Author
OMONODE, R - PURDUE UNIVERSITY | |
GAL, A - PURDUE UNIVERSITY | |
Stott, Diane | |
Abney, Thomas | |
VYN, A - PURDUE UNIVERSITY |
Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/15/2005 Publication Date: 2/2/2006 Citation: Omonode, R., Gal, A., Stott, D.E., Abney, T.S., Vyn, A.J. 2006. Short-term versus continuous chisel and no-till effects on soil carbon and nitrogen. Soil Science Society of America Journal. 70:419-425. Interpretive Summary: Although no-till management is widely adopted in the Eastern Corn Belt, and in spite of report of favorable economic returns of no-till, especially for soybean production, cropland in long-term continuous no-till is limited. In practice, farmers often plow their no-till fields, albeit intermittently, before a specific crop in rotation or to correct perceived compaction, pest of soil management problems that may result from long-term no-till. The objective of this study was to determine the effects of intermittent tillage systems on organic carbon (C) and total nitrogen (N) relative to continuous no-till and chisel plow systems. A field experiment was initiated in 1980 to study the effects of continuous no-till (NT), continuous chisel plow (CP), and moldboard plow in continuous corn and soybean-corn rotations. In 1996, the moldboard treatments were split into two subplots. One subplot was converted to no-till (Int-NT) while the other was intermittently chisel-plowed (Int-CP) every year, or in alternate years (before corn in the soybean-corn rotation). The Int-CP was chisel plowed before corn (every year, every two years or every three years depending on the rotation system). Int-NT was left untilled for all crops in sequence. After crop harvest in 2003, soil samples were taken incrementally to a one meter (39.4 inches) depth from NT, CP, Int-NT and Int-CP plots. Soil C and N accumulation was unaffected by rotation system (continuous corn, corn-soybean rotation, and corn-soybean-winter wheat) at any depth interval. However, tillage treatments significantly affected soil C and N concentrations in the top 50 cm (19.6 inches). In the 0-5cm (0-2 inches) depth interval, C concentration was higher in NT than all other tillage systems while total N concentration was higher in NT than CP and Int-CP systems but not different from Int-NT. On equivalent soil mass basis, C storage after 24 years totaled 150 Mg per hectare (70 tons per acre)in continuous NT, or 26% more than in continuous CP. Int-NT and Int-CP systems resulted in 25 and 19 Mg per hectare (11.1 and 8.5 tons per acre) more carbon, respectively, than CP, suggesting that the combination of moldboard plowing (17 years) followed by short-duration (up to 7 year) no-till or chisel was superior to continuous chisel plowing. The impact of this work includes enhanced understanding of the effect of current land management practices on soil carbon sequestration allowing for improved recommendations to farmers and land managers. Technical Abstract: For various management reasons, North American crop farmers are more likely to practice limited-duration no-till than continuous no-till. Previously no-tilled soils may be plowed intermittently. Little is known about effects of short duration no-till on organic carbon (C) and total nitrogen (N) relative to continuous no-till and conventional-till systems. A field experiment was initiated in 1980 to study the effects of continuous no-till (NT), continuous chisel plow (CP), and moldboard plow in continuous corn and soybean-corn rotations on dark prairie soil. In 1996, the moldboard treatments were split into a short-term no-till (ST-NT) subplot and an intermittently chisel-plowed (STI-CP) sub-plot that was chiseled only before corn. In 2003, soil samples were taken incrementally to 1.0 m depth from NT, CP, ST-NT and STI-CP plots. Soil C and N accumulation was unaffected by rotation system at any depth interval. Tillage treatments significantly affected soil C and N concentrations only in the upper 50 cm. On an equivalent soil mass basis, C storage to 1.0 m after 24 years totaled 150 Mg ha^-1 in continuous NT, but just 110 Mg ha^-1 in continuous CP. ST-NT and STI-CP systems resulted in 25 and 19 Mg ha-1, respectively, more soil C than CP. Total N storage was similar for NT and ST-NT systems, but significantly lower (3 Mg ha^-1 less) with CP. Our results suggest that the combination of moldboard plowing (17 years) followed by short-duration (6-7 year) no-till or chisel was generally superior to continuous chisel plowing (24 years) in soil C and N contents. The impact of this work includes enhanced understanding of the effect of current land management practices on soil carbon sequestration allowing for improved recommendations to farmers and land managers. [GRACEnet Publication] |