ASSESSMENT OF CARBON DIOXIDE EMISSIONS WHEN MINIMIZING THE PRIMARY CULTIVATION OF CHERNOZEM SOIL IN THE NORTHERN FOREST-STEPPE OF WESTERN SIBERIA

Abstract

The problem of climate warming has taken on a planetary character. It has been proven that the annual flow of CO2 from the soils of our planet reaches 50-77 gigatons of carbon dioxide, which increases the temperature of the agroecosystem and creates a greenhouse effect. The scientific community is actively exploring ways to reduce carbon dioxide emissions into the atmosphere and its deposition by the soil. The purpose of the research is to study the effect of minimizing tillage of chernozem soil on the emission of carbon dioxide into the atmosphere. The intensity of carbon dioxide emissions into the atmosphere was studied according to the scheme of application of basic tillage: 1. The fallow (47 years old)- control; 2. The plowing to a depth of 23-25 cm; 3.Combined plowing with a six-year cycle of discing to a depth of 10-12 cm after plowing; 4. Without tillage, with direct sowing of spring wheat (Novosibirskaya 31 variety) SKP-2.1. The repeatability in the experiments was 3-fold, the plots were placed sequentially, the accounting area was 100 m²(25x4). The humus content in the 0-30 cm layer of meadow-chernozem soil is 6.81%, the actual рН is 5.3; with an average content of mobile forms of phosphorus and potassium. The carbon dioxide emission intensity was studied at fixed sites in each variant. Sampling was carried out from steady-state chambers, the base of which, after removing vegetation, was immersed 2-4 cm into the soil. The CO2 content was measured in the laboratory using a LICOR Li-830 instrument. CO2 sampling, measurement of soil temperature and humidity were carried out over 15 times of the growing season with an interval of 7 days. The parameters of the soil temperature of 16.1-18.1 °C, at which the maximum intensity of CO2 emissions into the atmosphere was recorded, and the soil temperature of 8.0-10.8 °C, at which the rate of CO2 emissions decreased to 0.4 kg/ha?hour. An increase in CO2 emissions was also noted in the soil moisture range of 19.1-37.3%, and an increase of over 48% and a decrease of less than 20% leads to one and a half times decrease in CO2 emissions (below 7.5 kg/ha?h). The ecological and economic advantages of combined tillage have been proven, CO2 emissions decreased to 2.7 kg/ha?hour and were 2.2 times lower than in plowing. Minimizing basic tillage allowed us to obtain grain with the lowest cost of 6,806 rubles/ton and the highest profitability of its production.