Abstract
The article evaluates the role of remote sensing in the precision farming system. It has been found that plant and soil diagnostics of nitrogen and phosphorus nutrition play a primary role in the differentiated application of fertilizers. Spectral indices directly dependent on the level of nitrogen nutrition in winter wheat have been identified. Increasing the rate of applied mineral nitrogen from 60 to 180 kg/ha increased NDVI values from 0.64 to 0.72. The residual effect of manure application at 20–60 t/ha altered these values within a narrower range, from 0.62 to 0.67. Potassium fertilizers had little effect on NDVI values, with a slight tendency to decrease as application rates increased. The correlation between nitrogen and chlorophyll content in plants and grain yield was calculated, based on which nitrogen sufficiency indices and "greenness" indices were obtained for different grain yield levels. With the help of portable photometers of NDVI indices obtained with portable photometers is comparable to traditional methods of nitrogen nutrition diagnostics and can be effectively used in precision farming to quantitatively assess the degree of in-field heterogeneity and the nitrogen needs of winter wheat crops.