Nitrogen fertilizer is essential for crop production; however, its inefficient use leads to economic losses and environmental degradation. This study evaluates a simplified NDVI-based algorithm for variable-rate nitrogen fertilization, assessing its agronomic and economic performance with specific attention to potential applicability in Mediterranean and Palestinian smallholder farming systems. Field experiments were conducted over two growing seasons (2020-2022) at three locations in the Krasnodar region of Russia, covering winter wheat and barley across approximately 450 hectares. A simple algorithm was evaluated, calculating variable nitrogen rates for each management zone based on the ratio between zone NDVI and field average NDVI, with clamping limits (0.7-1.3 × uniform rate) for agronomic safety. Results demonstrated that variable-rate application reduced nitrogen use by 14 kg/ha on average (12% reduction) compared to uniform application, with no statistically significant yield penalty (p > 0.05 for all sites). Partial Factor Productivity (PFP) increased significantly from 75.9 kg yield/kg N to 87.0 kg yield/kg N (+14.6%, p = 0.01). NDVI variability across management zones decreased from 22% to 9%, indicating improved spatial uniformity of crop health. Economic analysis revealed that profitability depends heavily on farm size: farms larger than 100 hectares achieved payback periods of 3-5 years, while farms under 50 hectares were not economically viable without subsidies. The findings suggest potential implications for Palestine, where nitrate contamination of groundwater poses public health risks. However, we emphasize that direct extrapolation requires local validation under Palestinian agro-climatic conditions. Cooperative equipment-sharing models could overcome economic barriers posed by small farm sizes. We acknowledge key limitations, including the absence of detailed soil characterization, a two-season dataset, and a lack of grain quality analysis, all of which must be addressed in future Palestinian research.

Nitrogen fertilizer is essential for crop production; however, its inefficient use leads to economic losses and environmental degradation. This study evaluates a simplified NDVI-based algorithm for variable-rate nitrogen fertilization, assessing its agronomic and economic performance with specific attention to potential applicability in Mediterranean and Palestinian smallholder farming systems. Field experiments were conducted over two growing seasons (2020-2022) at three locations in the Krasnodar region of Russia, covering winter wheat and barley across approximately 450 hectares. A simple algorithm was evaluated, calculating variable nitrogen rates for each management zone based on the ratio between zone NDVI and field average NDVI, with clamping limits (0.7-1.3 × uniform rate) for agronomic safety. Results demonstrated that variable-rate application reduced nitrogen use by 14 kg/ha on average (12% reduction) compared to uniform application, with no statistically significant yield penalty (p > 0.05 for all sites). Partial Factor Productivity (PFP) increased significantly from 75.9 kg yield/kg N to 87.0 kg yield/kg N (+14.6%, p = 0.01). NDVI variability across management zones decreased from 22% to 9%, indicating improved spatial uniformity of crop health. Economic analysis revealed that profitability depends heavily on farm size: farms larger than 100 hectares achieved payback periods of 3-5 years, while farms under 50 hectares were not economically viable without subsidies. The findings suggest potential implications for Palestine, where nitrate contamination of groundwater poses public health risks. However, we emphasize that direct extrapolation requires local validation under Palestinian agro-climatic conditions. Cooperative equipment-sharing models could overcome economic barriers posed by small farm sizes. We acknowledge key limitations, including the absence of detailed soil characterization, a two-season dataset, and a lack of grain quality analysis, all of which must be addressed in future Palestinian research.