Ag media is like the sound of thunder at 3 a.m. when I’m suffering from an inspiration drought. I can always count on them, especially the communication shops at the advocacy organizations, to provide a timely soaker just when I’m most parched.
The most recent gully-washer was a You Tube video posted by our favorite insurance company. Four middle-aged and snappily-dressed Randys, looking as though they saw no need to change clothes after just filming a Cialis commercial, pose as Iowa farmers chugging coffee in a small town café. Also making an easy transition from the Cialis set is the bragging about their performance, but in this skit the boasting relates to their success in reducing nutrient pollution. Astonished waitresses look on admiringly as these virile countryside titans extol the enormity of their prowess in satisfying Iowans’ urges for cleaner water. The background narrator tells us that “Iowa farmers are celebrating the decline of nutrients in surface water” and, “their ongoing voluntary efforts like no-till, terracing and contour farming have made Iowa’s waterways cleaner,” and finishing with “Iowa farmers, doing their part to make a difference.”
It’s hard to know where exactly to begin farming this virgin soil, but let’s start with the no-till. Only about 1/3 of our cropped acres are classified as no-till (1), and that doesn’t mean those acres never get tilled. A farmer might till a field for a corn crop but not the following soybean crop. Only about ¼ of our no-till area is planted to corn (2).
Secondly, yes, we have a lot of terraces. I once heard a guy from the Agribusiness Association of Iowa boast that Iowa farmers have erected a length of terraces that exceeds the combined length of all our streams. I have no reason to doubt this claim, but it only takes one glance or sniff of our lakes and streams to know that terrace length doesn’t mean everything. A mile of terrace does not give you a mile of good water. Taxpayer-funded terraces do a fine job of increasing the value of a farmer’s land investment by enabling sloped land to be cropped in the first place. So yes, if you insist on cropping a steep hillside, you’re going to need a terrace to reduce soil erosion. But downstream consequences are not always or even usually beneficial. Surface runoff water is captured by intake structures and routed directly to streams. This water is what we call “sediment hungry”, meaning it is energized and capable of aggressively eroding stream banks and beds, increasing stream sediment transport in some circumstances. And terraces can increase stream nitrate through a couple of mechanisms—firstly, they bring uncropped and unfertilized land into production, and secondly, they increase infiltration in and around the terrace, providing a nitrate loss pathway to the stream (3,4).
Lastly contour farming. Are we really still giving farmers the ‘attaboy’ for contour farming? Congratulating farmers for contour farming is a bit like applauding Nurse Ratched for trying to improve her beside manner. If you don’t know, contour farming is when farm rows follow a constant elevation line around a hill, as opposed to cropping up and down the hill with rows of varying elevation, which is much more erosive. If you live in Iowa you know that a lot of it is hilly; without contour farming, we’d be comparing our crop outputs with Kentucky and not Illinois because most of our farms would be in the Gulf of Mexico. Contour farming has been used as an environmental virtue signal for decades and even as far back as 75 years ago, Aldo Leopold (5) called out the phonyism of this bragging: “If he (a farmer) plants his crops on contour, he is still entitled to all the privileges and emoluments of his Soil Conservation District.” So please, just spare me on contouring.
To finish up with the assertion that nutrients have declined in surface water, well, I’m tempted to embed that Jennifer Lawrence mocking thumbs up gif. In fact, that gif could serve as the entire blog post, and I could’ve saved you five minutes. Not an iota of actual water monitoring data could have went into that mendacious claim. Yes, some models do show phosphorus reductions based on practice adoption (like no-till and terraces), but this is not borne out by the water quality data for Iowa streams (6). And literally no one is convinced that nitrogen levels are declining; in fact, there are strong upward trends statewide since 2003 (7).
So in conclusion, if you find yourself believing cropaganda for more than four hours, please call your doctor immediately.
- USDA Census of Agriculture. https://www.nass.usda.gov/Publications/AgCensus/2017/Full_Report/Volume_1,_Chapter_1_State_Level/Iowa/st19_1_0047_0047.pdf.
- USDA Economic Research Service. https://data.ers.usda.gov/reports.aspx?ID=17883.
- Schilling, K.E., Tomer, M.D., Gassman, P.W., Kling, C.L., Isenhart, T.M., Moorman, T.B., Simpkins, W.W. and Wolter, C.F., 2007. A tale of three watersheds: Nonpoint source pollution and conservation practices across Iowa. Choices, 22(2), pp.87-95.
- Gassman, P.W., Tisl, J.A., Palas, E.A., Fields, C.L., Isenhart, T.M., Schilling, K.E., Wolter, C.F., Seigley, L.S. and Helmers, M.J., 2010. Conservation practice establishment in two northeast Iowa watersheds: Strategies, water quality implications, and lessons learned. Journal of Soil and Water Conservation, 65(6), pp.381-392.
- Leopold, A., 2014. The land ethic. In The ecological design and planning reader (pp. 108-121). Island Press, Washington, DC.
- Schilling, K.E., Streeter, M.T., Seeman, A., Jones, C.S. and Wolter, C.F., 2020. Total phosphorus export from Iowa agricultural watersheds: Quantifying the scope and scale of a regional condition. Journal of Hydrology, 581, p.124397.
- Jones, C.S., Nielsen, J.K., Schilling, K.E. and Weber, L.J., 2018. Iowa stream nitrate and the Gulf of Mexico. PloS one, 13(4), p.e0195930.