Abstract
Conservation tillage practices promote soil environmental conditions that may enhance carbon (C) sequestration in agricultural soils. However, the exact nature and magnitude of this effect is not fully understood. The goal of our study was to examine the ability of two forms of conservation tillage (no-till and chisel plow) to sequester C over a 12-year period. In addition, the relationship between soil organic C, root distribution and the general growing environment was determined in each tillage system. Greater root density and similar yields suggest that the measured increase in acidity is not having a negative impact on crop productivity or C inputs under NT. While there was a trend for greater C stocks under NT as opposed to CP, differences were not significant after 12 years. Greater C inputs under NT and similar C stocks suggest redistribution and greater loss of C as carbon dioxide and/or dissolved organic C under no-till as opposed to chisel plow. Carbon is highly variable on a field scale due to soil-landscape relationships and tillage influences. Variability of C presents challenges to obtaining representative samples to growers who are interested in measuring C stocks in their fields for either C credits or as means of assessing the impact of their management practices on soil quality. Growers interested in determining soil C stocks need to consider topographic variables such as aspect, slope percentage and landscape position.