A couple of recent newsletters from Sen. Tom Harkin define a tricky intersection that Iowa is now approaching.

In one, Harkin extols the virtues of  the Conservation Security Program,  which is the government's effort to  take cropland out of production and  increase wildlife habitat at the same  time."I am committed to expanding the  program to every part of our state so  that every farmer has the opportunity  to enroll," Harkin wrote."This will help  to improve water quality and wildlife  habitat for all Iowans."

Sounds good.But then there's ethanol.

Harkin is chairman of the Senate  Agriculture, Nutrition and Forestry  Committee, which puts him in the middle  of writing the next farm bill. "As  chairman ... I intend to use the new  farm bill as the vehicle for a dramatic  ramping up of the production, distribution  and consumption of biofuels and  other forms of renewable energy," he  said in the other newsletter.

Another admirable goal in terms of  Iowa's economic fortunes.

But when we start to get serious  about increasing our corn and soybean  crops, that conservation ground is  going to look awfully tempting.

If we start driving into those grassy  areas with herbicides and chisel plows,  it's not just the pheasant hunters who  will be affected. We'll start eating into  our stockpile of topsoil faster than ever.

And if we throw every available  kernel into ethanol production, it  won't be just the tortilla buyers in  Mexico who are affected by the  increase in prices. First the livestock  farmers will notice that feed is getting  more expensive, then the non-farmers  will notice the same about food for the  dinner table.

We're committed to building an  ethanol industry, so let's be aggressive.  But the path seems to wind through a  lot of problematic consequences, so  let's keep looking for better routes.

Based on what we know so far, it  seems wise to put a substantial amount  of time and money into studying the  cellulosic ethanol possibilities. Environmentally and maybe economically,  switchgrass and the like might be a better  bet than corn.