Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 30, 2004
Publication Date: November 1, 2004
Citation: Varvel, G.E. 2004. Soil carbon changes in a long-term cropping system study. Agronomy Abstracts # 872941. Technical Abstract: Long-term effects of cropping systems on soil properties, such as organic soil C levels, is necessary so more accurate projections can be made regarding the sequester and emission of carbon dioxide by agricultural soils. A long-term study with 7 cropping systems, (i) continuous corn, (ii) continuous soybean, (iii) continuous grain sorghum, (iv) corn-soybean, (v) grain sorghum-soybean, (vi) soybean-corn-oat+clover-grain sorghum, and (vii) corn-soybean-grain sorghum-oat+clover; with three N fertilizer rates conducted at Mead, NE was used to collect data to help make these types of determinations. Soil samples taken in 1984, 1992, 1998, and 2002 to a depth of 30 cm were analyzed for total C (dry combustion). Results from these samples were used to examine the long-term effects of these cropping systems on soil C levels in the surface 30 cm. Soil C levels as affected by each of the cropping systems and N fertilizer levels during these 18 years will be presented.