• Authors:
    • Andrasko, K.
    • Bosquet, B.
  • Year: 2010
  • Authors:
    • Scholefield, D.
    • Dhanoa, M. S.
    • Lane, S.
    • Kingston, H.
    • Donovan, N.
    • Cuttle, S.
    • Chambers, B.
    • Chadwick, D.
    • Butler, M.
    • Ashleee, N.
    • Thorman, R.
    • Cardenas, L. M.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 136
  • Issue: 3-4
  • Year: 2010
  • Summary: The objective of the present study was to measure emissions of N2O from fertilized grazed grassland that can be used to add valuable information to the limited existing data on N2O fluxes from grazed grassland and aid the development of new country-specific EFs for direct emissions from soils in the UK. This was done by evaluating the effect on N2O emissions of inorganic fertiliser N applied to grazed grassland soils over the range of N inputs 0-350 kg ha(-1). Nitrous oxide fluxes were measured using closed static chambers at 3 sites in England and Wales over a two-year period. Cumulative fluxes were calculated and the total emission regressed against applied inorganic fertiliser N in order to estimate the emission factor for N2O emissions from soils. The data showed that, the emission factor for N2O from inorganic fertiliser applied to grazed grassland soils in the UK differs from the IPCC default value of 1.25%. A nonlinear response of N2O emissions to fertiliser N application rates was observed. Annual emissions of N2O were estimated from a modelled function fitted to the measured data and after subtraction of the background flux resulted in emissions of 0.5 and 3.9 kg N2O-N ha(-1) yr(-1) for an application of 100 kg N for three locations in the UK, one in the East and the other two in the West of the UK (after combining the data from two sites), respectively. (C) 2009 Elsevier B.V. All rights reserved.
  • Authors:
    • Schulze, E. D.
    • Houwelling, S.
    • Rivier, L.
    • Friedrich, R.
    • Scholz, Y.
    • Pregger, T.
    • Levin, I.
    • Piao, S. L.
    • Peylin, P.
    • Marland, G.
    • Paris, J. D.
    • Ciais, P.
  • Source: Global Change Biology
  • Volume: 16
  • Issue: 5
  • Year: 2010
  • Summary: We analyzed the magnitude, the trends and the uncertainties of fossil-fuel CO2 emissions in the European Union 25 member states (hereafter EU-25), based on emission inventories from energy-use statistics. The stability of emissions during the past decade at EU-25 scale masks decreasing trends in some regions, offset by increasing trends elsewhere. In the recent 4 years, the new Eastern EU-25 member states have experienced an increase in emissions, reversing after a decade-long decreasing trend. Mediterranean and Nordic countries have also experienced a strong acceleration in emissions. In Germany, France and United Kingdom, the stability of emissions is due to the decrease in the industry sector, offset by an increase in the transportation sector. When four different inventories models are compared, we show that the between-models uncertainty is as large as 19% of the mean for EU-25, and even bigger for individual countries. Accurate accounting for fossil CO2 emissions depends on a clear understanding of system boundaries, i.e. emitting activities included in the accounting. We found that the largest source of errors between inventories is the use of distinct systems boundaries (e.g. counting or not bunker fuels, cement manufacturing, non-energy products). Once these inconsistencies are corrected, the between-models uncertainty can be reduced down to 7% at EU-25 scale. The uncertainty of emissions at smaller spatial scales than the country scale was analyzed by comparing two emission maps based upon distinct economic and demographic activities. A number of spatial and temporal biases have been found among the two maps, indicating a significant increase in uncertainties when increasing the resolution at scales finer than ~200 km. At 100 km resolution, for example, the uncertainty of regional emissions is estimated to be 60 g C m-2 yr-1, up to 50% of the mean. The uncertainty on regional fossil-fuel CO2 fluxes to the atmosphere could be reduced by making accurate 14C measurements in atmospheric CO2, and by combining them with transport models.
  • Authors:
    • McCarl, B. A.
    • Adams, D. M.
    • Latta, G.
    • Alig, R.
  • Source: Forest Policy and Economics
  • Volume: 12
  • Issue: 1
  • Year: 2010
  • Summary: The forest sector can contribute to atmospheric greenhouse gas reduction, while also providing other environmental, economic, and social benefits. Policy tools for climate change mitigation include carbon-related payment programs as well as laws and programs to impede the loss of agricultural and forest lands to development. Policy makers will base their expectations of the effectiveness of these strategies to some degree on anticipated land use impacts. We examine a number of scenarios about carbon prices, urban development rates, and potential future land transfers between forestry and agriculture to provide information about the potential effectiveness of policies to address climate change in the U.S. Because large areas of land can move between forestry and agricultural uses, we used the Forest and Agriculture Sector Optimization Model-Greenhouse Gases model to examine responses between sectors as part of GHG policy analysis. The model projects changes in land uses,has full carbon accounting for both forestry and agriculture, and can examine a broad range of adaptation and climate change mitigation options. Modeling results suggest that receipt of carbon-related payments by landowners in forestry and agriculture can have substantial impacts on future land use patterns, levels of terrestrial carbon sequestration, forest resource conditions, agricultural production trends, and bioenergy production.
