Comment pubs.acs.org/est
Agriculture: The Last Unregulated Source
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by highly uncertain market conditions. But corn, in particular, is a “leaky” annual crop. There are long periods when the soil is relatively exposed without a canopy cover. It is prone to leaching and erosion by intense precipitation events, which have been occurring more frequently as a result of climate change. When an intense rainfall occurs before the crop uptakes the applied nitrogen-fertilizer, inevitably, a significant fraction is lost to runoff. Roughly 5% of total annual nitrogen inputs to Iowa soils are measured in streams, a mass representing 20% of the original fertilizer applied on the land (http://www.iowadnr. gov/portals/idnr/uploads/water/standards/nbfull.pdf). So hundreds of millions of dollars in fertilizer value are lost each year to streams and rivers, where the runoff eventually contributes to Gulf Hypoxia via the Mississippi River. Due to favorable weather conditions and advanced seeds in recent years, crop yields have continued to increase. It is a good trend but requires more fertilizers to be applied (hence, more in runoff). Today, the situation has become untenable. EPA strongly encourages Iowa and other agricultural states to adopt water quality criteria for nutrients, but the scientifically determined criteria are more stringent than the quality of most waters in the state. How does one admit that virtually every waterway in the state does not meet designated uses for aquatic life and is “impaired” requiring management action? In reality, Iowa is simply a poster child for a national problem that will require the same type of resolve and investment that we made for point sources through the Clean Water Act. As I see it, we have three options: (1) We can continue business-as-usual which includes voluntary measures that have not been successful in aggregate so far; (2) We can become serious about improving water quality by adopting nutrient quality standards and investing in cost-effective farm programs at the state and national level like we did for point source dischargers in 1972; or (3) We can choose to regulate farm runoff with enforceable permits, while leaving it to farmers to determine how best to meet permitted values (e.g., switching crops, lowering fertilizer application rates, or employing expensive advanced management practices). Personally, I favor the second option, but I wish we could get down to business. Recently, there’s a new wrinkle in the policy landscape for agriculture. Wal-Mart announced last month that it would begin this fall to require supply chain providers of corn, wheat, and soy products to develop fertilizer optimization plans. Suppliers Cargill and Kellogg are already on board. This could require producers to become part of a sweeping sustainability trend that requires certification for high performance. Is supply chain management and certification the answer? Which option do you favor? We’d like to hear from you. Follow us on Twitter @EnvSciTech. Add #agoptions to your comment.
was born and raised in IowaA beautiful state with rolling hills, blue skies, and wide open spaces. And like the people of mythical Lake Wobegone, we want you to believe that everyone here is above average. But I must confessthe water quality here is really terrible. Iowa creeks flow through some of the richest agricultural land in the world, a national treasure. But farm runoff carries an insidious load of soil particles, fertilizers, and pesticides far in excess of what a healthy stream ecosystem demands. The genesis of these rich farm soils was born from endless cycles of prairie grass growth and decay, and from deep penetrating roots which held the soil tightly in place, sequestered nitrogen, added organic carbon, and purified water on a slow path of percolation to streams. Prior to settlement, indigenous people hunted, fished, practiced simple agriculture, and gathered food to support their familiestheir numbers and impact on the environment were much less. But the situation changed dramatically after European settlement. According to accounts by Iowa settlers in the period 1836−1882, the plowing of land and grazing by hogs and cattle in stream margins were particularly damaging, and changes in stream quality occurred in a matter of years: “...The Iowa River used to be a clear stream, except during high water, but now it is always muddy or slimy. The plowing and cultivation of the land causes [sic] more loose soil and vegetable debris to be washed into the river than could be washed in from the native prairie sod; also, nearly every small stream flowing into the river is now utilized as a hog-wallow, or else a hot-day resort for cattle, and the continual filth from these sources passes into the river and contaminates its waters”. (C.R. Mutel, The Emerald Horizon, University of Iowa Press, 2008, p. 130) In the national psyche, agriculture is still sacrosanct. It is not viewed as an “industry” subject to significant regulation. Perhaps because of the universally accepted need for “food security”, agriculture has always been treated favorably when it comes to rules, regulations, and subsidies. We regulate air quality, groundwater, drinking water, toxic substances, and solid waste. So should we not regulate agriculture, one of the biggest industries and the largest source of pollutants to our waterways? Currently, nonpoint sources contribute more than 80−90% of all the N and P discharged to Iowa streams. Prior to the Clean Water Act of 1972, inland waters of the U.S. were polluted mainly by industrial and municipal sewage discharges. But the nation invested more than $100 billion in state-of-the-art municipal wastewater treatment plants over the next 20 years (industry contributed similar expenditures). As a result, lakes and streams became cleaner than at any time in a century. Now, water quality has plateaued or is getting worse due to increasing population and development. The largest source remaining is (by far) nonpoint sources from agricultural runoff. Farmers are not stupid (and Iowa farmers are well above average). They do not apply more chemicals than their crops can uptake. In fact, they are very astute businesspeople driven © 2014 American Chemical Society
Jerald L. Schnoor, Editor-in-Chief Published: April 7, 2014 4635
dx.doi.org/10.1021/es5015168 | Environ. Sci. Technol. 2014, 48, 4635−4636
Environmental Science & Technology
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[email protected]. Notes
Views expressed in this editorial are those of the author and not necessarily the views of the ACS. The authors declare no competing financial interest.
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dx.doi.org/10.1021/es5015168 | Environ. Sci. Technol. 2014, 48, 4635−4636
