Manure management with conservation tillage

The connection between soil and water resources is so intimate that any change in one usually affects the other. It was assumed for many years that soil conservation practices not only protected the soil but enhanced water quality as well. This assumption was first seriously questioned in the early 1970s as environmentalists began to look for “best management practices” (BMPs) for control of agricultural nonpoint source pollution (NPS). The general notion that soil and water conservation practices (SWCPs) were good for water quality was neither specific nor substantiated enough for blanket acceptance of SWCPs as BMPs, thus a number of questions have been raised. Which soil conservation practices are candidate BMPs for which water pollutants? How specifically do the various SWCPs affect the fate, and particularly the transport of different potential water contaminants? Might not some SWCPs result in even greater use of chemicals that are potential water quality contaminants? In general, we found that when a practice is applied with a specific objective in mind, (e.g., conservation tillage for soil erosion control or reduced fertilizer use to prevent groundwater pollution) changes occur which affect the total system -including physical, economic and even social components - in complex ways. As an old axiom states, “There are many simple answers to complex questions, but most of them are wrong.”.