GOP presidential prospects _ few with dirt under their nails _ to talk agriculture in Iowa

It seems like a no-brainer for prospective presidential candidates: Come to Iowa to talk about agriculture. Thing is, not many of them do anymore and few can boast having dirt under their fingernails.

A Republican donor with both money and influence is forcing the issue. On Saturday, Bruce Rastetter will put nearly a dozen likely candidates for president through their paces on the price of corn, water quality and other concerns rooted in the land.

"There is no industry that touches more Americans every day than agriculture," Rastetter said.

Unlike other "cattle calls" of the 2016 prospects, Saturday's event isn't a series of speeches — it's Rastetter's show. The businessman plans to lead a discussion with each about issues that are dear to Iowa farmers but affect everyone. They also happen to be topics that have faded from campaign talking points in Iowa over several elections.

Republican Gov. Terry Branstad, co-host of the forum in Des Moines, says "total ignorance of agriculture" just won't do in a potential president. Given the enduring if challenged prominence of Iowa in presidential politics, thanks to its curtain-raising caucuses, ignoring the state won't do, either.

Iowa leads the nation in corn, soybeans, pork and egg production. It also produces more ethanol, a fuel additive made mostly from corn, than any other state, and ranks third nationally in the production of wind-generated electricity. But the farm is far from the daily lives of most voters and, perhaps as a result, increasingly distant from the concerns of many who want to lead the nation. The Iraq war dominated Democratic caucuses in 2004; eight years later the GOP race in Iowa centered on the staggering economy.

The event features the return of former Arkansas Gov. Mike Huckabee and former Pennsylvania Sen. Rick Santorum, winners of the past two GOP caucuses but losers for the nomination. Also expected: former Florida Gov. Jeb Bush, New Jersey Gov. Chris Christie, Texas Sen. Ted Cruz, former Virginia Gov. Jim Gilmore, South Carolina Sen. Lindsey Graham, former New York Gov. George Pataki, former Texas Gov. Rick Perry, businessman Donald Trump and Wisconsin Gov. Scott Walker.

Topics that might come up:

RENEWABLE FUEL STANDARD

The government in 2013 proposed reducing the biofuels required to be blended into gasoline. The move would, for the first time, roll back the Renewable Fuel Standard, which calls for annual increases in the minimum amount of renewable fuels such as ethanol. Leaders from both parties in Iowa say that would devastate the state's economy. The government proposed the step because of higher fuel efficiency in new automobiles.

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IMMIGRATION

Iowa's pork and egg production relies heavily on immigrant labor. Over the years several Iowa meatpacking and egg production operations have been cited for employing immigrants in the country illegally. The issue points to differences among the emerging candidates on immigration, most notably Bush, who supports a pathway to legal status for such immigrants as an economic engine, and Walker, who supported the same position as Bush before changing his mind recently.

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FOOD PRODUCTION

In 2011, the world population reached 7 billion and is projected to increase by 1 billion in the next decade. The globe has absorbed rapid rises in population since the 1950s. However, strains are intensifying in the developing world, especially on food and energy costs. Roughly 1 billion people are undernourished worldwide. This plays into Iowa's status as the world leader in corn, soybeans, pork and eggs. It also has an emerging fish-farming industry.

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WATER QUALITY

Some Iowa farmers and interest groups have complained that the Environmental Protection Agency has overreached its authority in applying the Clean Water Act. They argue they are being unfairly regulated and face higher costs for environmental testing and permits for smaller waterways or ponds on their property. Midwestern farm states, especially Iowa, face pressure to reduce the amount of nitrogen, chiefly from crop fertilizer, entering waterways. Runoff from Iowa farm land has been a chief contributor to the dead zone, where nutrient pollution disrupts marine life, in the Gulf of Mexico.

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BIOTECH

Agricultural interests oppose efforts to label genetically modified food and could be forced, under legislation in Congress, to abide by national standards regulating the technology found in much of the U.S. food supply. The vast majority of food processed in the United States contains genetically modified organisms, or GMOs. GMO labeling efforts have failed in states where consumers have rejected the added cost of food from additional testing and regulation of ingredients.

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