ABSTRACT
The site-specific nutrient management (SSNM) approaches emphasizes on feeding rice and wheat with nutrients as and when needed to achieve high yields while optimizing use of nutrients from indigenous sources. The plant-based SSNM tools such as leaf colour chart, chlorophyll meter and optical sensors are becoming known to farm managers and the these fertilizer management strategies are being included in the package of practices given to farmers in different states in India. Guidelines for distribution of fertilizer N during the crop growth season constitute an important aspect of the plant-based SSNM approach. Site-specific nutrient management requires little in the way of credit for financing or complex coordination among farmers. Augmenting the nitrogen supply to crops through biological nitrogen fixation is a viable option for resource-poor farmers of the humid tropics and must be exploited to its fullest potential.
