Submitted to: Journal of Cotton Science
Publication Type: Proceedings
Publication Acceptance Date: August 28, 1997
Publication Date: N/A
Interpretive Summary: Coastal Plains soils require periodic tillage to alleviate soil compaction and hardpans impervious to proper root growth. It was hypothesized that eliminating traffic from field plots would result in reduced soil strength throughout the rooting zone. After 5 years of using a spanner-type vehicle to eliminate field traffic, an assessment of soil strength was conducted to determine differences attributed to traffic and tillage treatments. Traffic was found to reduce the available growing zone for plants, but did not greatly restrict the rooting depth immediately beneath the row when annual in-row subsoiling treatments were used. This result proved that a similar soil condition beneath the row was obtained by adopting the conservation tillage system of annually in-row subsoiling and planting as was obtained by totally eliminating traffic with a spanner-type vehicle.
Technical Abstract: Extensive cone index measurements were used to evaluate the soil condition resulting from five years of a cotton (Gossypium hirsutum L.)-whe riticum aestivum L.) double cropping experiment. Four cotton tillage systems including a conservation tillage practice of in-row subsoiling and planting into wheat residue stubble and two traffic systems were analyzed. The USDA-ARS Wide-Frame Tractive Vehicle (WFTV) was used to control traffic in the experimental plots. Contour graphs of cone index were used to determine differences in tillage and traffic systems. Traffic was found to reconsolidate soil that was initially completely disrupted to a 0.51-m depth into a soil condition similar to one that had never received a subsoiling treatment. Traffic was also found to decrease the total soil volume estimated for root growth using a 2 MPa limiting cone index value, but not the maximum rooting depth beneath the row, when an annual in-row subsoiling practice was used.