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Data extracted in October 2021
Fiche created in March 2024
Note to the reader: This general fiche summarises all the environmental and climate impacts of ORGANIC FARMING SYSTEMS found in a review of 31 synthesis papers[1]. These papers were selected from an initial number of 223 obtained through a systematic literature search strategy, according to the inclusion criteria reported in section 4. The impacts reported here are those for which there is scientific evidence available in published synthesis papers, what does not preclude the farming practice to have other impacts on the environment and climate still not covered by primary studies or by synthesis papers.
The synthesis papers review a number of primary studies ranging from 7 to 164. Therefore, the assessment of impacts relies on a large number of results from the primary studies, obtained mainly in field conditions, or sometimes in lab experiments or from model simulations.
1. DESCRIPTION OF THE FARMING PRACTICE
- Description:
- Organic production is an overall system of farm management and food production that combines best environmental and climate action practices, a high level of biodiversity, the preservation of natural resources and the application of high animal welfare standards and high production standards in line with the demand of a growing number of consumers for products produced using natural substances and processes[2]
- Key descriptors:
- Organic farming systems are production systems which avoid or largely exclude the use of synthetically compounded fertilizers, pesticides, growth regulators and livestock feed additives 3.Unlike the other farming practices, discussed in the other fiches, organic systems do not consist of a single practice, but of a combination of several “elementary” farming practices, which need to be respected together. Organic systems are defined by the REGULATION (EU) 2018/848[3]
- To the maximum extent feasible, organic systems (significantly more frequently than conventional farming according to a recent meta-analysis by Alvarez, 2021 5) rely on crop rotations, multicropping, crop residues retention, no/minimum tillage, animal manures, green manures, off-farm organic wastes and aspects of biological pest control to maintain soil productivity and tilth, to supply plant nutrients and to control insects, weeds and other pests[4]
- This review compares the impacts of organic and conventional farming systems. The following types of results are included:
- Results of field experiments designed by researchers, comparing plots under organic and conventional management.
- Results of field data or farm-scale surveys on organic and conventional systems, designed and managed by farmers.
- Results of life-cycle assessments, typically considering a cradle-to-farmgate model.
- Results were grouped into two categories:
- “Organic cropping systems” includes field-scale experiments on organically-managed crops or systems of crops, while excluding results reported specifically on livestock production.
- “Organic livestock products” reports specific results (either modelling or empirical) regarding in-farm livestock production.
- “Organic mixed farming systems”, where the experiments or observations regards the integration of crops and livestock in the same farm.
- “Organic systems” regards results obtained from different and unspecified categories of organic (cropping/farming/livestock) systems.
- In all reviewed synthesis papers, results are expressed in two different units:
- per unit of cultivated area (e.g., per ha)
- per unit of product (e.g., per kg of grain).
- Since organic systems generally result in lower yields than conventional systems, the effects per unit of product may be different to those per unit of area. Consequently, where available, both types of results are reported in this review
- NA
2. EFFECTS OF THE FARMING PRACTICE ON CLIMATE AND ENVIRONMENTAL IMPACTS
(table 1)
The table below shows the number of synthesis papers with statistical tests reporting i) a significant difference between the Intervention and the Comparator, that is to say, a significant statistical effect, which can be positive or negative; or ii) a non-statistically significant difference between the Intervention and the Comparator. In addition, we include, if any, the number of synthesis papers reporting relevant results but without statistical test of the effects. Details on the quality assessment of the synthesis papers can be found in the methodology section of this WIKI.
Out of the 31 selected synthesis papers, 29 included studies conducted in Europe, and 27 have a quality score higher than 50%.
Table 1: Summary of effects. Number of synthesis papers reporting positive, negative or non-statistically significant effects on environmental and climate impacts. The number of synthesis papers reporting relevant results but without statistical test of the effects are also provided. When not all the synthesis papers reporting an effect are of high quality, the number of synthesis papers with a quality score of at least 50% is indicated in parentheses. Some synthesis papers may report effects for more than one impact, or more than one effect for the same impact.
