DYNAMICS OF MOBILE PHOSPHORUS IN ARABLE CHERNOZEM UNDER LONG-TERM USE OF ORGANIC-MINERAL FERTILIZING SYSTEM IN THE FOREST-STEPPE ZONE OF THE TRANSURALS
The effect of mineral fertilizers applied for the planned productivity of spring wheat and oat to 6.0 t/ha on the background of straw plowing in a grain-fallow crop rotation on the content and stocks of mobile phosphorus in arable leached chernozem has been studied in a long-term field experiment. It has been established that phosphorus consumption occurs in the 0- to 40-cm layer, while its compensation by fertilizers occurs only in the 0- to 20-cm layer. The straw plowing partially returns phosphorus in the soil, but it does not solve the problem of stabilization of the phosphoric status in an arable land. The obtained results can be used at the optimization of fertilizing system for grain crops.