Vegetated earth bund has been widely established to prevent soil erosion of farmland with the slope of 3-5 degrees in Mollisols region of Northeast China. However, a well-adapted vegetation with greater erosion-control and higher economic benefit has not been determined. Here, an artificially simulated rainfall experiment with rainfall intensity of 25 mm h(-1) was conducted on plots with eight kinds of earth bund (six vegetated earth bunds, one naturally grass-covered bund and one artificially bare bund) to investigate the runoff and soil loss process. The economic income of six vegetated earth bunds was also evaluated. The results showed that vegetation growing on earth bund reduced surface runoff and soil loss by 15.3-62.5% and 79.4-93.8%, compared to the bare bund, respectively, of which Medicago sativa, Rheum rhaponticum, Corylus heterophylla and Acanthopanax senticosus showed higher runoff and sediment reduction benefits than natural grass. Surface runoff and soil loss were significantly affected by the diverse community (P < 0.001), especially negatively controlled by plant coverage (P < 0.01). The biomass of legume herb exhibited a higher negative-correlation with surface runoff (P < 0.01) than the whole vegetation (P < 0.05), however, plant diversity and roots had no significant effects on surface runoff and soil loss (P > 0.05). Furthermore, compared to the average farmland economic benefits, Corylus heterophylla, Ribes nigrum, Acanthopanax senticosus and Physalis peniviana improved economic benefits by 1.1-9.9 times, while Rheum rhaponticum and Medicago sativa decreased economic benefits by 22.5% and 32.5%, respectively. Corylus heterophylla and Acanthopanax senticosus with Medicago sativa are highly recommended for controlling soil erosion of earth bund and increasing economic income. Our results provide a scientific reference and technical support for optimizing vegetation measures of slope farmland in Mollisols region of Northeast China.

Vegetated earth bund has been widely established to prevent soil erosion of farmland with the slope of 3-5 degrees in Mollisols region of Northeast China. However, a well-adapted vegetation with greater erosion-control and higher economic benefit has not been determined. Here, an artificially simulated rainfall experiment with rainfall intensity of 25 mm h(-1) was conducted on plots with eight kinds of earth bund (six vegetated earth bunds, one naturally grass-covered bund and one artificially bare bund) to investigate the runoff and soil loss process. The economic income of six vegetated earth bunds was also evaluated. The results showed that vegetation growing on earth bund reduced surface runoff and soil loss by 15.3-62.5% and 79.4-93.8%, compared to the bare bund, respectively, of which Medicago sativa, Rheum rhaponticum, Corylus heterophylla and Acanthopanax senticosus showed higher runoff and sediment reduction benefits than natural grass. Surface runoff and soil loss were significantly affected by the diverse community (P < 0.001), especially negatively controlled by plant coverage (P < 0.01). The biomass of legume herb exhibited a higher negative-correlation with surface runoff (P < 0.01) than the whole vegetation (P < 0.05), however, plant diversity and roots had no significant effects on surface runoff and soil loss (P > 0.05). Furthermore, compared to the average farmland economic benefits, Corylus heterophylla, Ribes nigrum, Acanthopanax senticosus and Physalis peniviana improved economic benefits by 1.1-9.9 times, while Rheum rhaponticum and Medicago sativa decreased economic benefits by 22.5% and 32.5%, respectively. Corylus heterophylla and Acanthopanax senticosus with Medicago sativa are highly recommended for controlling soil erosion of earth bund and increasing economic income. Our results provide a scientific reference and technical support for optimizing vegetation measures of slope farmland in Mollisols region of Northeast China.