A water regime of leached chernozem in long-term application of different systems of main soil treatment in crop rotation with oil crops

A water regime of leached chernozem was studied depending on systems of primary soil treatment (intensive, plowing in different depths, minimal and surface) in crop rotation with oil crops (sunflower, castor, soybean, winter and spring rapeseed) in VNIIMK stationary trial in four rotations of ten-field rotation with cereal and tilled crops in 1971-2012. A forty-year application of different systems of primary soil treatment in environments with unstable moistening in rotation with oil crops did not influence significantly on changes of the water regime. But there were noted an increase of annual amount of precipitations and a redistributions of its most part on autumn and winter seasons, along with a tendency of an increase of average daily air temperature. Thus, the role of soil treatment with a positive impact both on input and output of water in soil is rising. The first rotation showed that methods of minimal treatment, less differed with depth, effected significantly on water permeability of soil. A plough treatment on 12-14 cm decreased moisture absorption by soil up to 23 %, and a disk treatment on 8-10 cm reduced it up to 44 % in comparison with deep plowing; therefore deposits of moisture in spring were a little bit lower at surface treatments than at plowing. The regular moldboard and subsurface plowings in rotation with oil crops provide more productive accumulation of precipitations in autumn and winter in agrophytocenoses and can be considered as a key method of zonal agricultural practices on leached chernozem of the Western Ciscausasia.