The planting of fruit trees on sloping land can bring significant benefits to the local economy, but it also causes different degrees of soil and water erosion problems. In this study, we investigated the differences in nutrient migration in slope ditch runoff. In 39 scouring tests, a grass ditch reduced the loss of carbon (C), nitrogen (N), and phosphorus (P) by intercepting runoff. There was a positive correlation between runoff and the loss rate of N and P. The flow affected the retention time of runoff in the ditch, and then changed the dissolved organic carbon (DOC) loss rate in the runoff. The concentration of N and P did not affect the N and P loss rate, but did affect the total amount of N and P lost and the DOC loss rate in the runoff. The addition of organic fertilizer significantly increased the N loss rate in the runoff, and the change rule of the P and DOC loss rate was similar; thus, co-migration might have occurred. To sum up, the importance of the four factors on the migration and loss of C, N, and P in ditch runoff was as follows: organic fertilizer (100%) > fertilizer concentration (74.8%) > ditch type (12.6%) > initial flow (10%).

The planting of fruit trees on sloping land can bring significant benefits to the local economy, but it also causes different degrees of soil and water erosion problem. In this study, we studied the difference of nutrient migration in the slope ditch runoff. In the 39 scouring tests, grass ditch could reduce the loss of carbon(C), nitrogen(N) and phosphorus(P) by intercepting runoff. There was a positive correlation between runoff and the loss rate of N and P. Flow affected the retention time of runoff in the ditch, and then changed dissolved organic carbon (DOC) loss rate in runoff. The concentration of N and P wouldn't affect N and P loss rate, but would affect N and P total loss amount and DOC loss rate in runoff. The addition of organic fertilizer would significantly increase the N loss rate in runoff, and the change rule of P and DOC loss rate was similar, the co-migration may occurs. To sum up, the importance of the four factors on the migration and loss of C, N and P in ditch runoff was as follows: organic fertilizer (100%) > fertilizer concentration (74.8%) > ditch type (12.6%) > initial flow (10%).