The objective of the research is to reveal the best predecessor for winter wheat cultivated at erosion-prone slopes. The study was carried out in multi-factor experiment at the slope of the gully Bolshoy Log in Aksay district of the Rostov region in 1988–2014. The experiment has been laid in 1986 in a system of contour-landscape organization of the slope territory. In the experiment winter wheat was sown after such predecessors as bare fallow and winter wheat. The experiment was deployed in space and time in triple replication. Plots were allocated randomly. Water regime of winter wheat was studied which was determined by hydrothermal conditions of the agricultural year, primarily by quantity and allocation of atmosphere precipitations through the periods. The number of years favorable for the crop growing (hydrothermic coefficient 1.1–1.6) is 19 %, other years can be attributed to the adverse ones. During favorable years the plots under bare fallow accumulate in cold period up to 34.6 % from the total amount of precipitations fell during the same period, in adverse years – up to 52.6 %. It was revealed that total water consumption in dry years was greater than in very dry years by 18.1 % under bare fallow predecessor, in weakly dry and wet years under the same predecessor was greater by 42.0 %. After winter wheat as predecessor total water consumption was greater by 30.0 and 56.7 % respectively. While winter wheat growing the coefficient of water consumption in weakly dry and wet years comparing to very dry years was by 11.7 % lower after bare fallow and after winter wheat – by 59.1 %.
Keywords: winter wheat, heat-moisture content, hydrothermic coefficient, accumulation of precipitation, productive moisture, total water consumption.
