Abstract
Introduction. Sustainable agriculture in the grain-producing regions of Kazakhstan requires a transition from generalized technological solutions to agroecologically differentiated land resource management. In this context, verification of productivity zones identified by NDVI is of particular importance, since remote sensing indices reflect the spatial heterogeneity of crops but do not always explain its soil-landscape and biological causes. Materials and methods. The aim of the study was to perform agroecological verification of NDVI-based productivity zones through the analysis of microrelief, soil agrochemical status, and phenological indicators of agricultural crops. The study was conducted in 2024–2025 on the territory of Olzha-Sadchikovskoye LLP, Kostanay District, Kostanay Region, covering an area of 1,500 ha, including fields No. 18, No. 33, No. 67–71, and No. 90. The study used soil-landscape survey materials, SRTM data, NDVI images, satellite images with a resolution of 2.44–30 m, results of agrochemical analysis of the 0–20 cm soil layer, and field phenological records. Results and discussion. A three-level verification scheme was proposed: the remote sensing level — NDVI; the soil-landscape level — microrelief and agrochemical indicators; and the biological level — plant density and plant height. It was established that stable productivity zones are associated with relief, moisture availability, particle-size composition, and nutrient supply. The stable area of the zones was 72% in field No. 67–71, 43% in field No. 18, and 58% in field No. 90. The content of available potassium increased from slopes to depressions, from 650 to 950 mg/kg. Conclusion. NDVI zones should be considered as a diagnostic layer requiring soil-agroecological and biological verification to substantiate differentiated crop management.