Nitrogen fertilizer losses from rice soils and control of environmental pollution problems

Nitrogen (N) requirements of rice crop are met from both the soil and fertilizers. Because of acute N deficiency in most rice soils, fertilizer N must be applied to meet the crop demand. N fertilizer applied to rice crops is partially lost through different mechanisms, including ammonia volatilization, denitrification, and leaching. These losses may cause environmental problems such as polluting the atmosphere, aquatic systems, and groundwater. These problems cannot be alleviated completely. However, they can be reduced a considerable extent by various techniques. Research has been conducted around the world to minimize N fertilizer losses. This paper reviews this information on N fertilizer losses, indicating management practices for minimizing these losses from the soil-water system.