Excerpt
No-till or direct seeding practices were used on 20.1 million hectares in the U.S. in 2000 (CTIC, 2000). Compared to conventional tillage, no-till systems provide several benefits including reduced soil erosion and offsite sedimentation and increased fuel and labor efficiency. More recently, no-till systems have been shown to significantly reduce short-term carbon dioxide emissions offering potential for reduction of greenhouse gas production if adopted over significant cropland acreage (Allmaras et al., 2000). In the United States, use of conservation tillage systems alone can account for nearly half of the carbon sequestration potential of improved management of cropland (Lal et al., 1998). Studies suggest, however, that short-term improvements in carbon stocks are lost when growers rotate no-till systems with conventional tillage systems that retain little residue cover on the soil surface after planting is completed (Lindstrom et al., 1999; Reicosky et al., 1995).
Alternating or rotating tillage systems among crops can also affect yield and soil properties. In Minnesota, Randall et al. (1996) evaluated rotational tillage for corn (Zea mays.) and soybean (Glycine max (L …
Footnotes
Peter R. Hill is an agronomic systems manager with Monsanto.
- Copyright 2001 by the Soil and Water Conservation Society