Barnes, A., Shrestha, S., Thomson, S., Toma, L., Mathews, K., & Sutherland, L. A. (2014). Comparing visions for CAP reforms post 2015: Farmer intentions and farm bio-economic modelling. FACCE MACSUR Mid-term Scientific Conference, 3(S) Sassari, Italy.
Abstract: This paper illustrates the impacts of two of the potential CAP reform post 2015 scenarios using an optimising farm level model and compares results with farmers’ perception about the policy changes, captured in a farmer intentions survey. The model results suggest that beef farms suffer a loss in farm net margins under fully decoupled (up to -21%) as well as under partially decoupled scenario (up to -19%) compared to current historical single farm payments. The model also shows that farm respond by reducing the number of beef animals on farm by up to 5%. However, under a partial decoupled scenario, beef farms increase calf numbers by 15% to benefit from coupled calf payment. A survey of 1,400 beef producers with respect to their intentions toward 2020 was conducted in the Summer of 2013. A set of hypothetical payment scenarios was used to test self-reported response to a number of scenarios related to expanding and extensifying. These were compared with the modelling results and found a range of responses which could, we argue, be used for future calibration and ‘sense-checking’ of results within future modelling strategies.
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Grosz, B., & Dechow, R. (2014). Comparison of measured and modelled soil organic carbon for a northern European long-term experiment site. FACCE MACSUR Mid-term Scientific Conference, 3(S) Sassari, Italy.
Abstract: Soil organic carbon is a key variable with regard to soil fertility influencing yield and yield security of agricultural crop production by regulating water budget and nutrient cycling. Those services might become even more relevant with respect to climate change. The sensitivity of crop yields on soil organic carbon content is influenced by site-specific conditions. To assess future vulnerability of yield security with respect to soil organic carbon contents in European croplands soil-crop models must consider the interaction of SOC and crop growth. Long term experiments that include treatments which lead to variable soil organic carbon contents can provide information on those relationships. Because the effect of soil fertility functions supported by SOC depends on a range of natural and anthropogenic factors we used various long term experiments in Sweden and Germany to evaluate the model CENTURY4.6. Thereafter we examined the impact of SOC on crop yields on site level by scenario runs modifying initial SOC levels and weather conditions. Preliminary results show differences in the modeled and observed soil organic carbon values for a range of observed long term experiments. The difference between modelled and measured of SOC stocks is up to 30% after 56 years. Overall, The use of the default values and setting were not appropriate to derive acceptable results, so the adjustment of some model parameter are required.
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Maggio, A. (2014). Crop responses to soil salinization in the context of climate change. FACCE MACSUR Mid-term Scientific Conference, 3(S) Sassari, Italy.
Abstract: Soil salinization is an expanding phenomenon, exacerbated by climate change. Mediterranean environments are exposed to salinization. Assessment of the specific crop-environment interactions is therefore critical for these areas. In this context, models to evaluate crop response to salinity, including applications of SWAP and Hydrus models to study viable water management options and water movement in salinized agricultural zones can contribute to identify optimal mitigation strategies.
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Rötter, R. P. (2014). Cross-cutting uncertainties in MACSUR impact projections. FACCE MACSUR Mid-term Scientific Conference, 3(S) Sassari, Italy.
Abstract: Projections into the future, such as climate change impact projections on crop production for a given region, or, on global food prices and trade are inherently uncertain. Uncertainty does not fall within a single discipline but is dealt with by a wide variety of disciplines, themes and problem domains. Model uncertainty pertaining to the impact modelling chain from climate via crop and livestock to economic and trade modelling is only part of the overall uncertainty*. There is also scenario uncertainty and many other known and unknown “unknowns”1 to be considered in efforts such as MACSUR and its themes (CropM, LiveM, TradeM) to advance model-based integrated assessment of climate change risk assessment for agriculture and food security. Propagation of uncertainties along the climate change impact modelling chain has been portrayed as “uncertainty cascade” 2. We will present different basic approaches for evaluating uncertainty in models. So far, studies addressing quantification and reporting of uncertainties in impact projections still largely focus on two major sources, i.e. the shares originating from climate modelling and from crop modelling. However, a more comprehensive treatment of uncertainty and how it is reported is urgently needed.
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Jorgenson, J. S. (2014). Data format standards and variable mapping. FACCE MACSUR Mid-term Scientific Conference, 3(S) Sassari, Italy.
Abstract: Short report on work being done tools used for standardising data formats, including variable name mapping.
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