Simplified and Advanced Sentinel-2-Based Precision Nitrogen Management of Wheat

This study compares simplified and advanced precision nitrogen (N) fertilization approaches for winter wheat relying on Sentinel-2 NDVI, grain yield maps, protein content. Five N treatments were compared: (1) a standard rate, calculated by typical balance (Flat-N); (2) variable rate using linear model, adopting proportional strategy (NDVI directly related) (Var-N-dir); (3) compensative inversely (Var-N-inv); (4) the AgroSat model (Var-N-Agrosat); (5) applying Agricolus (Var-N-Agricolus). The was carried out in four fields over two cropping seasons with randomized blocks design. Results indicate that weather remains main factor influencing yield, as it typically happens rainfed crop. No substantial differences crop observed among models within each year experimental location. However, more favorable season, low-input direct (Var-N-dir) resulted best choice, providing higher NUE (nitrogen use efficiency) value. In less results showed better performance of (Var-N-Agricolus Var-N-Agrosat), which limited losses reduced intra-field variability, relevant importance given to increasing frequency abnormal climate phenomena. general, all these VRT allowed reduction excess fertilizers, preservation environment, saving money.