10. TREND OF NITROGEN INFLOW TO SOIL IN TAMIL NADU by R. PARAMASIVAM1, P. PARAMASIVAM2 AND R. BALASUBRAMANIAN3

Abstract

The present study examined the trend of nitrogen inflow from various source across districts of Tamil Nadu since 1990s. This study used both cross section and time series data from 1990-91 to 2012-13. Inorganic fertilizers were the prime source of nitrogen inflow followed by livestock manure, legumes and green manure. During 1990-99 to 2000-09, growth rate of nitrogen inflow from inorganic fertilizers significantly declined almost all agrarian based districts. Trichy, Madurai, Ramnad, Virudhunagar, Sivagangai, Tirunelveli and Thoothukudi districts accounted positive growth rate of nitrogen inflow from inorganic fertilizers. Trend of livestock manure started to increases almost all districts. Growth rate of nitrogen inflow from livestock manure was positive and larger in Sivagangai and Tirunelveli in all periods whereas lowest growth rate observed in Dharmapuri, Vellore and Dharmapuri districts. Over uses of inorganic fertilizers and competitive uses of cow dung manure would possibly develop an imbalance nitrogen status to soil and negatively led sustainable agriculture. It is suggested that optimal use of inorganic fertilizer and higher amount of cow manures inflow to soil may support for sustainable soil use.
KEY WORD: Livestock manure, Fertilizers, Nitrogen, Sustainable agriculture.