|
|
Tantari, A. (2015). The role of CAP direct payment in the support and stabilisation of farm income: empirical evidences from a constant sample of Italian farms (Vol. 5).
Abstract: The main objective of CAP Direct payments (DP) has been to increase and stabilise farm income together with a large number of additional goals (Gardner, 1991). Despite its importance, there are limited empirical evidences on farm income variability over time at farm level apart Vrolijk and Poppe (2008) and Vrolijk, de Bont, van der Veen, and Poppe (2009). The analysis focuses of the following research questions:• What is the amount of the support provided by DP? How the income of Italian farms will be affected by reductions of DP levels?• What is the extent of farm income variability over time? Is it the same in all types of farms?• Where is this variability coming from?• Do CAP direct payments reduce farm income variability? How do DP affect it? Are DP targeted to stabilise the income of those farms facing larger income variability? The analysis has been developed on the individual farms belonging to the whole Italian sample of the EU FADN farms during all years of the decade 2003-2012. The variability of farm income (FI) is assessed by calculating variance and Coefficient of Variation (CV) over the 10 year period for each farm for each relevant income component. The role of DP on income stabilisation is assessed by means of variance decomposition by income sources (Burt and Finley, 1968; El Benni and Finger, 2013; Mishra and El-Osta, 2001).The presence of DP allows for a reduction of the variability of farm income: the variability of FI when DP are not accounted for is higher than that of the whole FI. Finally, DP seem to be not targeted to those farms facing the highest level of market income variability. These results support the hypothesis that there is a potentially large room for better design the DP policy to reduce income variability. No Label
|
|
|
|
Tao, F., Rötter, R. P., Palosuo, T., Höhn, J., Peltonen-Sainio, P., Rajala, A., et al. (2015). Assessing climate effects on wheat yield and water use in Finland using a super-ensemble-based probabilistic approach. Clim. Res., 65, 23–37.
Abstract: We adapted a large area crop model, MCWLA-Wheat, to winter wheat Triticum aestivum L. and spring wheat in Finland. We then applied Bayesian probability inversion and a Markov Chain Monte Carlo technique to analyze uncertainties in parameter estimations and to optimize parameters. Finally, a super-ensemble-based probabilistic projection system was updated and applied to project the effects of climate change on wheat productivity and water use in Finland. The system used 6 climate scenarios and 20 sets of crop model parameters. We projected spatiotemporal changes of wheat productivity and water use due to climate change/variability during 2021-2040, 2041-2070, and 2071-2100. The results indicate that with a high probability wheat yields will increase substantially in Finland under the tested climate change scenarios, and spring wheat can benefit more from climate change than winter wheat. Nevertheless, in some areas of southern Finland, wheat production will face increasing risk of high temperature and drought, which can offset the benefits of climate change on wheat yield, resulting in an increase in yield variability and about 30% probability of yield decrease for spring wheat. Compared with spring wheat, the development, photosynthesis, and consequently yield will be much less enhanced for winter wheat, which, together with the risk of extreme weather, will result in an up to 56% probability of yield decrease in eastern parts of Finland. Our study explicitly para meterized the effects of extreme temperature and drought stress on wheat yields, and accounted for a wide range of wheat cultivars with contrasting phenological characteristics and thermal requirements.
|
|
|
|
Tao, F., Zhang, S., Zhang, Z., & Rötter, R. P. (2015). Temporal and spatial changes of maize yield potentials and yield gaps in the past three decades in China. Agric. Ecosyst. Environ., 208, 12–20.
