What is a way to decrease the amount of water pollution?

Use contour plowing, and plant lines of trees and tall grasses to provide vegetative buffers to reduce runoff and soil erosion.

Some organic farms use no-till methods (not plowing) this greatly reduces the amount of soil lost to erosion.

Pesticides and nitrates from fertilizers, and animal are a major cause of water pollution. It is estimated that farmers spray 10lbs of chemicals on each acre, and 20% of the chemicals runoff into local rivers and streams. The reduction of chemical pesticides and fertilizers help.

Also, the creation of a wetland or marsh around the area helps to take up the nitrates from fertilizers and animal wastes.