Leaf Color Chart for Sustainable Nitrogen Utilization - Concept and Ways Forward.

Nitrogen (N) is one of the most crucial elements for crop yields. N management is incredibly important because it's a major component of crop productivity. It is challenging to control due to the large field variability of the innate soil N and the differences in crop demand at various crop growth stages. Additionally, N's partial factor production is deteriorating day by day. Furthermore, crop, cultivar, and environmental factors affect how much N is needed. Therefore, crop production depends heavily on applying N at the right rate for the crop's needs. Precision N management increases N use efficiency while reducing N loss from runoff, ammonia volatilization, and leaching. By providing N during crucial growth phases, real-time N management increases use efficiency by applying N based on need at the appropriate time and amount. One aspect of real-time N management is the application of the leaf color chart (LCC). The LCC is a relatively basic, low-cost, portable, and user-friendly gadget that contrasts the color of the leaf with the device's color hues. Because farmers typically prefer dark-colored leaves, they apply N regardless of need, which poses serious risks to the ecosystem and contaminates the surface and groundwater. The sustainability of output is threatened by the declining soil health caused by increased fertilizer application. Therefore, for small and marginal farmers, employing a leaf color chart for site-specific N management is a more practical solution. [ABSTRACT FROM AUTHOR]