Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 21, 2001
Publication Date: N/A
Technical Abstract: High strength within subsurface horizons requires that deep tillage be performed for many Coastal Plain soils to provide a suitable rooting environment. We measured soil strength (cone indices) in treatments that were deep tilled annually or semiannually, in the case of double cropping, to examine recompaction. Cone indices were measured from 9 days to 6 years after tillage, with rainfall amounts between tillage and measurement ranging from 0 to about 6800 mm. Measurements were made at the point of maximum disruption by a paratill which disturbed soil to 35-cm to 40-cm depths. Regressions of cone indices with rainfall showed that recompaction was still taking place at the end of the experiment. Recompaction was slower than expected probably because of controlled traffic or excessive disruption by the paratill. Recompaction, at least temporarily, was greater for the 10-cm to 20-cm depths when compared to the 25-cm to 35-cm depths. Though recompaction was slow, tillage would still be necessary annually or seasonally because even with incomplete recompaction, yield-reducing soil strengths built up after a year or less.