Farmers have choices for how they prepare the soil; reduce weed growth; incorporate fertilizer, manure and organic matter into the soil; and seed their crops, including the number of tillage operations and tillage depth.

Tillage practices affect soil carbon, water pollution, and farmers' energy and pesticide use.

No-till is generally the least intensive form of tillage.

Approximately 35 percent of U.S. cropland (88 million acres) planted to eight major crops had no-till operations in 2009, according to ERS researchers who estimated tillage trends based on 2000-07 data from USDA's Agricultural Resource Management Survey (ARMS).

Furthermore, the use of no-till increased over time for corn, cotton, soybeans, rice and wheat, the crops for which the ARMS data were sufficient to calculate a trend.

While a more recent estimate of nationwide use of no-till by all major crop producers is not available, based on the results of recent surveys of wheat producers in 2009 and corn producers in 2010, it seems likely that no-till's use continues to spread, albeit at a much reduced pace among corn producers.