NDVI of crops as a remote indicator of arable soils quality

The quality of arable soils largely determines the productivity of agricultural crops and the economic efficiency of their cultivation. The purpose of this work is to analyze the relationship between intra-field heterogeneity of crops and vertical heterogeneity of soil skeletality based on a test corn field in Kabardino-Balkaria. The NDVI vegetation index, calculated from Sentinel-2 satellite imagery, was used as an indicator of crop condition. Soil skeletality was determined by dry sieving. It has been established that the value of the NDVI index of crops on a test field can serve as the basis for indirect detection of vertical heterogeneity of agronomically important soil properties. To obtain reliable information, accurate timing of obtaining NDVI values and the crop cultivated in the field is necessary. The indicator reliability of different crops is determined by their phenology and the thickness of the potential root layer. The geography of agronomically important soil properties on the test field does not correlate with the areas of the traditionally compiled soil map. Spatial variation in corn yield on the test field (range 23%) correlates with variation in the soil skeletal profile. To use NDVI values as an indicator of spatial variation in agronomically important soil properties, it is necessary to take into account the type of crop cultivated, careful selection of the date for obtaining NDVI, as well as the availability of a priori expert knowledge about the limiting soil factors in the field, the specific phenology and agrotechnology of crop cultivation.