HUMUS AND LABILE ORGANIC MATTER CONTENT IN CROP ROTATIONS WITH BINARY SEEDINGS
A number of studies have been conducted within stationary multifactorial experiment on typical black soil of detritus content dependence on basic soil treatment modes in crop rotations with binary seedings, fertilizers applied, vegetation period and hydrothermal conditions of the year. Humus losses from top soil in single-crop sunflower sowing have made up 0.6 abs.% from initial values. Binary sowings of sunflower with medick and sweet clover increased its content by 0.2 abs.% compared to initial condition. Disk and subsurface cultivating facilitated debt-neutral humus balance, while plowing lead to its decrease by 2-6% from initial. Detritus content in top soil decreased from seeding to harvesting of sunflower in single-crop sowing, while in binary seedings of this crop there has been a positive detritus increase by 36-74%. The biggest gathering of sunflower seed pods has been gained in binary sowing with medick at all soil treatment modes: plowing - 3.29 t/ha, disking - 3.19 t/ha, subsurface cultivating - 3.24 t/ha, which is by 0.22-0.17 t/ha higher than at check.