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| Statistically tested | Non-statistically tested | ||
Impact | Metric | Intervention | Comparator | Significantly positive | Significantly negative | Non-significant | |
Decrease Acidification (LCA) | Acidification | Organic cropping systems | Conventional | 0 | 0 | 1 | 1 |
Organic livestock products | Conventional | 0 | 1 | 1 | 1 | ||
Organic systems | Conventional | 0 | 0 | 2 | 0 | ||
Decrease Air pollutants emissions | Ammonia emission per unit of area | Organic systems | Conventional | 0 | 0 | 1 | 0 |
Decrease Air pollutants emissions | Ammonia emission per unit of product | Organic systems | Conventional | 0 | 0 | 1 | 0 |
Increase Biodiversity | Biodiversity per unit of area | Organic cropping systems | Conventional | 6 | 0 | 2 | 1 (0) |
Organic systems | Conventional | 3 | 0 | 0 | 0 | ||
Increase Carbon sequestration | Carbon sequestration per unit of area | Organic cropping systems | Conventional | 5 (4) | 1 | 0 | 1 (0) |
Organic livestock products | Conventional | 1 | 0 | 0 | 0 | ||
Organic mixed farming systems | Conventional | 1 | 0 | 1 | 0 | ||
Organic systems | Conventional | 3 | 0 | 0 | 0 | ||
Decrease Energy use (LCA) | Energy use per unit of product | Organic cropping systems | Conventional | 2 | 2 (1) | 2 (1) | 1 |
Organic livestock products | Conventional | 1 | 0 | 2 (1) | 1 | ||
Organic systems | Conventional | 1 | 0 | 0 | 0 | ||
Decrease Eutrophication (LCA) | Eutrophication potential per unit of product | Organic cropping systems | Conventional | 0 | 1 | 1 | 1 |
Organic livestock products | Conventional | 0 | 1 | 1 | 1 | ||
Organic systems | Conventional | 0 | 0 | 1 | 0 | ||
Decrease GHG emissions | CH4 emission per unit of area | Organic cropping systems | Conventional | 1 | 0 | 0 | 1 |
Decrease GHG emissions | CH4 emission per unit of product | Organic cropping systems | Conventional | 1 | 0 | 0 | 1 |
Decrease GHG emissions | N2O emission per unit of area | Organic cropping systems | Conventional | 1 | 0 | 0 | 1 |
Organic systems | Conventional | 1 | 0 | 0 | 0 | ||
Decrease GHG emissions | N2O emission per unit of product | Organic cropping systems | Conventional | 0 | 1 | 0 | 1 |
Organic systems | Conventional | 0 | 0 | 1 | 0 | ||
Decrease Global warming potential (LCA) | GWP CH4 emission area based | Organic mixed farming systems | Conventional | 1 | 0 | 0 | 0 |
Decrease Global warming potential (LCA) | GWP N2O emission area based | Organic mixed farming systems | Conventional | 1 | 0 | 0 | 0 |
Decrease Global warming potential (LCA) | GWP area based | Organic mixed farming systems | Conventional | 1 | 0 | 0 | 0 |
Decrease Global warming potential (LCA) | GWP product based | Organic cropping systems | Conventional | 1 | 0 | 2 (1) | 1 |
Organic livestock products | Conventional | 0 | 1 (0) | 2 (1) | 1 | ||
Organic mixed farming systems | Conventional | 0 | 0 | 1 | 0 | ||
Organic systems | Conventional | 0 | 0 | 2 | 0 | ||
Decrease Land use (LCA) | Agricultural land use per unit of product | Organic cropping systems | Conventional | 0 | 2 | 0 | 1 |
Organic livestock products | Conventional | 0 | 1 | 0 | 1 | ||
Increase Land use (LCA) | Agricultural land use per unit of product | Organic systems | Conventional | 0 | 2 | 0 | 0 |
Decrease Nutrient leaching and run-off | N losses per unit of area | Organic mixed farming systems | Conventional | 0 | 0 | 1 | 0 |
Organic systems | Conventional | 2 | 0 | 0 | 0 | ||
Decrease Nutrient leaching and run-off | N losses per unit of product | Organic systems | Conventional | 0 | 1 | 1 | 0 |
Decrease Nutrient leaching and run-off | P losses per unit of area | Organic systems | Conventional | 0 | 0 | 2 | 0 |
Decrease Pests and diseases | Natural enemies of pests per unit of area | Organic cropping systems | Conventional | 3 | 0 | 1 | 0 |
Decrease Pests and diseases | Pests per unit of area | Organic cropping systems | Conventional | 0 | 2 | 0 | 0 |
Increase Pollination | Pollination | Organic cropping systems | Conventional | 1 | 0 | 0 | 0 |
Increase Soil biological quality | Soil biological quality | Organic systems | Conventional | 1 | 1 | 1 | 1 (0) |
Increase Soil nutrients | Soil nutrients per unit of area | Organic cropping systems | Conventional | 0 | 0 | 0 | 1 (0) |
Increase Crop yield | Crop yield | Organic cropping systems | Conventional | 0 | 9 | 2 | 0 |
Organic systems | Conventional | 0 | 0 | 0 | 1 | ||
Increase Crop yield | Crop yield stability | Organic cropping systems | Conventional | 0 | 1 | 2 | 0 |
3. FACTORS INFLUENCING THE EFFECTS ON CLIMATE AND ENVIRONMENTAL IMPACTS
The factors significantly influencing the size and/or direction of the effects on the impacts, according to the synthesis papers included in this review, are reported below. Details about the factors can be found in the summaries of the meta-analyses available in this WIKI.
