Relationship between NDVI index obtained from MODIS and winter wheat yield

Abstract

Programming a high-quality winter wheat crop cultivated using No-till technology is an urgent task for an agricultural producer. The use of No-till technology in soil cultivation in arid climatic conditions of the Pre-Caucasus allows increasing its moisture accumulation. Obtaining a given crop yield is solved not only by ground monitoring and crop control, but also by a system for controlling the production capacity of plants based on remote sensing data of the Earth. Thus, satellite images of various temporal and spatial resolutions provide information on the current state of crops, and field and laboratory studies - on the structural and functional state of the photosynthetic apparatus of plants, which is reflected in crop yields. This combined method makes it possible to have operational information and timely adjust technological operations included in the No-till system for its wider implementation in agricultural production. The research was conducted in 2017-2020 in the arid zone of the Pre-Caucasus on the basis of the agricultural enterprise «Agrokhleboprodukt». Temperature conditions and precipitation were not constant. The average annual precipitation in the territory is 506 mm, the average annual air temperature is 10.1 ° C, and the average annual precipitation is 30.7 mm. During the period under consideration, satellite data confirmed the fact that the values of the vegetation index NDVI grew by an average of 12 % in comparison with the average long-term data. The NDVI index increased from 0.41 to 0.49. At the same time, plant productivity decreased from 4.87 to 3.14 t/ha. The obtained data made it possible to identify a regression relationship between the yield of winter wheat and the vegetation index NDVI (R2 = 0.78) and to predict in 2021 a further decrease in crop productivity (provided that previously identified trends remain) and the need for operational remote and ground control over the state of crops.