Effect of Different Levels of Moisture Availability on Magnesium Losses from Sod-Podzolic Soil Calcified with Dolomite. Empirical Models of the Eluviation Process

In a 14-year 10-variant laboratory experiment on columns, the migration mobility of magnesium, which remains annually in dolomite-reclaimed sod-podzolic soil after harvesting, was studied. A “pool” of magnesium compounds capable of migration has been identified during the years of “average long-term”, “excessive” and “insufficient” moisture levels. It was found that an increase in the volume of drained moisture contributed to an increase in unproductive magnesium losses. The higher the dose of dolomite and the smaller the particle size, the greater the eluvial loss of magnesium. The bulk of the migration-capable magnesium was removed from the soil at the initial stage of washing. During the entire study period, migration losses of magnesium after pea harvesting exceeded losses after mustard cultivation. A ranking of various experimental options was carried out according to the scale of magnesium losses. It is shown that over 14 years of observations, the maximum loss of magnesium as a result of migration was typical for the variant produced by dolomite flour, calculated from the full dose of hydrolytic acidity (Ah). Magnesium losses from soil reclaimed by dolomite particles 5–7 and 7–10 mm in size in doses equal to 1, 3 and 5 Ah were lower. Empirical dependences have been developed describing the loss of magnesium from the soil produced by dolomite in a wide range of doses. The graphs of the models for each of the variants with different levels of moisture availability were almost parallel, they were located on top of each other depending on the degree of moisture. This indicated that the mechanisms of magnesium migration, regardless of the degree of soil moisture, were of a similar nature. The degree of moisture affected only the total migration volumes of the element.