Effects of Different Inflow Rate Patterns and Distributions of Grass Strips on Runoff and Sediment in an Engineering Accumulation Body

Engineering accumulation bodies are critical sources of artificial soil and water loss. The objectives of this study were to evaluate the effects of different inflow rate patterns and distributions of grass strips on runoff and sediment in engineering accumulation bodies. A field runoff plot (20 m long, 1 m wide, and 0.5 m deep) was used for inflow simulation experiments under four inflow rate patterns (even, rising, falling, and rising-falling) and five grass strip patterns (patterns Ⅰ-Ⅴ). The results showed that the changing trends of runoff rate and sediment yield increased with increasing inflow rate and decreased with reduction for the same grass strip pattern. Although the inflow rate pattern affected runoff and sediment yield, it had no significant effect on the total runoff and sediment. The influence of the grass strip pattern on runoff and sediment was significantly higher than that of the inflow rate pattern. The runoff reduction and sediment reduction effects of grass strip patterns were 12.23 to 49.62% and 12.92 to 80.54%, respectively. When grass strips were distributed on a slope in bands (pattern Ⅴ), the soil and water conservation effects were ideal, reducing the average runoff and sediment by 44.98% and 58.09%, respectively. Sediment reduction caused by decreasing runoff (SRR) was the main factor controlling erosion and sediment yield. This study can guide the configuration of vegetation control measures for soil and water loss in engineering accumulation bodies.

Effect of Biochar on Soil and Water Loss on Sloping Farmland in the Black Soil Region of Northeast China during the Spring Thawing Period

Biochar, as a kind of soil amendment, has attracted wide attention from scholars in various countries, and the effects of biochar on soil and water loss have been well reported. However, soil erosion is significantly affected by geographical conditions, climate, and other factors, and research on the characteristics of soil erosion and the effects of biochar application in seasonally frozen soil areas is currently unclear. The purpose of this study was to explore the effect of corn straw biochar application on soil and water conservation during the spring thawing period. Specifically, through field experiments, the addition of 0, 6, and 12 kg m−2 biochar on slopes of 1.8, 3.6, 5.4, and 7.2° and the effects on runoff and the soil erosion rate of farmland were analyzed. The results showed that in the 6 and 12 kg m−2 biochar addition treatments, the saturated water content of the soil increased by 24.17 and 42.91%, and the field capacity increased by 32.44 and 51.30%, respectively. Compared with the untreated slope, with an increase in biochar application rate, runoff decreased slightly, and soil erosion decreased significantly. This study reveals that biochar can be used as a potential measure to prevent soil and water loss on sloping farmland in cold regions.