The article deals with the issues of the state of soil fertility in the serozem zone, its changes during irrigation and long-term use in agricultural production. The essence of agrotechnology developed to improve soil properties by using agrotechnology aimed at enriching soil with organic matter in relation to various soil and climatic zones of the republic is given. This requires the mandatory use of organic, organomineral fertilizers, composts, green manure (sowing of intermediate crops), the development of crop rotations, crop alteration, which contribute to obtaining a high yield and biomass. Below we dwell on individual results when using this agricultural technology for organic farming in the conditions of cultivation of crops of the cotton complex. In our studies, using this agricultural technology, in the conditions of irrigated typical serozem soils, cotton was grown in the first year, then winter wheat, the next year, re-crop (mung bean), and intermediate autumn crop (rye). So, on cotton crops, without the application of mineral fertilizers, the use of 10 t/ha of biohumus, BMG-organic part of the production of biogas technology, as well as 30 and 40 t/ha of organic fertilizer - manure, in comparison with the initial content, for the vegetation season of cotton allowed increase the content of humus (organic matter) in the 0-50 cm soil layer by 0.077-0.098% or 3.08-3.92 t/ha. And in the control variant with the use of only mineral fertilizers, a decrease in humus in the 0-50 cm soil layer by 0.106% or 4.24 t/ha was noted. In the experiment with autumn wheat, similar positive results were obtained in relation to the humus content on variants with organic fertilizers. Depending on the type of fertilizer in 0-50 cm soil layer, in comparison with the initial content, an increase in humus by 0.437% was noted; 0.201%; 0.214% and 0.310%, which is equal to 17.48; 8.04; 8.56 and 12.40 t/ha. The yield of wheat in the control variant was 51.6 centners/ha, and in the variants with organic fertilizers, an increase from 3.8 to 10.6 centners/ha was obtained. In accordance with agricultural technology, after the cultivation of autumn wheat, a second mung bean crop was sown. According to the data obtained, with a mung bean yield in the control variant of about 15.0 centner/ha, in the options with organic fertilizers, the increase from 10 t/ha of biohumus and BMG was 4.0 and 3.8 centner/ha, and from 30 t/ha and 40 t/ha of manure - 1.5 t/ha and 2.0 t/ha, respectively. After re-culture, mung beans were grown as an intermediate crop - rye for green manure. This completes the crop rotation. In the spring of the next year, second-year cotton was grown again. At the end of the second time, it was grown in a 0-50 cm soil layer on the control variant, an increase in the humus content by 0.235% or 9.40 t/ha was noted, and on the variants with organic fertilizers, respectively: 0.527; 0.718; 0.376 and 0.477%, which is equal to 21.1 in t/ha; 30.7; 18.0 and 19.1. In the experiment of the first year of cotton cultivation, the average yield in the control variant was 32.4 centner/ha. On the variants of the experiment with only organic BMG and biohumus at a rate of 10 t/ha, the increase was 1.0 and 1.7 centner/ha, respectively, on the options with manure at a rate of 30 and 40 t/ha, the yield was less by 1.4 and 1.1 centner/ha. In the experiment of the second time of cotton cultivation, the yield on the control variant with mineral fertilizers was 36.7 centner/ha. In the variants of The experiment with only organic fertilizers, the increase was: from manure in the amount of 0.6 c/ha and 2.7 centner/ha, and from biohumus - 2.3 centner/ha and BMG - 1.2 centner/ha.
Tashkuziev et al. (Tue,) studied this question.