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Author Klosterhalfen, A.; Herbst, M.; Weihermueller, L.; Graf, A.; Schmidt, M.; Stadler, A.; Schneider, K.; Subke, J.-A.; Huisman, J.A.; Vereecken, H. doi  openurl
  Title Multi-site calibration and validation of a net ecosystem carbon exchange model for croplands Type Journal Article
  Year 2017 Publication Ecological Modelling Abbreviated Journal Ecol. Model.  
  Volume 363 Issue Pages (down) 137-156  
  Keywords AgroC; Soil respiration; Carbon balance; Winter wheat; Grassland; NEE; LOLIUM-PERENNE L; SOIL HETEROTROPHIC RESPIRATION; LAND-SURFACE MODELS; EDDY-COVARIANCE; WINTER-WHEAT; CARBOHYDRATE CONTENT; TURNOVER MODEL; ROTHC MODEL; ROOT RATIOS; CO2 EFFLUX  
  Abstract Croplands play an important role in the carbon budget of many regions. However, the estimation of their carbon balance remains difficult due to diversity and complexity of the processes involved. We report the coupling of a one-dimensional soil water, heat, and CO2 flux model (SOILCO2), a pool concept of soil carbon turnover (RothC), and a crop growth module (SUCROS) to predict the net ecosystem exchange (NEE) of carbon. The coupled model, further referred to as AgroC, was extended with routines for managed grassland as well as for root exudation and root decay. In a first step, the coupled model was applied to two winter wheat sites and one upland grassland site in Germany. The model was calibrated based on soil water content, soil temperature, biometric, and soil respiration measurements for each site, and validated in terms of hourly NEE measured with the eddy covariance technique. The overall model performance of AgroC was sufficient with a model efficiency above 0.78 and a correlation coefficient above 0.91 for NEE. In a second step, AgroC was optimized with eddy covariance NEE measurements to examine the effect of different objective functions, constraints, and data-transformations on estimated NEE. It was found that NEE showed a distinct sensitivity to the choice of objective function and the inclusion of soil respiration data in the optimization process. In particular, both positive and negative day- and nighttime fluxes were found to be sensitive to the selected optimization strategy. Additional consideration of soil respiration measurements improved the simulation of small positive fluxes remarkably. Even though the model performance of the selected optimization strategies did not diverge substantially, the resulting cumulative NEE over simulation time period differed substantially. Therefore, it is concluded that data transformations, definitions of objective functions, and data sources have to be considered cautiously when a terrestrial ecosystem model is used to determine NEE by means of eddy covariance measurements. (C) 2017 Elsevier B.V. All rights reserved.  
  Address 2017-11-09  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0304-3800 ISBN Medium  
  Area Expedition Conference  
  Notes CropM, ft_MACSUR Approved no  
  Call Number MA @ admin @ Serial 5216  
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Author Eory, V.; MacLeod, M.; Shrestha, S.; Roberts, D. url  openurl
  Title Linking an economic and a life-cycle analysis biophysical model to support agricultural greenhouse gas mitigation policy Type Journal Article
  Year 2014 Publication German Journal of Agricultural Economics Abbreviated Journal German Journal of Agricultural Economics  
  Volume 63 Issue Pages (down) 133-142  
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  Abstract Greenhouse gas (GHG) mitigation is one of the main challenges facing agriculture, exacerbated by the increasing demand for food, in particular for livestock products. Production expansion needs to be accompanied by reductions in the GHG emission intensity of agricultural products, if significant increases in emissions are to be avoided. Suggested farm management changes often have systemic effects on farm, therefore their investigation requires a whole farm approach. At the same time, changes in GHG emissions arising offfarm in food supply chains (pre- or post-farm) can also occur as a consequence of these management changes. A modelling framework that quantifies the whole-farm, life-cycle effects of GHG mitigation measures on emissions and farm finances has been developed. It is demonstrated via a case study of sexed semen on Scottish dairy farms. The results show that using sexed semen on dairy farms might be a costeffective way to reduce emissions from cattle production by increasing the amount of lower emission intensity ‘dairy beef’ produced. It is concluded that a modelling framework combining a GHG life cycle analysis model and an economic model is a useful tool to help designing targeted agri-environmental policies at regional and national levels. It has the flexibility to model a wide variety of farm types, locations and management changes, and the LCA-approach adopted helps to ensure that GHG emission leakage does not occur in the supply chain.  
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  Notes TradeM Approved no  
  Call Number MA @ admin @ Serial 4670  
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Author Brylińska, M.; Sobkowiak, S.; Stefańczyk, E.; Śliwka, J. url  doi
openurl 
  Title Potato cultivation system affects population structure of Phytophthora infestans Type Journal Article
  Year 2016 Publication Fungal Ecology Abbreviated Journal Fungal Ecology  
  Volume 20 Issue Pages (down) 132-143  
  Keywords SSR; Population genetic structure; Late blight; Potato; late blight resistance; mating-type; microsatellite markers; phenotypic diversity; sexual reproduction; genotypic diversity; nordic countries; severe outbreaks; sarpo mira; pathogenicity  
  Abstract Phytophthora infestans is one of the most destructive potato pathogens. Many factors influence the population structure of P. infestans, including migration, climate and type of potato cultivation. Here, we analyse 365 P. infestans isolates collected from three regions of Poland over three years. We determined mating type, mitochondrial haplotype, resistance to metalaxyl, virulence and polymorphism at 14 simple sequence repeat (SSR) loci. Analysis of SSR markers showed high genetic diversity associated with this population. Model-based structure analysis grouped 299 unique genotypes into four main clusters. The P. infestans isolates collected from the Mlochow region, which has the most intensive level of potato cultivation, formed a distinct cluster, indicating a strong effect of the cultivation system on pathogen population structure. Three clusters contained isolates with frequent presence of three alleles at one locus, which may affect their capacity for sexual reproduction and preserve groups of fit genotypes that propagate asexually. (C) 2016 Elsevier Ltd and The British Mycological Society.  
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  ISSN 1754-5048 ISBN Medium Article  
  Area Expedition Conference  
  Notes CropM, ft_macsur Approved no  
  Call Number MA @ admin @ Serial 4720  
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Author Twardy, S.; Kopacz, M. openurl 
  Title Comparison of concentrations and loads of macronutrients brought with precipitation and leaching from the soil profile Type Journal Article
  Year 2014 Publication Polish Journal of Environmental Studies Abbreviated Journal Pol. J. Environ. Stud.  
  Volume 23 Issue 3a Pages (down) 132-136  
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  Notes CropM Approved no  
  Call Number MA @ admin @ Serial 4640  
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Author Mitter, H.; Sinabell, F.; Schmid, E. openurl 
  Title Impacts of climate and policy change on Austrian protein crop supply balances Type Conference Article
  Year 2015 Publication Jahrbuch der ÖGA Abbreviated Journal  
  Volume 23 Issue Pages (down) 131-140  
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  Area Expedition Conference 23. ÖGA Jahrestagung gemeinsam mit der 41. SGA-Jahrestagung “Grenzen der Qualitätsstrategie im Agrarsektor”, 2013-09-12 to 2013-09-14, Zürich  
  Notes TradeM Approved no  
  Call Number MA @ admin @ Serial 5030  
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