Influence of Plant Species and Grasslands Quality on Sequestration of Soil Organic Carbon

Soil carbon sequestration plays an important role in mitigating the anthropogenic increases in atmospheric carbon dioxide concentrations. Pastures and meadows are the significant localities for the deposition of soil organic carbon (SOC). The objective was the comparison of the impact of plant species and their quality on the deposition of SOC under the grasslands in 18 variants of meadows and pastures at the original unfertilized soils, the overfertilized soils by organic fertilizers in the form of excrements and the soils after the ecological regeneration by regrassing. The plots 5, 8, 9 and 10 were used on a long-term basis as old semi-natural sheep pastures from the 15 century. We took into consideration the deposits of SOC and N_t in soil. The old semi-natural pasture proved the most intensive transformation and accumulation of SOC (even 5.60%) and the highest values were measured in the depth I (0–100 mm) soil layer, the concentrations decreased along with the depth in all treatments. At these plots, there was the lowest yield of dry matter and quality (E_GQ). The yield of dry matter in t.ha⁻¹, the number of species, E_GQ and C:N in the depth I with the significant impact on the species variability, which were selected by Monte-Carlo permutation test explain up to 47% of the total variability. According to the result of “forward selection” in RDA analysis, out of all significant factors, the number of species has the biggest impact on the total species variability, which represents 17% of the total variability. The total evaluation indicates that from the agricultural aspect of utilization, a more favourable quite high content of SOC was deposited at the ecologically regenerated grasslands by the additional sowing of the valuable autochthonous plant species.