Dynamics of mobile potassium in typical black soil in short-term crop rotations

Abstract

Changes in the content of the exchange potassium of the soil in the system of short-rotation crop rotations depending on the saturation and placement of crops in them was shown their intensification (fertilizer system).
 Quantitative changes in exchangeable potassium in soil during vegetation of plants hanges depend not only on their consumption by plants, but also on the intake of potassium from organic compounds into the soil solution. In particular, direct application of 20-40 t / ha manure together with N60-100P40-100K60-100 for row crops, provides a high content of exchangeable potassium: after the cultivation of corn - 110-140 mg / kg, sugar beet - 140-200, sunflower - 130-220 mg / kg. The lowest content (70-80 mg / kg) of exchangeable potassium was observed in all fields of control crop rotation (without fertilization), where potassium of the soil and root residues of the cultivated crops served as a source of potassium for plants. Also in most fields after harvesting barley spring (100-120 mg / kg), for applying under the culture of N60P40K60.