<CENTER> <FONT SIZE="+2" FACE="Arial"><B>Economic Effects of Controls on Nitrogen Fertilizer</B></FONT><P> </CENTER> <TABLE BORDER="0" WIDTH="100%" CELLPADDING="10"> <TR> <TD WIDTH="65%" VALIGN="TOP"> In recent years the role of agricultural chemicals as water contaminants has become a matter of increasing concern among people who are interested in the quality of the environment. Before controls are undertaken, however, the problem of reducing contamination should be examined from various perspectives. This bulletin looks at the economic effects that six alternative methods might have in the agro-environmental complex if attempts are made to control the use of commercial nitrogen fertilizer. Although much of the work concerns Illinois, many of the results of these analyses can be applied elsewhere as well.<P> During the 1950's and 1960's the nitrate content of ground and surface water increased substantially, especially in the Midwest. This increase was apparently related to the expanded use of commercial fertilizers and more intensive farming. Increased quantities of both phosphorus and nitrogen in nonflowing water can stimulate algal growth, which eventually adds to the decaying organic matter and may reduce oxygen to critical levels for aquatic life.<P> Human and animal health can also be endangered by excess concentrations of nitrates, which are a form of nitrogen. Under certain conditions bacteria in the intestinal tract of both humans and animals reduce nitrates to nitrites. When absorbed into the bloodstream, nitrites change hemoglobin into methemoglobin, which cannot carry oxygen to body tissue. Oxygen levels are lowered, and when more than 70 percent of the hemoglobin is changed into methemoglobin, death may result. Infants under six months of age, especially those with digestive disorders, are particularly vulnerable. In addition, according to Lijinski (1971), some of the nitrosamines formed by the reaction between nitrites and certain organic compounds produce cancer in laboratory animals.<P> Researchers are still uncertain about the possible link between human health hazards and the use of commercial nitrogen fertilizers and other sources that raise the nitrate content of water. In some areas of the United States the nitrate concentration in water, expressed as nitrate-nitrogen, chronically exceeds the standard of SOT parts per million, in some cases up to ten times this level, yet no serious health problems have been linked to nitrates in these areas. Even so, the possibility that hazards may develop warrants an investigation of the economic effects of various control measures. <P> Commercial nitrogen fertilizers are only one source of nitrates. Nitrates are also derived from mineralizing soil organic matter, precipitation, fixation of atmospheric nitrogen by soil organisms, animal and human metabolic wastes, and organic wastes from industries that process food, paper, and pulp. It should be emphasized that the nitrate ions from these other sources are as subject to leaching as the ions from commercial nitrogen fertilizer. The amount of nitrate moving into water would probably be the same if the same amount of nitrogen were supplied from sources other than nitrogen fertilizer. However, because nitrogen fertilizer adds a significant quantity of nitrates to water, it is prudent to examine the consequences of policy alternatives that might control this source but still meet food production needs (Aldrich, 1972). <P> </TD> <TD WIDTH="45%" VALIGN="TOP"> <CENTER> <FONT FACE="Arial"><B>Contents</B></FONT><P> </CENTER> <UL> <LI><A HREF="index1">Nitrate Controls and Water Quality</A><BR> <LI><A HREF="index2">Education as a Means of Voluntary Restriction of Nitrogen Fertilizer</A><BR> <LI><A HREF="index3">Per-Acre Restrictions on the Use of Nitrogen Fertilizer</A><BR> <LI><A HREF="index4">An Excise Tax on Nitrogen Fertilizer</A><BR> <LI><A HREF="index5">A Market for Rights to Use Nitrogen Fertilizer</A><BR> <LI><A HREF="index6">Restrictions on Nitrate Concentration in Groundwater</A><BR> <LI><A HREF="index7">Below the Root Zone </A><BR> <LI><A HREF="index9">A Total-Farm Nitrogen Balance</A><BR> <LI><A HREF="index10">Summary</A><BR> <LI><A HREF="index11">Bibliography</A><BR> </UL></TD></TR></TABLE><BR> [<A HREF="./noframe/page2.html">next</A>]