Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 28, 2008
Publication Date: N/A
Interpretive Summary: Compacted soils limit crop yields and require some sort of strip-tillage treatments in the Southeastern United States where cotton is typically grown. We found that by using tractors equipped with automatic guidance systems, we could accurately place the crop rows directly over the zones that had been previously tilled. This was possible even though soil was not visible and most crop residue had not been disturbed by the strip-tillage event. Our results indicated that if the cotton row was within 2 inches of the strip-tillage zone, crop yields were maximized. However, if the crop row strayed more than 2 inches away from the strip-tillage zone, crop yields could decline drastically. Site-specific technologies offer many opportunities to increase crop productivity while minimizing energy and fuel waste in agricultural production systems.
Technical Abstract: Producers in the Coastal Plain of the southeastern U.S. manage soil compaction in conservation tillage systems by in-row subsoiling prior to planting. However, planting directly over the loosened zone of soil can be difficult in high-residue conservation tillage systems where cover crop production is maximized. Tractors equipped with guidance systems could assist with placement of in-row subsoiling and planting operations, but little is known about the accuracy necessary to maximize rooting development, reduce succeeding soil compaction, and optimize crop yield. An experiment was conducted in south-central Alabama to determine the maximum distance in-row subsoiling can be from the cotton row without reducing cotton growth and increasing soil compaction. Results showed that if the cotton row is within 5 cm of in-row subsoiling, the relative seed cotton yield is 44% greater than a corresponding no-subsoiling treatment. Recommendations resulting from this experiment indicate that to maximize crop yields and minimize soil compaction in the row, the subsoiled zone should be kept within 5 cm of the row.