ABSTRACT
Conservation tillage is a broad term used to dene any tillage system that has as its primary objective reduction of soil and water losses. ¤e primary reason, however, why farmers in many U.S. regions change from conventional tillage (CT) to some form of CS is to reduce farm input costs and to increase prots (Smart and Bradford, 1996). Secondary reasons include soil and water conservation and insulation of the soil surface from temperature extremes. ¤e use of CS reduces tra¬c operations, thereby decreasing soil compaction and costs for labor, fuel, tractors, and other equipment. In some cases, however, costs are increased because herbicides cost more than the tillage they replace. Even so,
25.1 Introduction ...........................................................................................................................25-1 25.2 Denitions ..............................................................................................................................25-2 25.3 Erosion by Water and Wind .................................................................................................25-3
Erosion by Water • Erosion by Wind 25.4 Water Conservation...............................................................................................................25-5 25.5 Residue Management and Decomposition ........................................................................25-7 25.6 Biological Activity .................................................................................................................25-8 25.7 Carbon Dynamics and Sequestration in No-Tillage ........................................................25-9 25.8 Biofuel (Cellulosic) Production Implications ..................................................................25-11
25.10 Surface Sealing, Crusting, and Seedling Emergence .....................................................25-16 25.11 Compaction ..........................................................................................................................25-17 25.12 Cropping Systems ................................................................................................................25-18 25.13 Cover Crops ..........................................................................................................................25-20 25.14 Comparison of Conservation Tillage with Conservation Agriculture .......................25-20 25.15 Soil by Climate Interactions ...............................................................................................25-21
25.16 Disadvantages .......................................................................................................................25-22 25.17 Conclusions...........................................................................................................................25-23 References .........................................................................................................................................25-23
farmers oen adopt the new technology because yields increase at a faster rate than the costs (Bradford and Peterson, 1999).
