Mulch tillage – principle of preservation of chernozem of the northern steppe of Ukraine

Reclamation and intensive utilization of chernozems of the steppe zone of Ukraine over a long period led to loss of a significant amount of organic matter, agrophysical degradation, and dramatic decrease of soil fertility. Organic products of plant origin – byproducts of field crops (straw, frondiferous residues of arable crops) – play an important role in the renewal of fertility, protection of soils from erosion and accumulation of efficient moisture in the soil. The article presents the results of studying of the agroeconomic efficiency of board, differentiated and shallow (mulching) tillage systems when growing field crops under the conditions of the northern Steppe of Ukraine. There is substantiated the expediency of use of a shallow (mulching) tillage system, which, in terms of crop rotation efficiency against a fertilized background, is highly competitive with board and differentiated systems, as well as has a positive effect on the structural state of the arable layer (the content of agronomically valuable aggregates is 76 %), provides additional (71-85 m3 ha-1) accumulation of efficient moisture in the autumn-winter period. The most of conditional stubble on the surface remains, of course, in the early fallow (without tillage in autumn) – 630 pcs m-2. A significant amount of it was also after disk processing – 333 pcs m-2. Early fallow is a reliable method to wind erosion (deflation) combat in the spring. Even strong winds with a speed of more than 15 m s-1 in early fallow are not able to blow out more than 5-12 g m-2 of soil in 5 minutes of exposure, while in case of board tillage these figures increase by 11-26 times and amount to 134 g m-2.