Fixation of Potassium and Magnesium by the Soil of Agrocenoses

It was found that the soil of the agrocenosis with a long-term deficit balance of potassium and magnesium recorded 60-70% of potassium introduced with fertilizer and 20-30% of magnesium. With a positive balance of these elements in the agrocenosis, the fixation of potassium by the soil decreased to 40, and magnesium - to 6-10%. The introduction of increasing doses of potassium fertilizer did not affect the soil level of the content of exchangeable magnesium, the use of magnesium fertilizers did not change the content of exchangeable potassium in the soil. The combined use of moderate doses of potassium and magnesium fertilizers contributed to a decrease in potassium fixation by 10-16% compared with its separate application, while the intensity of magnesium fixation did not change. With increased doses of potassium, its fixation by the soil did not depend on the additional addition of magnesium, and magnesium fixation significantly decreased.