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United States Department of Agriculture

Agricultural Research Service

Research Project: ENHANCED MIDWESTERN CROPPING SYSTEMS FOR SUSTAINABILITY AND ENVIRONMENTAL QUALITY Title: Nutrient cyling in soils: Sulfur

Authors
item Kovar, John
item Grant, Cynthia -

Submitted to: American Society of Agronomy Monograph Series
Publication Type: Book / Chapter
Publication Acceptance Date: March 2, 2011
Publication Date: April 1, 2011
Citation: Kovar, J.L., Grant, C.A. 2011. Nutrient cyling in soils: Sulfur. In: Hatfield, J.L., Sauer, T.J., editors. Soil Management: Building a Stable Base for Agriculture. Madison, WI: American Society of Agronomy and Soil Science Society of America. p. 103-115.

Interpretive Summary: Sulfur (S) is an essential crop nutrient required for normal plant growth, a fact that has been known since the nineteenth century. Sulfur deficiency will reduce both crop yield and quality. Deficiencies and plant responses to S fertilizer have been reported in crops worldwide, and are becoming more common. The main reasons for recent increases in documented S deficiencies include the reduction of S dioxide emissions from various industrial sources, mainly coal-fired power plants, an increase in the use of fertilizers with little S as an impurity, decreased use of S-containing pesticides, greater S removals with ever-increasing crop yields, and continued losses with erosion of topsoil. The purpose of this chapter is to provide current information on the S requirements of various cropping systems, what we know about S in soil, the best ways of determining crop S needs and managing S fertilizers, and how all of this information can be put together to optimize crop production. This chapter provides a comprehensive overview of S management principles that will assist in the development of improved crop management practices. This information will benefit commercial growers, the fertilizer industry, local environmental groups, and Cooperative Extension personnel interested in alternatives that maximize crop utilization and minimize potential S losses.

Technical Abstract: Sulfur (S) is an essential element required for normal plant growth, a fact that has been recognized since the nineteenth century. It is considered a secondary macronutrient, following the primary macronutrients nitrogen (N), phosphorus (P), and potassium (K), but is needed by plants at levels comparable to P. Sulfur deficiency will impair basic plant metabolic functions, thus reducing both crop yield and quality. Deficiencies and responses to S amendments have been reported in crops worldwide, and are becoming more common. The likelihood of a response is determined by the balance between sulfur supply and crop demand. The main reasons for recent increases in documented S deficiencies include the reduction of S dioxide emissions from various industrial sources, mainly coal-fired power plants, an increase in the use of high-analysis fertilizers with little S, decreased use of S-containing pesticides, greater S removals with ever-increasing crop yields, and continued losses through leaching and erosion of topsoil. The purpose of this chapter is to provide current information on the demand for S in various cropping systems, what we know about the soil supply of S, the best ways of assessing S status and managing S inputs, and how all of this information can be put together to optimize crop production. In each section, references will provide the reader with an opportunity to explore the topic in greater detail than can be given in these few pages.

Last Modified: 11/22/2014