SIMPLE PRACTICES… BIG IMPROVEMENT – Page 3
In large areas of Iowa and the Corn Belt, the erosion and runoff problem is complicated by the practice of burying miles and miles of pipes, generally called “tiles,” three or four feet below the soil surface. These tiles drain water from the soil and send it to larger and larger pipes that eventually send surface water into a stream or ditch. Tile drainage has turned millions of acres of poorly drained soil into some of the most productive corn- and soybean-growing land in the world, but it short-circuits the normal filtering process that occurs when water percolates through the soil. As a result, the water can carry off very large amounts of pollutants, including fertilizers, pesticides and bacteria.41
Today’s farming practices have helped reduce soil erosion with tillage practices that leave more cover on large, modern-day crop fields. In the first half of the 1900s, every farmer had livestock that required pastures, hay land and fences around all fields. These fences acted like terraces, and the forage crops helped hold the water on the land. Now, fences and small fields are obsolete; large fields are the norm, creating serious soil erosion possibilities.
What can we as farmers do about lessening this possible catastrophe? There are a number of appropriate conservation practices that we can use, but filter strips along waterways, whether big or small, are absolutely essential, in my mind. Such strips are a wonderful way to control the speed of water as it leaves a field, and the water is filtered before it enters our creeks and larger waterways. These grassy strips are also very advantageous for wildlife, which is searching for just such a place to live and rear its young. It is critical that we maintain and increase the number of these filter strips in our rural areas, and it is also critical that our federal and state governmental agencies make it economically feasible for farmers and others who own the affected agricultural properties to use the practice.
Ted Schutte, Sibley, Iowa Farmer
Most important, tile drains can defeat some of the pollutant filtering benefits of buffers by sending runoff water beneath, rather than over and through, the strips.42 The problems caused by tile drainage have received a great deal of well-deserved attention, particularly in regard to the delivery of nitrogen that contributes to the dead zone in the Gulf of Mexico.43
Sometimes lost in a conversation that has focused so intently on the special problems of tile drainage is the profound role that surface runoff and erosion play in degrading streams, lakes, and rivers in the Corn Belt. Water that falls on cropland has only two places to go. It can percolate into the soil or run over the soil surface. In big storms that produce intense rainfall, much or most of the rainfall flows over the soil, even on cropland underlain with tile drainage systems. Such intense storms that seriously erode soil deliver huge volumes of polluted runoff to lakes, streams, and rivers and cause lasting damage to agricultural watersheds.
Unprotected cropland and unbuffered streams deliver a one-two punch to the soil, to watersheds and to waterways. The scientific literature and practical experience make it clear that simple, sound and highly effective practices are available today that would make a big difference in gaining ground in the fight to reduce soil erosion, polluted runoff and watershed degradation.
The problem is not primarily a technical one. It is a problem of poor policy and institutional inertia.