Influence of the Joint Use of Phosphorus and Magnesium Fertilizers on the Background of Nitrogen and Potassium Fertilizers on the Productivity, Quality and Removal of Nutrition Elements in Spring Barley Depending on the Acidity of Sod-Podzolic Soil

In the long term (56 years) field experience revealed a great return from the combined use of lime, phosphorus and magnesium fertilizers compared with the background of nitrogen-potassium fertilizers on strongly acidic sod-podzolic poorly cultivated soil, with a high content of mobile aluminum in it (up to 130 mg/kg), due to the prolonged use of physiologically acidic fertilizers in the form of ammonium nitrate and potassium chloride. The use of phosphorous fertilizers on highly acidic untreated soil contributed to an increase in the yield of spring barley by 67%, on medium-acidic soil produced at a dose of 11.5 t CaCO₃/ha – by 2.3 times, on slightly acidic soil produced at a dose of 19.0 t CaCO₃/ha – by 2.6 times, when combined with magnesium fertilizers – by 2.5 and 2.9 times, respectively, according to compared with the yield on the background of nitrogen-potash fertilizers 1.78 t/ha (highly acidic soil). With the introduction of magnesium fertilizers on slightly acidic soil, the payback by adding grain of mineral fertilizers (N90P60K90) increased by 3 times, increasing to 13.9 kg/kg, with an increase in protein content compared to the background of nitrogen-potassium fertilizers by 1.2%. The use of nitrogen and phosphorus by spring barley plants increased 3.4 times, potassium – 3.0 times.