Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 29, 1997
Publication Date: N/A
Technical Abstract: Conservation tillage can improve soil chemical, physical, and biological properties of previously cultivated soils. We determined soil organic C, soil microbial biomass C, mineralizable C, particulate organic C, and water-stable aggregation at depths of 0-2.5, 2.5-7.5, and 7.5-15 cm from a kaolinitic Alfisol located in the Southern Appalachian Piedmont of Georgia. Millet (Panicum miliaceum L.) with a clover (Trifolium incarnatum L.) cover crop was seeded during the first two years and cotton (Gossypium hirsutum L.) with a rye (Secale cereale L.) cover crop was seeded the next three years. Soil tillage treatments were a factorial arrangement of tillage type (zero tillage with an in-row chisel at planting, zero tillage planting with autumn paraplow, and zero tillage planting with secondary tillage during the summer) and tillage frequency (every year, every second year, and every fourth year). When soil disturbance occurred every year, soil biochemical properties deteriorated. The two to three fold increase in organic C and N fractions that developed at a depth of 0-2.5 cm was important in improving crop yield, in part due to biophysical impacts on surface soil structure and water infiltration.