Influence of No-Till System on the Distribution of Organic Carbon and Nitrogenby Aggregate-Size Fractions in Typical, Ordinary, and Southern Chernozems
The accumulation and distribution of organic carbon and nitrogen in the aggregates of Chernozems (Haplic Chernozems (Loamic, Aric, Pachic), Endocalcic Chernozems (Loamic, Pachic), and Endocalcic Chernozems (Loamic, Aric, Pachic)) during the transition from conventional farming to no-till farming were evaluated. For this purpose, the contents of organic carbon and nitrogen were determined in aggregate-size fractions >10, 10–2, 2–1, 1–0.25, and <0.25 mm. In all no-till Chernozems, the carbon content was higher compared to the Chernozems under conventional system. The dependence of the carbon content on the size of the aggregates was determined for Endocalcic Chernozem (Loamic, Pachic) under no-till system. The total nitrogen content in the soils under no-till system did not differ from the control (conventional system). At the same time, the dependence of the nitrogen content on aggregate size was clearly pronounced in the soils under no-till farming and absent in the soils under conventional farming. In Haplic Chernozems, the higher nitrogen content was found in all agronomically valuable aggregate fractions (10–0.25 mm); in Endocalcic Chernozems (Loamic, Pachic), in fractions 2–0.25 mm; and in Endocalcic Chernozems (Loamic, Aric, Pachic, in fractions <0.25 mm and 2–1 mm. The application of no-till farming system significantly changes transformation patterns of soil organic matter and the biological activity in Chernozems.