  • Authors:
    • Karp, A.
    • Riche, A.
    • Bohan, D. A.
    • Mallott, M. D.
    • Haughton, A. J.
    • Cunningham, M.
    • Sage, R.
  • Source: Ibis
  • Volume: 152
  • Issue: 3
  • Year: 2010
  • Summary: We compared birds in a group of established and well-managed miscanthus (Miscanthus x giganteus) fields in Somerset and East Devon, southwestern England, with plots of short rotation coppice (SRC) willow, arable crops and grassland in two winters and one summer. Following early spring cutting, 19 miscanthus fields grew taller, initially produced greater cover and were less weedy than SRC. As stubble in May, the miscanthus contained broadly similar species at similar densities to arable and grassland comparison plots. By July, at 2-m-tall, miscanthus held higher densities of birds but of fewer species, most of them characteristic of woodland and scrub. SRC, previously identified as being a beneficial crop for many birds, always contained more species and individuals than miscanthus. Throughout each of two winters, 15 miscanthus plots remained unharvested and contained more wood/scrub species such as Blackbirds Turdus merula, tits, Reed Buntings Emberiza schoeniclus and Woodcock Scolopax rusticola than the comparison plots, which held more corvids and Skylarks Alauda arvensis amongst others. Similar overall mean densities of birds in the miscanthus and the comparison plots masked relatively low density variance in miscanthus and very high variance in the comparison plots. Unharvested miscanthus crops grown in place of habitat types supporting flocks of wintering birds would displace these flocks. Miscanthus plantations with open patches attracted more finches and waders in winter. The two previous studies of birds in miscanthus in the UK found more species and more individuals than we did in summer and winter. Both these studies documented high levels of weediness and patchy crop growth. In the context of this previous work our data suggest that bird use of miscanthus in summer and winter is likely to be variable, affected by region, weediness, crop structure and patchiness. While large-scale cropping of SRC in England is likely to have a positive overall impact on a suite of common farmland and woodland birds, our data suggest that miscanthus in the southwest of England may have an approximately neutral effect. However, some open farmland specialist species may be lost when planting either crop.
  • Authors:
    • Tzilivakis, J.
    • Osborne, N.
    • Hipps, N.
    • Davies, M.
    • Warner, D. J.
    • Lewis, K. A.
  • Source: The Journal of Agricultural Science
  • Volume: 148
  • Issue: 6
  • Year: 2010
  • Summary: Reducing greenhouse gas emissions and optimizing energy consumption are important for mitigating climate change and improving resource use efficiency. Strawberry (Fragaria xananassa Duch) crops are a key component of the UK soft fruit sector and potentially resource-intensive crops. This is the first study to undertake a detailed environmental impact assessment of all methods of UK strawberry production. A total of 14 systems with six additional sub-systems grown for between 1 and 3 years were identified. They were defined by the growing of short-day (Junebearer) or everbearer varieties, organic production, covering with polytunnels or grown in the open, soil-grown (with or without fumigation) or container-grown (with peat or coir substrate) and summer or spring planted. Preharvest, the global warming potential varied between 1.5 and 10.3 t CO(2) equiv/ha/crop or 0.13 and 1.14 t CO(2) equiv/t of class 1 fruit. Key factors included the use of tunnels, mulch and irrigation, sterilization of soil with fumigants and the use of peat substrate. Seasonal crops without covers grown where rotation of sufficient length reduced Verticillium (system 4) were the most efficient. System 4a (that did not use mulch) emitted 0.13 t CO(2) equiv/t of class 1 fruit. A second or third cropping year in soil-grown systems prolonged the effect of mulch and soil fumigants. Greenhouse gases from system 4 (with mulch) averaged 0.30 t CO(2) equiv/t of class 1 fruit after 3 years of cropping compared to 0.63 and 0.36 t CO(2) equiv/t after 1 and 2 years, respectively.
  • Authors:
    • Evans, K.
    • Deliopoulos, T.
    • Haydock, P. P. J.
    • Minnis, S. T.
