At a time of soaring food prices, America's grocery bill is about to balloon. Congress is staggering toward completion of a nearly $300 billion farm bill that upholds subsidies for big farmers and food corporations – undermining vital efforts to make our food supply more healthful and sustainable, both environmentally and economically.

It's time to overhaul the government's approach to food and farming.

If the current measure passes (as it's slated to this Friday) Americans will shell out billions of dollars for farm subsidies that wreak havoc on our land and diets. These payments irresponsibly promote the consumption of cheap fatty foods, the depletion of soil and air through overuse of pesticides, and destructive farming practices.

Like farm bills past, this one also advances the removal of small farms, eroding the spirit and finances of rural communities across the US.

There is funding for conservation and nutrition programs, even allotments for innovative community food security projects that expand markets for small farmers while making food accessible to poor inner-city residents. But the subsidies for agribusiness – sometimes exceeding $15 billion a year – deepen the very problems these programs seek to remedy.

The core issue lies in the Commodity Title, which subsidizes large growers' production of corn, wheat, and other raw ingredients used in everything from food sweeteners to livestock feed to auto fuel. Supporting farmers to produce basic foodstuffs is a laudable policy, but today's subsidy system instead props up unsustainable growing practices and undermines the nation's health and its farming and food future.

Consider that 75 percent of subsidies go to a handful of commodities (mostly wheat, corn, and oilseeds) used as food additives, making highly processed junk food cheap – while fruits and vegetables and whole foods currently get no aid. Nearly 70 percent of farm subsidies go to the top 10 percent of the country's biggest growers – while America loses one farm every half an hour.

This form of corporate welfare encourages the ongoing consolidation of farming and food production into fewer hands. It removes small and mid-sized farmers who can no longer compete in the unlevel playing field. Meanwhile, by skewing payments toward large-scale farming, these subsidies promote ecologically damaging intensive pesticide use and severe depletion of precious topsoils. Organic foods, often exorbitantly expensive, get no financial support.

As a result, the US dumps nearly half a million tons of toxic pesticides on the land, polluting the air, often sickening nearby residents, and tainting rivers and streams.

Instead of upholding these mega-farm subsidies, let's invest the public's money in sustainable growing practices, organic foods, and small and mid-sized farms that form the bedrock – both economically and socially – of communities throughout America's heartland.

Hardly a romantic nod to the past, such an overhaul is a practical investment in the future. As global warming heats up, we can't afford a system that guzzles 100 billion gallons of oil each year in pesticides and the long-distance transit of packaged foods.

As obesity hits 30 percent of the population – harming lives and costing the public more than $100 billion in related health costs – we cannot afford to finance cheap junk food and excessive meat consumption. And we cannot afford to continue paying large-scale commodity growers to plunder our fast-eroding soils while making it near impossible for smaller diversified growers to compete and survive.

Programs that revive local foods and small farms – via farmers' markets, community-supported agriculture, and school purchasing programs – are gaining ground across the country. Consumers are clamoring for organic foods, and for more farmer's markets where growers can increase profits while keeping food prices the same or lower than in supermarkets.

The public's money ought to finance sustainability in its truest sense – supporting farms and food programs that sustain local economies, our health, and the future of farmlands, instead of agribusiness and food corporations that plumb the land and these communities for short-term profit.

As Congress lurches toward destructive old policies, now is the time to cast our vote for a new path.

Christopher D. Cook, a prize-winning journalist, is the author of "Diet for a Dead Planet: Big Business and the Coming Food Crisis."