INFLUENCE OF IRRIGATION WITH II CLASS SUITABILITY OF WATER ON THE SOIL CHEMICAL COMPOSITION

Abstract

Unsatisfactory physical condition of the soil in the village Oleksandrivka (Dniprovskyi district, Dnipropetrovsk region, Ukraine) necessitated a long-term research to find out the cause of this phenomenon. The type of soil of the experimental plot is established – chernozem ordinary low-humus leached on loamy forest. There are the soil section, the results of the spectral analysis of the soil, the humus content and the physicochemical properties of the soil of the research area. The article has the highlights results of chemical analysis of irrigation water from the reservoir on the Samara River. According to the results of the analysis, irrigated water belonged to the II quality class – "Limitedly suitable" in the all years of research. To establish the effect of class II water irrigation, the chemical composition of the water extract was determined. These researches showed on the anionic composition of the increase in SO4 ions relative to the option without irrigation for all years of observation. It was due to the entry of these ions into the soil along with irrigation water. Without irrigation the amount of sulfates gradually decreased. It was 2.25 meq/100 g of soil in the fifth year. There was a clear tendency to increase chlorine ions in irrigation option. The amount of chlorine increased to 1.5 times compared to the non-irrigated option. Therefore, the chemistry of the site was chloride-sulfate and sulfate.
 According to the cationic composition, the largest amount was accounted for by sodium ions. The amount of Na + 1 in the irrigated option increased by 34% on average when comparing with the control option. In the absence of irrigation, the site is slowly desalinated by reducing the ratio of Na/Ca ions by an average of 8.7 units compared to irrigated options. For some years of research the soil without irrigation option was referred to the slightly saline type.