What makes it more impressive comes when you think of what that map represents, some 36 million acres of land, and to think of how those acres are used, and what we are doing to protect them.
Even though it’s mainly a road map, we see those roads plotted on a landscape that we know is mostly farmland — rivers, lakes and streams running through it, and dominated by it.
Each five years the United States Department of Agriculture puts out a census of agriculture. The last one from 2012 shows just how agriculture dominates our land. About 24 of the 36 million acres are in cropland nearly all corn and soybeans — though even more land is agricultural since activities like grazing push the total of ag land well beyond 30 million acres. Cropland, woodland and pasture make up so much of the landscape that the category house lots, ponds, roads, wasteland, etc. makes up only 1.4 million acres, or less than 5 percent of the total.
IPP pointed out in a 2010 report Solution to Pollution: It Starts on the Farm that so little land in Iowa is devoted to urban uses (lawns or golf courses) that even if urban application rates of Nitrogen and Phosphorous fertilizer were much higher than that on farms, only 2 percent of the pollution from land application of fertilizer comes from lawns and golf courses.
When sewage treatment plants are included in the urban share of nutrient pollution, agriculture still dominates.
So the take-away message — water pollution in Iowa comes from agricultural land. We all have an obligation to clean up our rivers, lakes and streams and no sector can be exempt — particularly the biggest one. It is not a voluntary matter.