A polluted stream which has turned white in Dongchuan district of Kunming, Yunnan province, March 20. According to local media, the source of the pollution is waste water discharged by nearby mining industries.

Farmers dig ditches from a white polluted stream to farm fields for irrigation in Dongchuan district of Kunming, Yunnan province, March 21.

A villager carries buckets of water to be used for drinking from a white polluted stream in Dongchuan district of Kunming, Yunnan province, March 20.

A villager holds two bottles of water, one from the polluted stream, left, and the other normal mineral water, in Dongchuan district of Kunming, Yunnan province, March 21.

First grade student Livie Classenn recites the Pledge of Allegiance to start the day at the Walton Rural Life Center Elementary School, in Walton, Kan., Jan. 18. Students at the school do farm chores at the beginning of each school day. The Walton Rural Life Center - a kindergarten through fourth grade charter school in rural Kansas - uses agriculture to teach students about math, science, economics.

Third-grade students Cody Eye and Elizabeth Harder feed the hogs.

First-grade student Destiny Smith prepares hay to feed the cows.

Workers spread out the freshly picked Oolong #17 tea leaves on a screen for drying.

Labourers sort through and grade harvested tomatoes on a farm that supplies fresh produce to Wal-Mart in Narayangaon, about 112 miles west of Mumbai.

Labourers harvest tomatoes on a farm that supplies fresh produce to Wal-Mart in Narayangaon.

Two-wheelers move past the newly opened Bharti Wal-Mart Best Price Modern wholesale store in the southern Indian city of Hyderabad.

Workers walk inside an aisle of the newly opened Bharti Wal-Mart Best Price Modern wholesale store.

Farmer Justin Waddington, foreground, repairs a combine during a wheat harvest in Washington state's Yakima Valley. Growers in the Pacific Northwest are benefitting from high prices created by the drought affecting the Midwest. Waddington grows corn, wheat and alfalfa. According to him, as the price of corn spikes, as it's doing now with the drought, wheat and soybeans follow because farmers substitute the other grains in animal feed.

Waddington watches newly harvested wheat pour into a truck in Washington state's Yakima Valley.

Smoke billows from a barn with hogs inside it on Monday. The location is west of Reinholds, Pa. in West Cocalico Township. Multiple fire companies in northern Lancaster County responded.

Hogs walk in front of a Denver firefighter as he directs water on a structure blaze at a West Cocalico Township farm in northern Lancaster County on Monday. It is not yet known if all livestock survived the fire as multiple companies responded to the alarm.

Marisol Brito cuts hop vines at the base as she works harvesting hops at the Puterbaugh Farms in Mabton, Wash. Aug. 30, 2011. Once the vines are cut, a combine follows her and completes the harvest process.

Josh Frank distributes hops as they're dumped into a truck following a harvesting combine Aug. 30, 2011 at the Puterbaugh Farms in Mabton, Wash. The hops being harvested are the Columbus variety and may be sold to a hops merchant or directly to a brewery or brewer through the website hopsdirect.com.

Steve Walthart brings hay to his cows at his farm just down the road from Independence in the bordering town of Winthrop, Iowa on July 6. Walthart farms corn, soybeans and hay on 560 acres outside Independence. With farmland prices in Iowa now fetching $8,000 or more an acre, he is sitting on a gold mine if ever he decided to sell out, but Walthart dismisses the idea of cashing out and retiring.

A classic car is parked in the driveway at Steve Walthart's home. "Think of it, think of it," he said, "what would I do with the money? There's no better place to have it than where I've got it --in the farmland." He says he expects he will die doing his daily chores.