Retention of High Levels of Crop Residue on Soil Surface During Tillage

• 1999 annual report
• 2001 annual report
• 2002 annual report

Preservation and improvement of soil quality depends on wise management of tillage. Although no-till, zone-till and less extreme forms of reduced tillage have proven benefits for soil quality, they also pose certain problems. Planting into untilled ground can be difficult, crop growth may be slow due to cold soil in northern climates, and perennial weeds may become problematic. The latter is an overwhelming obstacle to organic producers who cannot use herbicides to kill perennial weeds before planting. Most of the soil conservation problems associated with tillage, however, are not due to tillage per se, but stem from (i) burial of surface crop residues which leaves the soil exposed to erosion and (ii) compaction associated with wheel traffic on freshly tilled soil. Preventing the burial of crop residue during tillage could potentially minimize the first of these problems, whereas the second can be minimized by performing primary tillage and seedbed preparation in a single operation. Single pass tillage implements are becoming increasingly common, but the retention of crop residue on the soil surface during tillage has scarcely been addressed in previous research. We constructed an implement that allows retention of high rates of surface crop residue during tillage operations, and then demonstrated its use in field and vegetable crops. The implement is called the Residue Saver. It chops standing cover crops and picks up surface residue, and redistributes this material behind an attached tillage implement. The device accommodates a broad range of tillage implements. Use of the Residue Saver allows retention of surface crop residue for erosion control and suppression of annual weeds while allowing tillage to facilitate planting, loosen the soil for improved root growth, and destroy perennial weeds. Use of the Residue Saver reduces erosion potential relative to conventional plow tillage and most minimum tillage methods, and reduces herbicide use relative to no-till and some minimum tillage systems. Widespread adoption of the technology could therefore conserve soil, reduce water pollution, and reduce human and wildlife exposure to toxins. It will allow increased use of crop residue for weed suppression, and provide organic producers with a means of retaining surface residue while still tilling the soil. The Residue Saver was tested in 5 trials during the last two years of the project at 3 sites. Two of the three sites were on commercial farms. An extension/outreach program demonstrated the machine at three well-attended field days. One of these was on a commercial farm. Information about the machine, including a digital video clip of the Residue Saver in operation, is available at http://www.css.cornell.edu/weedeco/residuesaver.htm. Further experiments and demonstrations with the Residue Saver are planned for 2004.