  • Source: Crop Protection
  • Volume: 29
  • Issue: 10
  • Year: 2010
  • Summary: The soil fumigant 1,3-dichloropropene (1,3-D) has been used in the UK for the control of potato cyst nematodes (PCN), Globodera pallida (Stone) and Globodera rostochiensis (Wollenweber), but its potential herbicidal activity has not been extensively investigated in this country. Field and glasshouse studies were therefore conducted to evaluate the potential of 1,3-D for the control of weeds in potatoes, and observations were made on the severity of potato stem canker, caused by the fungus Rhizoctonia solani Kuhn [teleomorph: Thanatephorus cucumeris (Frank) Donk]. Autumn application of 1,3-D at 211.5 L active substance (as.) ha(-1) significantly suppressed the number of germinating weeds and the percentage of weed ground cover by 83% and 79%, respectively, relative to controls. There were also species-specific significant decreases (field pansy, Viola arvensis, in particular) in the number of weed seeds germinating in field soil in the glasshouse post-1,3-D treatment. The effect of 1,3-D declined in time and single (autumn or spring) or combined application produced a slight, but not significant, reduction in the number of weeds germinated on potato ridges relative to those recorded in untreated soil. The severity of stem canker on potato plants was not significantly reduced by 1,3-D but both mean number and weight of stems per plant were significantly increased compared with plants from untreated plots. These studies demonstrated that 1,3-D, in addition to giving PCN control, has efficacy against weeds; implications are the potential for reduced herbicide input in the crop rotation with accompanying economic and environmental benefits. (C) 2010 Elsevier Ltd. All rights reserved.
  • Authors:
    • Kindred, D. R.
    • Wiltshire, J. J. J.
    • Sylvester-Bradley, R.
    • Hatley, D. L. J.
    • Clarke, S.
  • Source: HGCA Project Report
  • Volume: i + 47 pp.
  • Issue: 460
  • Year: 2009
  • Summary: This report describes a second year of research that tested whether soil nitrogen supplies to cereal crops can be detected using canopy sensors; the first season was reported in HGCA Project Report No. 427. Nitrogen fertiliser experiments on cereals were established at four sites in 2006-7. In the following year, commercial cereal crops (wheat, oats or barley) were grown and, at each site, plot positions as used in the previous year were marked out for testing with a reflectance sensor. Reflectance was measured four times during tillering, between December and May (dependant on site), using a Crop Circle instrument (provided by Soilessentials Ltd) which measured reflectance at 880 nm (near-infrared, NIR) and 590 nm (orange). A Normalised Difference Vegetation Index (NDVI) was calculated to give a measure of vegetation cover. Soil mineral N (SMN) data were obtained for the sites. No fertiliser N was applied in 2008 and total N uptake at harvest was taken to represent the 'soil N supply' (SNS). Data were interpreted for relationships between canopy reflectance and soil N. The best level of tillering and ground cover was achieved at High Mowthorpe, which was sown early. Boxworth and Terrington crops were smaller, and the crop at Rosemaund was very small. High levels of N applied in 2007 had large effects on SMN at Boxworth and Terrington, but maximum amounts were smaller at High Mowthorpe or Rosemaund and maximum SMN and SNS levels were small. Use of the sensor successfully detected the differences in SMN residues at Boxworth and Terrington, especially below 120-140 kg/ha, as was found in the previous year's experiments. The relationships improved with later assessment of NDVI. Change in NDVI between assessment dates showed that canopies always grew during the 2007/08 winter but change in NDVI was less useful for predicting SNS than absolute values of NDVI. Merged data from both seasons of the study showed that NDVI signals overwinter could be interpreted according to their differences from the theoretical NDVI of an unlimited crop. It was concluded that young canopies can signal soil N status where SMN is less than 120-140 kg/ha. Effects were more certain as crops grew, so canopy sensing for soil N supplies should prove more useful as the season progresses.
  • Authors:
    • Smith, K. A.
    • Edwards, A. C.
    • Reay, D. S.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 133
  • Issue: 3-4
  • Year: 2009
  • Summary: Direct and indirect nitrous oxide (N2O) emissions and leaching losses from an intensively managed grazed pasture in the Ythan catchment, Aberdeenshire, UK, were measured and compared over a 17-month period. Simultaneous measurements of farm-wide leaching losses of N2O were also made and catchment-wide fluxes were estimated from existing N leaching data. The relative importance of direct and indirect N2O fluxes at the field, farm and catchment scale was then assessed. At the field scale we found that direct N2O emissions were low (1.2 kg N ha-1 year-1, 0.6% of N input) with indirect N2O emissions via drainage waters comprising a significant proportion (25%) of total N2O emissions. At the whole-farmscale, the N2O-N emission factor (0.003) for leached NO3-N (EF5-g) was in line with the IPCC's recent downward revision. At the catchment scale, a direct N2O flux of 1.9 kg N ha-1 year-1 and an indirect flux of 0.06 kg N2O-N ha-1 year-1 were estimated. This study lends further support to the recent downward revision of the IPCC emission factor for N2O arising from leached N in surface and ground waters (EF5-g) and highlights the need for multiple point sampling to ensure that the importance of indirect N2O losses via drainage waters is not misrepresented at the farm and catchment scales.
  • Authors:
    • Bol, R.
    • Krull, E.
    • Lopez-Capel, E.
    • Sohi, S.
  • Source: CSIRO Land and Water Science Report
  • Year: 2009