Rees R.M.,Carbon Management Center |
Baddeley J.A.,Carbon Management Center |
Bhogal A.,ADAS Boxworth |
Ball B.C.,Carbon Management Center |
And 7 more authors.
Soil Science and Plant Nutrition | Year: 2013
Nitrous oxide (N2O) makes the single largest contribution to greenhouse gas (GHG) emissions from UK and European Union agriculture. Ambitious government targets for GHG mitigation are leading to the implementation of changes in agricultural management in order to reduce these emissions (mitigation measures). We review the evidence for the contribution of those measures with the greatest mitigation potential which provide an estimated 4.3 t CO2e ha-1 y-1 GHG reduction in the UK. The mitigation options considered were: using biological fixation to provide nitrogen (N) inputs (clover, Trifolium), reducing N fertilizer, improving land drainage, avoiding N excess, fully accounting for manure/slurry N, species introduction (including legumes), improved timing of mineral fertilizer N application, nitrification inhibitors, improved timing of slurry and manure application, and adopting systems less reliant on inputs. These measures depend mostly on increasing the efficiency of N fertilizer use and improving soil conditions; however, they provide the added benefit of increasing the economic efficiency of farming systems, and can often be viewed as "win-win" solutions. © 2013 Copyright Taylor and Francis Group, LLC.
Topp C.F.E.,Crop and Soil Systems |
Wang W.,Information Technology |
Cloy J.M.,Carbon Management Center |
Rees R.M.,Carbon Management Center |
Hughes G.,Crop and Soil Systems
Entropy | Year: 2013
Boundary line models for N2O emissions from agricultural soils provide a means of estimating emissions within defined ranges. Boundary line models partition a twodimensional region of parameter space into sub-regions by means of thresholds based on relationships between N2O emissions and explanatory variables, typically using soil data available from laboratory or field studies. Such models are intermediate in complexity between the use of IPCC emission factors and complex process-based models. Model calibration involves characterizing the extent to which observed data are correctly forecast. Writing the numerical results from graphical two-threshold boundary line models as 3×3 prediction-realization tables facilitates calculation of expected mutual information, a measure of the amount of information about the observations contained in the forecasts. Whereas mutual information characterizes the performance of a forecaster averaged over all forecast categories, specific information and relative entropy both characterize aspects of the amount of information contained in particular forecasts. We calculate and interpret these information quantities for experimental N2O emissions data. © 2013 by the authors; licensee MDPI, Basel, Switzerland.
Yan M.,Nanjing Agricultural University |
Cheng K.,Nanjing Agricultural University |
Yue Q.,Nanjing Agricultural University |
Yan Y.,Nanjing Agricultural University |
And 4 more authors.
Environmental Science and Pollution Research | Year: 2016
Understanding the environmental impacts of fruit production will provide fundamental information for policy making of fruit consumption and marketing. This study aims to characterize the carbon footprints of China’s fruit production and to figure out the key greenhouse gas emissions to cut with improved orchard management. Yearly input data of materials and energy in a full life cycle from material production to fruit harvest were obtained via field visits to orchards of five typical fruit types from selected areas of China. Carbon footprint (CF) was assessed with quantifying the greenhouse gas emissions associated with the individual inputs. Farm and product CFs were respectively predicted in terms of land use and of fresh fruit yield. Additionally, product CFs scaled by fruit nutrition value (vitamin C (Vc) content) and by the economic benefit from fruit production were also evaluated. The estimated farm CF ranged from 2.9 to 12.8 t CO2-eq ha−1 across the surveyed orchards, whereas the product CF ranged from 0.07 to 0.7 kg CO2-eq kg−1 fruit. While the mean product CFs of orange and pear were significantly lower than those of apple, banana, and peach, the nutrition-scaled CF of orange (0.5 kg CO2-eq g−1 Vc on average) was significantly lower than others (3.0–5.9 kg CO2-eq g−1 Vc). The income-scaled CF of orange and pear (1.20 and 1.01 kg CO2-eq USD−1, respectively) was higher than apple, banana, and peach (0.87~0.39 kg CO2-eq USD−1). Among the inputs, synthetic nitrogen fertilizer contributed by over 50 % to the total greenhouse gas (GHG) emissions, varying among the fruit types. There were some tradeoffs in product CFs between fruit nutrition value and fruit growers’ income. Low carbon production and consumption policy and marketing mechanism should be developed to cut down carbon emissions from fruit production sector, with balancing the nutrition value, producer’s income, and climate change mitigation. © 2015, Springer-Verlag Berlin Heidelberg.