On the supply side, farmers are faced with spreading water shortages, a scarcity of new cropland to plow and the ongoing loss of cropland to residential construction, industrial construction and the paving of land.
These were among the report's recommendations: *Increase the yield on existing cropland to reduce the need for clearing additional forest.
The same incentives have landowners clearing steep hillsides or converting pasture to cropland to cultivate or rent out.
By Ian Frazier Vertical farming can allow former cropland to go back to nature and reverse the plundering of the earth.
One analysis published in the journal Global Change Biology showed a 19percentt increase in soil carbon after land changed from cropland to pasture.
Irrigation became necessary as population pressure forced cropland to be expanded, and irrigation works were constructed in many states beginning in the late Chunqiu period.
The bottom line is that water constraints – augmented by soil erosion, the loss of cropland to nonfarm uses, a plateauing of yields in major producing areas, and climate change – are making it more difficult to expand world food production.
Senate leaders have just begun to write a farm bill, which they say will place greater emphasis on conservation, like paying farmers to return cropland to prairie, which would not violate trade agreements.
Government officials say reaction to the drought has been swift, and they denied that there had been an exodus of farmers from parched cropland to the cities, where they could search for jobs.
Andy Prosser, the public relations director of the Mississippi Department of Agriculture and Commerce, said that he expected more than 500,000 acres of cropland to be flooded throughout the delta if current projections hold.
Replacing all US ethanol (biofuel) production with algae oil would need around 2m acres of desert, but, says Arizona State university professor Mark Edwards, it would potentially allow 40m acres of cropland to be planted with human food, and save billions of gallons of irrigation water a year.
