Background The traditional cultivation and unique erosion environment in the black soil region of Northeast China has caused serious problems, such as the loss of soil and water and the degredation of soil quality. Facing the threat of soil eorsion, the improvement of the soil erosion resistance is crucial to protect and utilize the black soil resource sustainably. Ecological restoration is one of the effective measures to improve the erosion resistance of soil, and the effect of different vegetations on soil erosion resistance varies according to the plant varieties and configuration methods.
Methods In order to determine suitable perennial grass species and sowing methods for preventing further soil erosion, taking the bare soil without perennial grass as control, the comparative and comprehensive evaluation was conducted on the soil erosion resistance of different native grass species (Elymus dahuricus, Poa pratensis, Bromus inermis), introduced grass species (Festuca elata, Lolium perenne) and different sowing methods (single species: B. inermis, F. elata, L. perenne; mixed sowing: B. inermis – F. elata – L. perenne) after one year of planting and based on five aspects: Soil basic physical and chemical properties, soil aggregate stability, soil anti-erodibility, soil anti-scourability and shear strength.
Results 1) The combination of B. inermis – F. elata – L. perenne significantly reduced soil bulk density and increased soil saturated water capacity; P. pratensis and B. inermis significantly increased the total soil porosity. 2) Planting perennial grass significantly increased soil anti-erodibility and soil anti-scourability and increased the content of water-stable soil aggregates of 0.50– < 1.00 mm in diameter. Among them, the increase of P. pratensis was the largest, which was 1.30 times that of bare soil. 3) The effect of cohesion on soil shear strength was greater than that of internal friction angle, and the cohesion of L. perenne was significantly greater than that of other treatments, 1.72 times that of bare soil.
Conclusions Planting perennial grass can improve soil erosion resistance, the native grass of E. dahuricus is the best, followed by the combination of B. inermis – F. elata – L. perenne. The results can provide references for the selection of grass species and sowing methods for soil and water conservation and vegetation restoration of degraded ecosystems in black soil areas.
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