Properties of Solonetz and Solonetzic Soil during Their Cultivation in Crop Rotations with Potato Specialization under Conditions of the Trans-Volga Region
The area of saline soils in the Russian Federation is 38 million hectares. The high content of sodium in soil adsorption complex determines the number of negative properties. From agrochemical characteristics it is high alkalinity, the formation of chlorides and sulfates of sodium, consequently, the microbial activity is depressed, and the soil could become low suitable for plants. The high content of sodium in the soil adsorption complex stipulates for the extremely bad physical properties, which is especially unfavorable for potato. Because of the high hydrophilicity of colloids, in the case of precipitation, the soil swells, this worsens the quality of planting, delays its timing. And in the autumn it makes impossible the mechanical harvest; losses sharply increase. The dry autumn is even worse: the fritted soil complicates the work of combines, there is a lot of ground in the bunker, the tubers are severely injured and poorly stored. The ways of radical improvement of the main agronomic properties of such soils can be outlined in accordance with the results of the multicriteria analysis carried out. The type of salinity is determined for 11 crop rotation fields of OOO “Agro-Solana”, the solonetz process is determined and the dose of gypsum-containing substances is calculated on this basis. In the sulfate-chloride type of salinity, the content of exchangeable sodium in solonetz reached 21.5-27.2%, in solonetzic soil - 11.5-17.1%, in weakly solonetz soil - 6.1-9.7%. Accordingly, the doses of gypsum in terms of the mass fraction of the main substance (CaSO4xH2O) on solonetz were 8.6-18.0 t/ha, on solonetzic soil - 2.5-10.5 t/ha. On weakly solonetzic soils, gypsum application was not advisable. Conceptual approaches to the implementation of the cultivation program are determined, in particular, the composition of specialized crop rotations with various crops, improving solonetz soils, is recommended.