@article{KernHellebrandGoemmeletal.2012,
  author    = {Kern, J{\"u}rgen and Hellebrand, Hans J{\"u}rgen and G{\"o}mmel, Michael and Ammon, Christian and Berg, Werner},
  title     = {Effects of climatic factors and soil management on the methane flux in soils from annual and perennial energy crops},
  series = {Biology and fertility of soils},
  volume    = {48},
  journal   = {Biology and fertility of soils},
  number    = {1},
  publisher = {Springer},
  address   = {New York},
  issn      = {0178-2762},
  doi       = {10.1007/s00374-011-0603-z},
  pages     = {1 -- 8},
  year      = {2012},
  abstract  = {Methane flux rates were measured on a loamy sand soil within perennial and annual energy crops in northeast Germany. The study was performed in closed chambers between 2003 and 2005 with four measurements per week. A mixed linear model including the fixed effects of year, rotation period, crop and fertilisation was applied to determine the influence of climatic factors and soil management on the CH4 flux. Soil water content and air temperature were added as co-variables. With the exception of air temperature, all fixed effects and the co-variable soil water content influenced the CH4 flux. The soil of annual crops consumed 6.1 mu g CH4 m(-2) h(-1), significantly more than the soil of perennial crops with 4.3 mu g CH4 m(-2) h(-1). It is suggested that soil water content plays the key role in CH4 flux between pedosphere and atmosphere. In the range of water contents between 5\% and 15\%, our model describes that a soil water content increase of 1\% induces a net emission of 0.375 mu g CH4 m(-2) h(-1). As the soil of the experimental field was well-drained and aerobic, it represented a net sink for CH4 throughout the study period.},
  language  = {en}
}
@article{WernerWernerWielandetal.2014,
  author    = {Werner, Andrea and Werner, Andreas and Wieland, Ralf and Kersebaum, Kurt-Christian and Mirschel, Wilfried and Ende, Hans-Peter and Wiggering, Hubert},
  title     = {Ex ante assessment of crop rotations focusing on energy crops using a multi-attribute decision-making method},
  series = {Ecological indicators : integrating monitoring, assessment and management},
  volume    = {45},
  journal   = {Ecological indicators : integrating monitoring, assessment and management},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1470-160X},
  doi       = {10.1016/j.ecolind.2014.03.013},
  pages     = {110 -- 122},
  year      = {2014},
  abstract  = {The cultivation of plants for use as energy resources is an agricultural and industrial sector with potentially synergistic benefits related to protecting the environment and generating income. Against the background of increasing land-use changes and new agricultural approaches to the production of energy crops, we present a method for identifying future-oriented crop rotations that supports both the economic and environmental components of decision-making strategies with respect to agriculture-related policy decisions (regional mission statements). The conflicting aspects of these objectives can be addressed with the analytic hierarchy process (AHP), a multi-attribute decision-making method that was integrated here. Three models are used to generate simulations of the defined objectives over a planning period of 30 years under the current climate scenario and provide input data for the multi-attribute assessment of several crop rotations. Based on the entire evaluation process, dimensionless global priority vectors are used to indicate how well the crop rotations meet the requirements of the defined mission statement. The method is tested in a municipality in NE Germany. (C) 2014 Elsevier Ltd. All rights reserved.},
  language  = {en}
}