108(2)_str 14

ISSN 1392-3196 / e-ISSN 2335-8947
Zemdirbyste-Agriculture, vol. 108, No. 2 (2021), p. 109–116
DOI 10.13080/z-a.2021.108.014

Magnesium leaching processes from sod-podzolic sandy loam reclaimed by increasing doses of finely ground dolomite



The results of 8-variable column experiment on a strongly acidic sod-podzolic sandy loam reclaimed by the finely ground dolomite in a wide dose range are presented. The aim of the research was to measure and estimate leaching of magnesium (Mg) and its migration pattern. The dolomite powder at the different doses calculated by hydrolytic acidity (Hy) was applied at 225, 337.5, 450, 675, 900, 1350 and 1800 mg, that corresponded to 0.5, 0.75, 1.0, 1.5, 2.0, 3.0 and 4.0 Hy, respectively. The migratory ability of Mg was studied in 12-times washing column experiment. Each washing was carried out by 400 ml distilled water, simulating the volume of annual precipitation percolating through the soil stratum yearly. The increase in the amount of leaked moisture contributed to the enhancement of the eluvial losses of Mg. The maximum loss of Mg due to migration was established in the filtrates of the first washing. As the dose of dolomite increased, the amount of the soil Mg migrating with the total amount of Mg decreased from 27% to 7.5%. Complete removal of water-soluble Mg from the soil was not achieved in any of the studied treatments. Applied empirical estimations correctly described the process of leaching of Mg during repeated washing of the soil. Based on the data on the amount of leached Mg from soil reclaimed by a wide range of dolomite doses, a clustering of the empirical equations was performed. It was shown that in the 1st stage of the experiment (from 1 to 4 washings) the rate of Mg leaching increased significantly with an increase in the dose of the dolomite. In the 2nd stage (4 to 12 washings) such a pattern was not established. Depending on the dolomite dose applied, the losses of Mg increased from 14.05 to 50.6 mg compared to 3.8 mg in the non-limed (control) treatment.

The main finding is that finely ground dolomite in an amount exceeding a full dose calculated by 1 Hy applied to sod-podzolic forest soil resulted in unproductive losses of Mg, i.e., with increasing dolomite dose, the losses of Mg increased.

Key words: clustering, empirical estimations, leaching rate, magnesium, migration.

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