Hoffmann, H., Zhao, G., Asseng, S., Bindi, M., Biernath, C., Constantin, J., et al. (2016). Impact of spatial soil and climate input data aggregation on regional yield simulations. PLoS One, 11(4), e0151782.
Abstract: We show the error in water-limited yields simulated by crop models which is associated with spatially aggregated soil and climate input data. Crop simulations at large scales (regional, national, continental) frequently use input data of low resolution. Therefore, climate and soil data are often generated via averaging and sampling by area majority. This may bias simulated yields at large scales, varying largely across models. Thus, we evaluated the error associated with spatially aggregated soil and climate data for 14 crop models. Yields of winter wheat and silage maize were simulated under water-limited production conditions. We calculated this error from crop yields simulated at spatial resolutions from 1 to 100 km for the state of North Rhine-Westphalia, Germany. Most models showed yields biased by <15% when aggregating only soil data. The relative mean absolute error (rMAE) of most models using aggregated soil data was in the range or larger than the inter-annual or inter-model variability in yields. This error increased further when both climate and soil data were aggregated. Distinct error patterns indicate that the rMAE may be estimated from few soil variables. Illustrating the range of these aggregation effects across models, this study is a first step towards an ex-ante assessment of aggregation errors in large-scale simulations.
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Ebrahimi, E., Manschadi, A. M., Neugschwandtner, R. W., Eitzinger, J., Thaler, S., & Kaul, H. - P. (2016). Assessing the impact of climate change on crop management in winter wheat – a case study for Eastern Austria. J. Agric. Sci., 154(07), 1153–1170.
Abstract: Climate change is expected to affect optimum agricultural management practices for autumn-sown wheat, especially those related to sowing date and nitrogen (N) fertilization. To assess the direction and quantity of these changes for an important production region in eastern Austria, the agricultural production systems simulator was parameterized, evaluated and subsequently used to predict yield production and grain protein content under current and future conditions. Besides a baseline climate (BL, 1981–2010), climate change scenarios for the period 2035–65 were derived from three Global Circulation Models (GCMs), namely CGMR, IPCM4 and MPEH5, with two emission scenarios, A1B and B1. Crop management scenarios included a combination of three sowing dates (20 September, 20 October, 20 November) with four N fertilizer application rates (60, 120, 160, 200 kg/ha). Each management scenario was run for 100 years of stochastically generated daily weather data. The model satisfactorily simulated productivity as well as water and N use of autumn- and spring-sown wheat crops grown under different N supply levels in the 2010/11 and 2011/12 experimental seasons. Simulated wheat yields under climate change scenarios varied substantially among the three GCMs. While wheat yields for the CGMR model increased slightly above the BL scenario, under IPCM4 projections they were reduced by 29 and 32% with low or high emissions, respectively. Wheat protein appears to increase with highest increments in the climate scenarios causing the largest reductions in grain yield (IPCM4 and MPEH-A1B). Under future climatic conditions, maximum wheat yields were predicted for early sowing (September 20) with 160 kg N/ha applied at earlier dates than the current practice.
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Hunter, A. N. L. Evaluation of Joint Programming to address grand societal challenges.
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Bojar, W. (2013). Factsheets of the models (Vol. 1).
Abstract: The exploration of adaptation and mitigation measures in the context of global challenges like climate change, food security and expected demographic boom is an field of research of growing importance. Over the last decades many research groups have been developing economic-trade models to analyse consequences on farm welfare, market supply and trade, some of them also address food security and other global concerns. There are many different ways to tackle these issues and the specific advantages and limitations of alternative modelling strategies are not yet well understood. The objective of the WP1 T1.1 task within TradeM theme of MACSUR is to use the results of a survey on trade and economic models of MACSUR Consortium partners to show which topics are currently addressed in the different models, which methods are used and how well these tools are prepared for an integration with other models like climate, crop and livestock models. This work was co-financed by NCBiR, Contract no. FACCE JPI/04/2012 – P100 PARTNER No Label
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Bojar, W. (2013). MACSUR TradeM Workshop Exploring new ideas for trade and agriculture model integration for assessing the impacts of climate change on food security (Vol. 1).
Abstract: The first TradeM workshop was held at Haifa University (Israel), 3-5 March 2013. It was a state-of-the-art Workshop ‘Economic Modelling on Agriculture with Climate Change for Food Security’. Sixteen papers are presented, following a call for abstracts submitted in December 2012. Presented, reviewed and discussed models, their inputs, outputs and main results of case-study analyses let indicate of how the model can be used to analyze the impacts of climate change on food security, how the model can contribute to, and benefit from other economic and/or crop and livestock models and what input is needed from CropM and LiveM. There were explored ideas for closer integration and linkage between agriculture and economic models and between economic models at different levels, addressing issues of model structure, scale and data processing. Focus was on model comparison, gap analysis, scientific advancements and improvements. We also addressed the key challenges of the economic models (macro- versus micro-economics; uncertainty versus risks; variability and distribution), and identified ways to cope with scaling, uncertainty, risks. The workshop let identify the requirements from CropM and LiveM, find policy questions that MACSUR is going to address, start with the content of the case studies and plan for publication of scientific papers. The sessions were broadcast live via the internet. Twenty-four registered participants and about 65 local visitors attended the workshop.This work was co-financed by NCBiR, Contract no. FACCE JPI/04/2012 – P100 PARTNER No Label
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