Possibility of determining the nitrogen content in winter wheat plants during the earing phase using remote sensing data
The study examined the possibility of using remote sensing Data (RED, NIR, NDVI) for monitoring winter wheat crops in production conditions for nitrogen content in plants. This work is divided into two stages: 1) analysis of the correlation between NDVI indicators and nitrogen content on production crops of the North-Caucasian FNAC; 2) comparative analysis of the correlation between nitrogen content and remote sensing data in the conditions of the “Rodina” agricultural enterprise in the Shpakovsky district of the Stavropol territory. Selection of plant samples (sheaf material) was carried out according to the generally accepted method. Repeatability — 4-fold. The chemical composition of plant organs was determined using the method of V.T. Kurkaev and co-authors, and the chlorophyll content was determined by Y.I. Milaeva and N.P. Primak. We used the earth remote sensing data provided by the Terra satellite and obtained by the Modis scanning Spectroradiometer. At the first stage, the relationships between the nitrogen content in winter wheat plants and the values of the normalized difference vegetation index (NDVI) were studied. At the early stages of growth and development of winter wheat plants, high correlation coefficients between these indicators were obtained. Thus, the correlation coefficient on average for the fields in 2012 was equal to -0.89, and in 2013 and 2014 — -0.82. In later phases of growth and development of winter wheat plants, this relationship was not observed. At the second stage, it was found that it is advisable to use the red reflection index to assess the nitrogen content at the local level (a separate agricultural enterprise) in the earing phase. In this case, there is a stable inverse correlation — the average for three years of research was -0.71. When other remote sensing indicators (NDVI and NIR) are used in the analysis, the links are either absent or less apparent.