Monitoring of Soil Salinity by Cotton Leaf Parameters and Planting Density

Abstract

The article deals with the problem of organising the monitoring of saline soils using the example of farms in the Hungry Steppe and the Khorezm region of Uzbekistan. Due to the variability of salinity levels, continuous monitoring is required, which is difficult to organise using existing methods. The authors propose the use of a bioindication of soil salinity based on the condition of cotton plants. The aim of the study was to test the possibility of using cotton plants as bioindicators of soil salinity and to search for measurable indicators for the practical implementation of bioindication. As a result of the field studies, possible bioindicators such as leaf thickness, leaf area and the pattern of change in planting density were investigated. It was found that as soil salinity increases, cotton planting density changes according to Poisson's law. In order to minimise the time and work involved in organising the monitoring, it was proposed to use the thickness of the cotton leaf blade, measured with a digital micrometer, as a bioindicator parameter. For the practical implementation of salinity assessment by leaf thickness, the relationship "soil salinity - leaf thickness" was established in the form of a regression equation. The results obtained are similar to those of previous studies on a decrease in plant density, as well as a decrease in the area of the leaf plate and an increase in its thickness with increasing soil salinity. At the same time, the problem of the bioindication of soil salinity by the state of the cotton plant has not been considered so far.