The impact of conservation tillage on pesticide runoff into surface water: A review and analysis

Excerpt

The presence of detectable concentrations of pesticides in surface water has caused some concerns about possible effects on human health and aquatic biology. Herbicides are the class of pesticide most frequently detected. Several popular soil-applied herbicides can be commonly detected in surface water during the growing season and can sometimes exceed drinking water standards (standards based on daily lifetime exposure) following runoff events (1, 31, 37).

Adoption of various Best Management Practices (BMPs) is being urged in many areas to reduce pesticide runoff. Conservation tillage is one BMP commonly suggested for this purpose. As defined by the Conservation Technology Information Center (CTIC) conservation tillage leaves a minimum of 30 percent of the soil surface covered with crop residue after planting (11). Conventional tillage, as defined by CTIC and as used in this article, totally disturbs the soil surface and buries crop residue. The moldboard plow is usually used in these systems.

No-till systems leave the soil undisturbed before planting and complete planting in a narrow (3 to 8 cm or 1 to 3 inches) seedbed. In ridge-till …