In my local newspaper column, I harp and carp about what I think is an overuse of farm field tile drains. Our local Ohio farming depends heavily on tile drainage for good crops so being critical of it is precarious. But now there is an uproar in Iowa indicating that perhaps I’m not so far off base. For those of you unfamiliar with tight clay soils, drainage systems using clay or concrete tile or now mostly plastic, to carry the water away underground, are necessary for profitable yields if the land is to be kept in a high state of cultivation. Surface water seeps down through the soil into the tile system and is funneled away into creeks and ditches. Without such drainage, the soil would “lay wet” too long in spring and after rains. Much of this kind of soil is very fertile, so it pays to drain it. In earlier years, just the wettest areas of fields were tiled. (I’ve told this story before but can’t help it. As a child I watched my grandfather digging ditches and installing clay tile by hand. He said the water coming out of a tile outlet was good for a body, especially when it carried little particles of iron rust in it. Then one day he noticed that some of those specks of rust wriggled.) Today, whole fields are crisscrossed systematically every 50 feet or so with tile about two to three feet underground. The result is that after heavy rains, the water flushes out faster, creeks and rivers overflow faster, and flooding on country roads and on city streets seems to be worse although how much of this can be blame directly on tile is disputed. One result that I find almost amusing is that on rural roads drifts of cornstalks now float out of the fields after heavy rains. Worse than snow drifts.
Now, in Iowa, another problem is being blamed on tile. The water used by Des Moines has nitrate levels running too high, 30 milligrams per liter where the safe drinking level is put at 10 mpl. The Des Moines Waterworks has filed suit against 10 Raccoon River watershed districts, seeking monetary damages under federal law to help build new filtering systems to render the water safe. Des Moines claims that the problem is stemming from extensive tile drainage systems installed in recent years. That is a truly new development. Like my grandfather, most farmers have always believed that when rainwater filters down through soil into the tile drains, it comes out almost as pure and undefiled as holy water in a Baptismal font. Now it appears this water, with or without “rust specks,” is carrying in it dangerous concentrations of nitrates. Historically, government regulations have agreed with grandfather. Tile drainage is a good thing so tile outlets just can’t be point sources of pollution, perish the thought. So battle lines are drawn. I hear that the same issue is being raised in parts of Illinois where extensive tile drainage systems are also going in hand over fist.
I have a hunch that Des Moines will win and farmers are going to have to help cities pay for cleaner water. Maybe that’s fair. And if farm size keeps going up, who is going to protest if a 50,000 acre executive farmer has to pay.
But it seems to me that urban areas ought to work into their nitrate equations the amount of fertilizer that is coming from lawns. (Maybe they do.) How many millions of acres of lawns are being saturated with fertilizer to no purpose but the satisfaction of homeowners or factory owners who like to keep nice meadows around their buildings. Or if you really want to get a bad pollution headache, how many millions of septic tanks are not functioning correctly and contributing to the nitrate problem? And how much more nitrogen and phosphorus can be removed from treated city waste water if the money was committed to doing it? Life is just too complicated. But at least there is a way to lessen nitrate runoff from farmland. Grow less corn for piston engines to drink and put that land into more legumes. That would decrease the amount of nitrogen fertilizer needed and provide a whole lot more environmentally friendly hay and grass for livestock.
Here in Ohio our lakes, including Lake Erie, are being overrun with polluting algae from too much nitrogen and phosphorus in the runoff water. Spreading animal manures improperly on the land is considered one of the main culprits, not tile water. I wonder exceedingly. There are surely fewer farm animals in Ohio now than there was eighty years ago when thousands of little farms all kept animals. There were no polluting algal blooms on our lakes then. What if the real problem is water seeping down into the tile from fertilizers injected into the soil, which are exempted from the new runoff laws.