Intensification techniques in agriculture influence on the leached chernozem algoflora

The purpose of research is to study the reaction of the algal flora of leached chernozem to agricultural technology with different levels of use of chemicals in a six-field grain-grass crop rotation. Tasks: to identify the effect and aftereffect of mineral and organic fertilizers on the number of soil algae; determine the most sensitive group to the agrochemical load of the soil. The object of research is the algoflora of leached chernozem: from eukaryotes - green (Chlorophyta), yellow-green (Xanthophyta), diatoms (Diatomeae); from prokaryotes - cyanobacteria (Cyanobacteria) or blue-green algae. The analysis of the effect of the studied factors was carried out according to the quantitative indicator used in algology: the number of cells in one gram of soil (cells/g of soil). Accounting was carried out on an MBI-6 microscope by direct counting. The stationary experiment was established in 1986 in the southern forest-steppe zone of Western Siberia (the Omsk Region). The studies were carried out under alfalfa plants of the first and third years of vegetation. In the split-plot experiment, three factors were studied: chemicals (fertilizers and plant protection products), cattle manure and straw. When applying the maximum dose of mineral fertilizers (N40P120K40) in combination with plant protection products, the total number of living algae cells decreased by 70 % compared to the unfertilized background (102.4 thousand cells/g of soil). The introduction of manure (10 t/ha of crop rotation area), straw (in an amount corresponding to the harvest) on the same mineral background leveled the depressive effect of chemicals. The number of cells increased by 98 % compared to the variant without the use of organic fertilizers. The negative impact of agrochemical agents on the algal flora manifested itself directly in the year of introduction; in subsequent years, the number of algae cells increased significantly. Under alfalfa of the third year of vegetation, green and yellow-green cells accounted for 66-97 % of the total number of living cells. The obtained data can be used for purposeful control of the ecological situation in the agrocenosis.