The overall impacts of organic agriculture are beneficial to the environment. Certified organic production methods prohibit the use of synthetic fertilizers and pesticides, thus reducing chemical runoff and the pollution of soils and watersheds. Smaller-scale organic farming often is associated with significant environmental benefits, owing to the use of on-farm inputs, such as fertilizers derived from compost created on-site. By comparison, large-scale organic farms often require inputs generated off-site and may not employ integrated farming methods.