Ecological assessment of the impact of agricultural activity on the emission of carbon dioxide from the leached chernozem of the Tobol-Ishim interfluve
The purpose of this work is to study carbon dioxide emissions from the surface of virgin and arable chernozem during the growing season of the Tobol-Ishim interfluve. Methods. The study was conducted on virgin land, in pure steam, under grain crops and corn from May to October. The intensity of carbon dioxide release was determined by the method of Shtatnov with titration in the field. Results. Based on previous studies, based on scientifically based approaches, as well as our own experimental data, the relationship between carbon dioxide emission and hydrothermal conditions of the humus layer (0-30 cm) was investigated, and the degree of influence of the type of land and crops on the release of CO 2 from the surface of leached chernozem was determined. It has been established that the chernozems of Western Siberia are characterized by very low biological activity in the spring and autumn periods. CO 2 emissions in May averaged 1.0-1.6 kg/ha per hour with a coefficient of variation of 8 %. The peak release of carbon dioxide into the atmosphere occurs in June-July (2.6-6.5 kg/ha per hour). It was revealed that under grain crops the gaseous losses of C-CO 2 in the summer period amount to 4.1-6.5 kg/ha per hour, and in the area of pure steam - 2.3-3.4 kg/ha. The determining role in the intensity of carbon dioxide release is played by the soil temperature ( r = 0.7). During the years of research, there were no dry periods, which did not allow us to establish a reliable effect of soil moisture on CO 2 emissions, the correlation coefficient was 0.2 units. Based on the results obtained, a low degree (12.8 %) of the influence of the type of land (virgin land/arable land) and crops (cereals/corn) on the intensity of carbon dioxide release into the atmosphere from the surface of chernozem was revealed. The maximum degree of influence was in hydrothermal soil conditions (65 %), on which the activity of the soil microbiota and the root system of plants depended. Scientific novelty. For the first time, the intensity of carbon dioxide release from the surface of leached chernozem was studied for the Tobol-Ishim interfluve and the degree of influence of the anthropogenic factor against the background of the hydrothermal regime of soil was established.