Iowa’s future washing down the river

By The Des Moines Register’s Editorial
15 April 2011

The proposed reorganization of Iowa’s Department of Economic Development might be an example of rearranging the deck chairs on the Titanic. However pleasing such a rearrangement might be, it won’t keep Iowa’s economy from sinking.

And Iowa’s economy might well sink if the state doesn’t act soon to avert the loss of its single greatest asset, the thing that made almost everything else in Iowa possible: the soil.

Imagine Iowa with its rich topsoil gone, its fields barren, its rivers and streams choked to death. That is a place in which economic development would cease, no matter how well the DED were reorganized.

Would any business, any person, want to move to a state with washed-out farms and foul streams? Not for all the tax breaks Gov. Terry Branstad can think of.

The specter of Iowa becoming an economic dead zone isn’t some far-out notion. Due to climate change, it’s a plausible scenario.

The possibility of soil depletion has always lurked in the background as a threat to Iowa’s prosperity. Now it has been pushed to the foreground because the rate of soil erosion is accelerating alarmingly.

A recent report from the Environmental Working Group, based on data from Iowa State University, shows that in some recent years soil washed away in Iowa at a rate 12 times faster than nature can replace it, hastening the day when the soil will be completely depleted.

That affirms the earlier report by the Iowa Climate Change Impacts Committee, which was commissioned by the Legislature to study the effects of climate change on the state.

The committee reported that Iowa’s climate has become somewhat warmer and wetter over the last century, but by far the most dramatic change has been in rainfall patterns.

Most floods in Iowa used to occur in the spring, due to snowmelt. Now they tend to occur in the summer, due to heavy rainfall. The number of very heavy rainfalls has grown by more than 30 percent in the last 50 years. Very heavy rains are those that exceed the capacity of the soil to absorb all the water. Those are the rains that cause the most soil erosion.

The climate impacts committee reported that average soil loss in Iowa runs about 5 tons per acre, but 50 tons per acre was lost in some counties in the heavy-rain year 2008. The rate at which soil naturally rebuilds is about 0.5 tons per acre.

The number of heavy rains, and the erosive power of rain, is expected to continue increasing, and the committee pointed out that the resulting damage will increase exponentially. For instance, a 20 percent increase in rainfall causes a 37 percent increase in erosion.

Another effect of a wetter climate is an increase in waterlogged soil. This has induced farmers to install more drainage tile, which speeds the runoff of nitrogen and other farm chemicals into Iowa waterways, where it joins the pollution already brought there by the soil erosion.

Yet another compounding factor is heavy worldwide demand for grain and the resulting pressure on farmers to put every available acre of erodible land into row-crop production.

Soil loss will eventually cause crop yields to decline, causing a severe blow to Iowa’s economy. Yields might be boosted back by dumping more chemicals on the land, but that would further aggravate the water pollution.

The situation has the makings of a perfect storm of environmental degradation in Iowa.

For decades, to Iowa’s shame and detriment, the state’s waterways have been among the most polluted in the nation. For years, the state has dinked around on cleanup efforts, relying on voluntary measures that the farm lobby promised would eventually work.

They haven’t worked, and climate change is making Iowa’s waters dirtier than ever.

It’s time to stop dinking around. Iowa needs to attack soil depletion and water degradation on a scale commensurate with their threat, which is acute.

Iowa cannot change the climate, but it can – and must – try to mitigate its effects, before the soil is gone and the streams are dead.