ABSTRACT
Abstract Agricultural production systems have been found to have had negative impacts on the overall quality of water resources. Growing environmental awareness in the public has, however, led to improved management systems within agricultural watersheds of the nation to a certain degree. Contamination of surface and groundwater sources by fertilizers and pesticides has been well documented by various state and federal agencies in the United States as a result of agricultural practices in the watersheds. Nation's water resources include underground aquifers as well as lakes, rivers, and the ocean. Agriculture is viewed as a significant nonpoint source of groundwater contamination, presenting a difficult problem for the design of governmental methodologies to prevent pollution. Groundwater contamination is of increasing concern in the United States because about 50 percent of the drinking water comes from groundwater. To society at large and to producers, research and educational programs were initially aimed at water quality protection over compulsory regulations. Several studies were initiated at Iowa State University in the late eighties to evaluate the effects of various agricultural production systems on the environment. The objective of this paper is to review the results of some of these studies that were aimed at reducing the contamination of surface and groundwater sources. Some of the results of these studies indicate that better chemical management practices in conjunction with conservation tillage systems, can reduce contamination potential of nations water resources. Keywords: environmental sustainability, herbicides, nitrate management, subsurface drainage, tillage, water pollution.
