By Curt Zingula
The hot-button concern about the Iowa Nutrient Reduction Strategy is voluntary participation. But like any project, leadership will be the difference between success and failure. So far, leaders are stepping up to the plate.
Strategy must distinguish between what does and doesnít work. The Iowa Department of Natural Resources, Iowa State University and the Iowa Department of Agriculture and Land Stewardship are in agreement that a one-size-fits-all regulatory approach would be like trying to use a Band-Aid for a severed foot ó better than nothing, but leaving much to be desired.
Farming practices and land differ considerably across Iowa. Scores of different soils, topographies, fertilizers, tillage and cropping systems donít lend themselves well to one-size-fits-all regulations. Throw in weather extremes, and the task of reducing nutrient runoff becomes monumental.
Many farmers are adopting technology to manage fertilizer. Variable-rate technology uses GPS and fertilizer trucks with onboard computers to apply fertilizer according to the soilís fertility test results. The same can be done when soil-incorporating manure slurries from livestock confinement facilities.
Phosphorous leaves my farm primarily by erosion as an attachment to soil molecules. I manage this in two ways; by reducing tillage, which leaves more protective crop residue on the surface, and by using subsurface drainage, which allows more rain to be absorbed into the ground.
Reducing nitrogen pollution will be a much greater challenge. Nitrogen fertilizer is broken down by soil bacteria into unstable forms such as nitrates. Seasons characterized by heavy rainfall will spike nitrate runoff even with government intervention. In addition, nitrates occur naturally in water due to the decomposition of organic matter, such as leaves and aquatic vegetation.
In my farming operation, I knife-in nitrogen during late fall on soybean stubble and accompany it with a bacteria inhibitor. By spring, the ground disturbance is negligible, and I can plant corn directly into those fields without tillage. Increasingly, other farmers are choosing to spend time on splitting their nitrogen applications in order to minimize the loss of that nutrient to adverse weather.
Filtration beds filled with wood chips and located at the outlet of subsurface drainage lines are effective for reducing nitrates. However, requiring landowners to install filtration beds would ignite a firestorm of conflict over who foots the bill when drainage lines traverse multiple properties and most were never recorded.
Post-harvest cover crops rapidly are gaining farmersí attention. Cover crops have the potential to improve soil health and retain nitrogen for future crops. The challenge will be to convince farmers that cover crops can help pay their bills. So far, the subsequent yields Iíve read about have been less than convincing, but seasoned cover crop users point out that experience will lead to success.
Itís widely recommended that farmers use CRP vegetative buffer strips to filter nutrient runoff. The problem with depending on CRP is that neither Congress nor President Barack Obama see the need to maintain budgets for agricultural conservation programs. On the other hand, government could enhance voluntary conservation by offering significant tax incentives for conservation-qualifying tools in the same regard as they do for energy-saving building materials.
Voluntary change must deal with mindset. Regulations alone will fall short of the Environmental Protection Agencyís goals without greatly multiplying administration and subsequent policing ó jobs that already struggle to obtain funding for other environmental priorities.
Whichever route farmers choose, the changes will be the most dramatic since horsepower arrived on wheels.Curt Zingula grows 1,285 acres of corn and soybeans along with a 20-acre tree farm in Northeast Linn County. He is a recipient of the Iowa Farm Environmental Leaders award. Comments: firstname.lastname@example.org