Soil compaction is a significant problem in many areas in mid-South and Southeastern United States. Most sandy soils of the Southeastern Coastal Plain bear a compacted layer that requires alleviating through costly annual deep tillage operations. Site-specific variable-depth tillage which modifies soil physical properties to the specific depth of compacted layer is of the potential to reduce costs, labor, fuel, and energy requirements. Although technology for site-specific tillage is available, there is a very limited amount of information available on the fuel and energy requirements of variable-depth tillage in southeastern coastal plain soils. Tests were conducted on three types of different coastal plain soils to compare energy requirement of site-specific tillage as compared to uniform-depth conventional tillage operations. Also, the effects of tractor speed, soil texture, moisture content and electrical conductivity on energy requirement and fuel consumption were determined. Energy savings of 50% and fuel savings of 30% were achieved by variable-depth tillage as compared to uniform-depth tillage in loamy sand soil types. Draft force increased as the travel speed increased in all soil types. However, tillage depth exhibited a bigger effect on the draft and drawbar power than the tractor speed. The effect of soil moisture content on draft force and fuel consumption was not significant in either loamy sand or sandy loam soil types. However, draft force and on fuel consumption were in a negative correlation with soil moisture content. Soil EC was highly correlated to soil texture (R2=0.916) as well as draft force all across the field.
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