A new USDA report entitled, "The Changing Organization Of U.S. Farming" points to crop-residue management and reduced-tillage practices as a major trend heading into the future.

The agency says that in 2004, farmers practiced crop-residue management (CRM) on roughly 172 million acres (62% of planted acres), up from 142 million acres in 1989 (51%).

CRM is defined by the USDA as maintaining additional crop residue on the soil surface through fewer and/or less-intensive tillage operations.

CRM includes reduced tillage, conservation tillage such as no-till, ridge-till and mulch-till), and the use of cover crops and other conservation practices that leave sufficient residue to protect the soil surface from the erosive effects of wind and water.

Conservation tillage accounted for 41% of U.S. planted crop acreage in 2004 (the most recent data available), compared with 26% in 1989, the USDA says.

"The expansion of conservation tillage has come entirely from the adoption of no-till, which increased from 14 million acres in 1989 to nearly 63 million acres in 2004," the report says, adding that economic factors, government policies and programs and technological innovation are all driving the expansion of no-till.

The development of larger and faster equipment, information and GPS technologies, and precision agriculture tools such as yield monitors and variable-rate equipment allows farmers to better match seed, fertilizer, and pesticide applications to areas within a field where they are most needed," the report says.

"The development of genetically engineered seeds and adoption of crop varieties with herbicide tolerance (HT) and/or resistance to specific pests (Bt) has facilitated a shift to less intensive tillage systems, particularly no-till."