Table 2: List of factors reported to significantly affect the size and/or direction of the effects on environmental and climate impacts, according to the synthesis papers reviewed. The reference number of the synthesis papers where those factors are explored is given in parentheses.
Impact | Factors |
Biodiversity | Addition of compost (Ref5), Crop field size (Ref4), Crop type (Ref19), Diversity of cover crops (Ref5), Experiment scale (Ref17), Herbicide application (Ref5), Landscape structure and heterogeneity (Ref31), Organism group (Ref19), Pest management strategies (Ref5), Proportion of arable land in the surrounding landscape (Ref19) and Taxon (Ref23) |
Carbon sequestration | C input (Ref21), Clay concentrations in soils (Ref25), Climate (Ref8), Crop residues incorporation (Ref30), Crop rotation (Ref25), Crop type (Ref7), External C input (Ref25), External C inputs (Ref25), External N input (Ref25), Fertilisation intensity (Ref8), Input of organic matter (Ref27), Land use type (Ref30), Legume forages (Ref25), Mean annual precipitation (Ref25), Mean annual temperature (Ref25), Organic input (Ref30), Plough depth (Ref30), Presence of leys in the rotation (Ref27), Region (or certification guidelines) (Ref7) and Soil disturbance (Ref21) |
Energy use (LCA) | Cropping pattern (Ref15), Data sample size (Ref15), Production of mineral fertilisers (Ref27) and Type of product (Ref15) |
GHG emissions | Per unit of field area: Positive; Per unit of product: Negative. (Ref18) |
Global warming potential (LCA) | Product/area unit (Ref15) |
Nutrient leaching and run-off | C/N ratio of fertilisers (Ref30), Crop diversification strategies (Ref30), Fertilisation regime (Ref30), Livestock density (Ref30) and Nitrogen input (Ref27) |
Pests and diseases | Crop field size (Ref4), Crop type (Ref28, Ref10), Experiment scale (Ref28), Pests type (Ref28), Presence of pest management (Ref28) and Study type (Ref10) |
Pollination | Crop field size (Ref4) |
Soil biological quality | Diversification strategies (Ref3), Fertilisation (Ref3), Pesticides use (Ref3) and Tillage (Ref3) |
Crop yield | Best practices (Ref26), Crop diversification strategies (Ref16), Fertilisation (Ref1), Fertilisation regime (Ref9), Negative effect (Ref4), Nitrogen input (Ref26), Soil pH (Ref26), Type of crop (Ref26) and Water management (Ref26) |
4. SYSTEMATIC REVIEW SEARCH STRATEGY
Table 3: Systematic review search strategy - methodology and search parameters.
Parameter | Details |
Keywords | WOS: |
Time reference | No time restriction. |
Databases | Web of Science and Scopus: run on 01 October 2021 |
Exclusion criteria | The main criteria that led to the exclusion of a synthesis paper are: |
5. SYNTHESIS PAPERS INCLUDED IN THE REVIEW
Table 4: List of synthesis papers included in this review. More details can be found in the summaries of the meta-analyses.
Ref Num | Author(s) | Year | Title | Journal | DOI |
Ref1 | Alvarez, R | 2022 | Comparing Productivity of Organic and Conventional Farming Systems: A Quantitative Review | ARCHIVES OF AGRONOMY AND SOIL SCIENCE | 10.1080/03650340.2021.1946040 |
Ref2 | Alvarez, R | 2021 | Organic farming does not increase soil organic carbon compared to conventional farming if there is no carbon transfer from other agroecosystems. A meta-analysis | Soil Research 60(3) 211-223 | 10.1071/SR21098 |
Ref3 | Puissant, J; Villenave, C; Chauvin, C; Plassard, C; Blanchart, E; Trap, J | 2021 | Quantification of the global impact of agricultural practices on soil nematodes: A meta-analysis | SOIL BIOLOGY & BIOCHEMISTRY, 161, 108383 | 10.1016/j.soilbio.2021.108383 |
Ref4 | Smith, OM; Cohen, AL; Reganold, JP; Jones, MS; Orpet, RJ; Taylor, JM; Thurman, JH; Cornell, KA; Olsson, RL; Ge, Y; Kennedy, CM; Crowder, DW | 2020 | Landscape context affects the sustainability of organic farming systems | PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 117 6, 2870-2878 | 10.1073/pnas.1906909117 |
Ref5 | Doring, J; