Nitrogen Management Paradigm in Horticulture Systems in India

Abstract

Nitrogen (N) is the mineral nutrient that crops require in the greatest amount. It has more influence on crop growth, production, and quality than any other nutrient. Nitrogen is as much essential to plant growth as it is a potential environmental pollutant. Nitrogen applied to a field but not removed in harvested products is at risk of eventually leaving the field in gaseous or liquid form. The N content of horticulture produces is generally lower than those of agricultural crops. As a result, the proportion of fertilizer N disseminated out of the systems through fruits and vegetables is low. Hence under high intensive horticulture systems, amount of free N available for loss through leaching, denitrification, erosion, etc. is huge. Increasing the efficiency of fertilizer N use can be accomplished by modifying soil and crop management practices to reflect the transitory nature of soil N. Timing and placement of fertilizer application to coincide with peak periods of utilization is foremost in importance as an aid in this venture. Several studies have documented the benefits of judicious use of chemical fertilizers, organic manures, and microbial inoculants in improving N use efficiency and enhancing crop productivity. It minimizes the risk of causing pollution by loss of N through runoff, leaching, emissions to the air, or other mechanisms. In this chapter, an attempt has been made to review various issues and approaches/practices that reduce N losses, thus making them environmentally friendly.