Abstract: The precise spatially explicit knowledge about crop yield potentials and yield gaps is essential to guide sustainable intensification of agriculture. In this study, the maize yield potentials from 1980 to 2008 across the major maize production regions of China were firstly estimated by county using ensemble simulation of a well-validated large scale crop model, i.e., MCWLA-Maize model. Then, the temporal and spatial patterns of maize yield potentials and yield gaps during 1980-2008 were presented and analyzed. The results showed that maize yields became stagnated at 32.4% of maize-growing areas during the period. In the major maize production regions, i.e., northeastern China, the North China Plain (NCP) and southwestern China, yield gap percentages were generally less than 40% and particularly less than 20% in some areas. By contrast, in northern and southern China, where actual yields were relatively lower, yield gap percentages were generally larger than 40%. The areas with yield gap percentages less than 20% and less than 40% accounted for 8.2% and 27.6% of maize-growing areas, respectively. During the period, yield potentials decreased in the NCP and southwestern China due to increase in temperature and decrease in solar radiation; by contrast, increased in northern, northeastern and southeastern China due to increases in both temperature and solar radiation. Yield gap percentages decreased generally by 2% per year across the major maize production regions, although increased in some areas in northern and northeastern China. The shrinking of yield gap was due to increases in actual yields and decreases in yield potentials in the NCP and southwestern China; and due to larger increases in actual yields than in yield potentials in northeastern and southeastern China. The results highlight the importance of sustainable intensification of agriculture to close yield gaps, as well as breeding new cultivars to increase yield potentials, to meet the increasing food demand. (C) 2015 Elsevier B.V. All rights reserved.
|
|
|
|
Tao, F., Zhang, Z., Zhang, S., & Rötter, R. P. (2015). Heat stress impacts on wheat growth and yield were reduced in the Huang-Huai-Hai Plain of China in the past three decades. European Journal of Agronomy, 71, 44–52.
Abstract: Heat stress impacts on crop growth and yield have been investigated by controlled-environment experiments, however little is known about the impacts under field conditions at large spatial and temporal scales, particularly in a setting with farmers’ autonomous adaptations. Here, using detailed experiment Observations at 34 national agricultural meteorological stations spanning from 1981 to 2009 in the Huang-Huai-Hai Plain (HHHP) of China, we investigated the changes in climate and heat stress during wheat reproductive growing period (from heading to maturity) and the impacts of climate change and heat stress on reproductive growing duration (RGD) and yield in a setting with farmers’ autonomous adaptations. We found that RGD and growing degree days above 0 degrees C (GDD) from heading to maturity increased, which increased yield by similar to 14.85%, although heat stress had negative impacts on RGD and yield. During 1981-2009, high temperature (>34 degrees C) degree days (HDD) increased in the northern part, however decreased in the middle and southern parts of HHHP due to advances in heading and maturity dates. Change in HDD, together with increase in GDD and decrease in solar radiation (SRD), jointly increased wheat yield in the northern and middle parts but reduced it in the southern part of HHHP. During the study period, increase in GDD and decrease in SRD had larger impacts on yield than change in HDD. However, with climate warming of 2 degrees C, damage of heat stress on yield may offset a large portion of the benefits from increases in RGD and GDD, and eventually result in net negative impacts on yield in the northern part of HHHP. Our study showed that shifts in cultivars and wheat production system dynamics in the past three decades reduced heat stress impacts in the HHHP. The insights into crop response and adaptation to climate change and climate extremes provide excellent evidences and basis for improving climate change impact study and designing adaptation measures for the future. (C) 2015 Elsevier B.V. All rights reserved.
|
|
|
|
Topp, C. (2015). Pesticide management in Scottish spring barley – insights from sowing dates (Vol. 5).
Abstract: Better management of pesticides is a potentially important strategy for reducing environmental impact while maintaining yields. Pesticide use is influenced by several drivers, including sowing date, which can directly impact disease burden. Analysis of sowing dates for spring barley was the first stage of this project, which aims to provide insight into areas of farm management which can be optimised to reduce environmental impact. Sowing dates were taken from the Adopt a Crop database, which contains data from 1983 onwards for commercial farms across Scotland. Work was carried out at three levels: national, to provide an overall picture of historical patterns; regional, to highlight differences within Scotland; and case study, to determine whether the national trend was visible in a single region. A general trend towards later sowing of spring barley in Scotland is visible – yet, this pattern is less pronounced in certain regions. Future work must therefore consider what factors have lead to this shift, to more fully understand interactions between sowing date and the environment. No Label
|
|
