Influence of Fertilizer Practices on Water and the Quality of the Environment.

摘要

Studies on nutrients in deep soil profiles under various management and cropping practices and surveys of nutrients in surface waters,ground water and precipitation indicate that fertilizers are not seriously contributing to the degradation of water and environmental quality in Nebraska. Wheat fallow,alfalfa,and heavily fertilized and irrigated corn on hardlands pose no threat to water or environmental quality. Alfalfa may in fact remove N from deep soil profiles. Nitrogen of geological origin exists in some Nebraska profiles and may contribute to ground water contamination. Phosphorus in Nebraska soil is generally high enough to contribute adequate P for eutrophication when sediment moves from land into streams. Essentially no change occurred in ground water nutrient levels during a 10year period of greatly increased fertilizer use. The results do not indicate a current need for general controls on farmer fertilizer practices but for increased research and development of environmentally sound cropping,fertilizing and irrigation practices.