Hillary Rodham Clinton proposed banking and tax changes Wednesday that she said would encourage investment in agriculture and rural businesses, along with expanded federal assistance for farmers and ranchers.

With a backdrop of a gleaming John Deere tractor at an Iowa community college, Clinton presented a network of initiatives that would build on existing support programs for agriculture, rural development and education. Some elements of Clinton’s rural program, such as her proposals to make public college education more affordable, have been released previously.

The Democratic front-runner’s rural aid package contains an endorsement for ethanol, the corn-based fuel additive. Iowa is the world’s largest producer of ethanol, which is at the center of an environmental and resources debate about the expense and efficiency of growing corn for fuel instead of food.

A fact sheet provided by Clinton’s campaign ahead of her speech says she would “strengthen” the federal Renewable Fuel Standard to promote development of advanced biofuels and improve “access” to ethanol products called E15 and E85. The plan does not state how this would be done and does not address the food vs. fuel environmental debate, although it follows the section on biofuels with bullet points on Clinton’s clean energy program.

The plan envisions expanded tax credits and grants for rural communities and more help for young farmers to help them start businesses or retain family farms. The campaign did not spell out how Clinton would pay for the additional help, nor did it discuss the prospects for getting congressional approval for some elements of the plan.

"Too many young people feel they have to move away," to find jobs and build lives, Clinton said at the Des Moines Area Community College.

"It's imperative that we have a comprehensive agenda to revitalize rural America," Clinton said. She said she wants to expand the share of the nation's energy supply that comes from renewable fuels.

She proposes expanding access to capital for rural businesses though an existing program run by the Farm Credit Administration and new, simpler regulations for community banks that would speed loans to farms and rural businesses.

The Republican National Committee called the plan "unserious."

The only thing clear about Hillary Clinton’s proposal is that she wants Washington to spend even more money with no plan to pay for it," said RNC spokeswoman Allison Moore.

Clinton pledges to invest in rural business and infrastructure, including expanding tax credits and grants available to those communities. Money to help farmers who are starting out and for farmers markets and local foods would be doubled under her plan.

She is spending the day in Iowa, site of the nation’s first presidential selection contest and a crucial test of Clinton’s strength as the Democratic primary becomes more competitive. Sen. Bernie Sanders (I-Vermont), a Democratic challenger, has eroded Clinton’s lead in Iowa to less comfortable margins. Meanwhile, the possibility that Vice President Biden might enter the race may give Clinton new reason to worry.

Iowa has been the principal focus on Clinton’s nearly 6-month-old campaign, largely in recognition of the damage done by her third-place finish there in 2008. After losing that nominating contest, Clinton has built the largest campaign operation of any candidate in either party and the largest branch operation in Iowa.

Although agriculture is a major part of Iowa’s economy, most of Clinton’s campaigning in the state has been in urban centers. More than a third of Iowa residents live in rural areas.