The carbon footprints of food crop production

The agriculture sector contributes significantly to global carbon emissions from diverse sources such as product and machinery manufacture, transport of materials and direct and indirect soil greenhouse gas emissions. In this article, we use farm survey data from the east of Scotland combined with published estimates of emissions for individual farm operations to quantify the relative contribution of a range of farming operations and determine the carbon footprint of different crops (e.g. legumes, winter and spring cereals, oilseed rape, potato) and farming practices (conventional, integrated and organic). Over all crops and farm types, 75% of the total emissions result from nitrogen fertilizer use (both organic and inorganic)—from production, application, and direct nitrous oxide emissions from the soil resulting from application. Once nitrogen is accounted for, there are no major differences between organic, integrated or conventional farming practices. These data highlight opportunities for carbon mitigation and will be of value for inclusion in full life cycle analyses of arable production systems and in calculations of greenhouse gas balance associated with land-use change.

[1]  Pete Smith,et al.  Estimating the pre-harvest greenhouse gas costs of energy crop production , 2008 .

[2]  S. Ogle,et al.  Agricultural management impacts on soil organic carbon storage under moist and dry climatic conditions of temperate and tropical regions , 2005 .

[3]  Robert M. Boddey,et al.  The success of BNF in soybean in Brazil , 2003, Plant and Soil.

[4]  Cathy Hawes,et al.  Functional approaches for assessing plant and invertebrate abundance patterns in arable systems , 2009 .

[5]  W. Parton,et al.  Life-cycle assessment of net greenhouse-gas flux for bioenergy cropping systems. , 2007, Ecological applications : a publication of the Ecological Society of America.

[6]  B. Ney,et al.  The challenge of improving nitrogen use efficiency in crop plants: towards a more central role for genetic variability and quantitative genetics within integrated approaches. , 2007, Journal of experimental botany.

[7]  David S. Powlson,et al.  Meeting Europe's climate change commitments: quantitative estimates of the potential for carbon mitigation by agriculture , 2000 .

[8]  T. Alvarez,et al.  Epigeic Collembola in winter wheat under organic, integrated and conventional farm management regimes , 2001 .

[9]  S. Polasky,et al.  Agricultural sustainability and intensive production practices , 2002, Nature.

[10]  B. Grant,et al.  Canadian greenhouse gas mitigation options in agriculture , 2001, Nutrient Cycling in Agroecosystems.

[11]  Tim Lang,et al.  Farm costs and food miles: an assessment of the full cost of the UK weekly food basket , 2005 .

[12]  Geoffrey R. Squire,et al.  Community-scale seedbank response to less intense rotation and reduced herbicide input at three sites , 2000 .

[13]  R. Lark,et al.  Carbon losses from all soils across England and Wales 1978–2003 , 2005, Nature.

[14]  Jo Smith,et al.  Greenhouse gas mitigation in agriculture , 2008, Philosophical Transactions of the Royal Society B: Biological Sciences.

[15]  C. Topp,et al.  Estimating resource use efficiencies in organic agriculture: a review of budgeting approaches used , 2007 .

[16]  Pete Smith,et al.  Energy crops: current status and future prospects , 2006 .

[17]  N. Batjes,et al.  Modeling global annual N2O and NO emissions from fertilized fields , 2002 .

[18]  G. Armstrong.  Carabid beetle diversity and abundance in organic potatoes and conventionally grown seed potatoes in the north of Scotland. , 1995 .

[19]  R. Desjardins,et al.  The fate of nitrogen in agroecosystems: An illustration using Canadian estimates , 2003, Nutrient Cycling in Agroecosystems.

[20]  S. Polasky,et al.  Land Clearing and the Biofuel Carbon Debt , 2008, Science.

[21]  Corinne Le Quéré,et al.  Climate Change 2013: The Physical Science Basis , 2013 .

[22]  David S. Powlson,et al.  Preliminary estimates of the potential for carbon mitigation in European soils through no‐till farming , 1998 .

[23]  R. B. Root.  Organization of a Plant-Arthropod Association in Simple and Diverse Habitats: The Fauna of Collards (Brassica Oleracea) , 1973 .

[24]  Andrew P. Whitmore,et al.  Is it possible to increase the sustainability of arable and ruminant agriculture by reducing inputs , 2009 .

[25]  R. Lal,et al.  Carbon emission from farm operations. , 2004, Environment international.

[26]  W. Sutherland,et al.  Post‐war changes in arable farming and biodiversity in Great Britain , 2002 .

[27]  Hiroshi Nakano,et al.  Fuel consumption-derived CO2 emissions under conventional and reduced tillage cropping systems in northern Japan , 2003 .

[28]  R. Milne,et al.  Annual Report for submission under the Framework Convention on Climate Change , 2001 .

[29]  R. Lal.  Agricultural activities and the global carbon cycle , 2004, Nutrient Cycling in Agroecosystems.

[30]  L. Drinkwater,et al.  Fundamental Differences Between Conventional and Organic Tomato Agroecosystems in California , 1995 .

[31]  L. Firbank,et al.  Identifying and managing the conflicts between agriculture and biodiversity conservation in Europe - a review , 2008 .

[32]  L. K. Ward,et al.  The role of weeds in supporting biological diversity within crop fields , 2003 .

[33]  T. Daniels.  Scholarlycommons Departmental Papers (city and Regional Planning) Department of City and Regional Planning Integrating Forest Carbon Sequestration into a Cap-and-trade Program to Reduce Net Carbon Emissions Integrating Forest Carbon Sequestration into a Cap-and-trade Program to Reduce Net Carbon Emi , 2022 .

[34]  A. Bouwman,et al.  Biomass, composition and temporal dynamics of soil organisms of a silt loam soil under conventional and integrated management. , 1990 .

[35]  B. A. Stout,et al.  Energy Use and Management in Agriculture , 1984 .

[36]  B. Kromp.  Carabid beetles (Coleoptera, Carabidae) as bioindicators in biological and conventional farming in Austrian potato fields , 1990, Biology and Fertility of Soils.

[37]  R. Betts,et al.  Changes in Atmospheric Constituents and in Radiative Forcing. Chapter 2 , 2007 .

[38]  Jacinto F. Fabiosa,et al.  Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land-Use Change , 2008, Science.

[39]  N. Aebischer,et al.  A comparison of the flora and arthropod fauna of organically and conventionally grown winter wheat in southern England , 1994 .