The purpose of the work is to study the variability of soil density and structure under the break crop influence and the method of basic soil treatment and to identify the most optimal combination thereof to improve the agrophysical properties of typical chernozem. The study was conducted in 2011–2014 in the south-western part of the Central Chernozem Reserve (CCR), Russia. It was found that the density of the 40 cm soil layer before green manure cropping only depends on the main soil treatment method, and before their embedding – both on the soil treatment and on the type of the break crop. The highest soil density was in the black fallow variant – 1.14 g/cm3. The break crop sequence was established, according to which the soil density decreases: annual melilot – mustard – peas – vetch and oats – buckwheat and phacelia. The correlation coefficient r = 0.52 (mean bond) confirms the dependence of soil density during the cover crop embedding on their root weight. A significant decrease in the structural factor during the transition from ploughing (5.2) to energy-saving treatment was found: surface tillage up to 4.6 and subsoil tillage up to 3.9. The improvement of soil structure takes place in the following sequence: annual melilot, vetch and oats, peas, buckwheat, phacelia, mustard. In the south-western part of the CCR, mustard, vetch and oats, buckwheat and phacelia are recommended as a fallow crop with the preferential use of ploughing as the main soil treatment.

No abstract