity. Across the Indo-Gangetic Plains, the spatial variability in soil nutrient-supplying capacity further differs among contrasting conventional tillage (CT) and conservation agriculture (CA) systems. The success of CA is dependent on the development of component technologies such as water, weed, and nutrient management strategies to support this newly introduced form of agriculture. The nutrient management aspect under CA has remained less focused, even though it has a differential effect on crop productivity, and soil and environmental health. Like other agronomic practices (planting time, spacing, and weeding), suitable modifications to nutrient management practices are required for CA. The chances of success for CA will be limited unless the best nutrient management practices are acknowledged. Therefore, the adoption of CA can gain momentum through effective and efficient implementation of its fourth principle, i.e. nutrient management. In this chapter, the available information on nutrient transformations in soil and nutrient-use efficiency under CA, as well as opportunities for using precision nutrient management tools for efficient fertilizer nutrient usage based on scientific evidence are presented.
