PHOSPHATE REGIME OF BLACK SOILS LEACHED IN PREOBYE UNDER DIFFERENT TECHNIQUES OF FERTILIZERS APPLICATION
It is established that black soils leached in Preobye’s northern forest-steppe have low content of easy available phosphorus (I). The fertilizers, applied to with all the techniques known, did not return wheat-consumed phosphorus form and its plough layer content decreased in the range: row – local – spread. The content of mobile phosphorus (O) in black soils leached is high, its relation to the easy available phosphorus is poor (I) and does not show actual requirements of plants for phosphorus. Yearly application of fertilizers when seeding at the dose of N35Р42К30 in rows steadily maintained the amount of mineral phosphates in the plough layer and increased it in the subplough layer at the expense of phosphates of active fractions. This provided the productivity of spring wheat reaching 25–28 hwt/ha with minimal tangible costs to achieve this productivity.