A simple web-based tool for optimizing nitrogen variable rate application in durum wheat

To help farmers in their decisions, several decision support systems have been developed, although their diffusion is still limited because often perceived as too time- and data-demanding. To overcome these drawbacks, a web-based system that integrates process-based crop simulation models, seasonal forecasts, algorithms for NDVI calculation and N uptake, to provide detailed prescription maps for N variable rate applications (N-VRA) was developed. Through a simple graphical user interface, the user is asked to indicate the location of the field, the cultivar, the sowing date and any application of water and N already supplied. The system automatically retrieves any necessary input to run the crop model to estimate the quantity of N to supply, depending on crop response to N fertilization and expected weather conditions up to the end of the season. Depending on user needs, the system provides outputs ranging from simple tables to detailed N prescription maps that can be directly uploaded on devices mounted on tractors for N-VRA