Long-term Tillage: Effects on Soil Carbon, Nitrogen, and Yield; University of Nebraska Lincoln

The experiment has a randomized plot design. There are control plots described as follows: Native sod plots serve as the controls. These plots have not been grazed so plant composition has changed.

Staff recently implemented a 5 year burn schedule to return the plots to a more native state. Average climatic conditions at the experimental site: Minimum annual temperature: -3.9 deg C Mean annual temperature: 9.1 deg C Maximum annual temperature: 22.6 deg C Minimum annual rainfall: 230 mm Mean annual rainfall: 440 mm Maximum annual rainfall: 520 mm Soil properties at the experimental site: Depth of root limiting layer: No root limiting layer Approximate soil organic matter content: 2.3% Approximate carbon:nitrogen ratio: 12.4 Approximate soil bulk density: 1.1 g/cm3 Percent clay (i.e. particles less than 2 um): 23% Percent silt (i.e. particles between 2 um and 50 um): 37% Percent sand (i.e. particles between 50 um and 200 um): 40% Approximate minimum soil pH: 7.4 Nearest meteorological station to the site: NE14 which is 1.6 km from the site at coordinates 100deg.45min.

West, 41deg.14min. North The meteorological station is automatic. EXPERIMENTAL DESIGN Details of the plots Width of smallest plot is 8.5 m Length of smallest plot is 45.7 m Slope: 0.1% .

Shape: Uniform Details of direction of cultivation: E-W, parallel to long-axis Width of Bare Strip around plot: 2m This information was compiled for the GCTE-SOMNET Database, Pete Smith, Pete Falloon, David Powlson, and Jo Smith. Soil Science Department, IACR-Rothamsted, UK.