The Impact of Land Management Practices on the Composition and Concentration of Biogenic Elements in the Sod-Podzolic Soils of the Middle Ural Region

In a long-term field study conducted in 1977 on stationary plots of fallow and virgin sod-podzolic heavy loam soil in the Middle Urals, the concentrations and reserves of various biogenic elements were determined. The total carbon reserves were found to decrease in the following sequence: temperate forest, fallow land, typical crop rotation, continuous barley cultivation, continuous bare fallow (from 52.8 to 20.7 t/ha). Total nitrogen reserves ranged from 2.4 to 4.5 t/ha. Under the temperate forest, the labile carbon concentration was 0.87%, the hydrolyzable nitrogen concentration was 478 mg/kg, and the mineral nitrogen concentration was 9.2 mg/kg. Due to the presence of meadow vegetation with a large root system, the soil from a 45-year-old fallow had an organic carbon concentration of 1.62% and a total nitrogen concentration of 1568 mg/kg. Phosphorus reserves varied between 1.7 and 4.4 t/ha, depending on the type of land use, while potassium reserves ranged from 30.3 to 74.9 t/ha. Long-term fallowing of the soil resulted in a 29.1% decrease in the accumulation of organic carbon. The concentration of difficult-to-hydrolysis mineral nitrogen compounds decreased by 544 mg/kg and 30 mg, respectively. The organic phosphorus decreased to 205 mg and the exchangeable potassium to 15.5 mg. A crop rotation with two clover fields and fallowing led to an increase in soil fertility, bringing it closer to that of fallow soil. Agrogenic transformations of carbon, nitrogen, phosphorus, and potassium took place, resulting in a reduction in labile organic matter. This was accompanied by an increase in easily hydrolyzable nitrogen from difficult-to-hydrolysable nitrogen and an increase in available phosphate. Additionally, the available potassium increased in the long-term.

long-term stationary experiment, fallow, temperate forest, organic matter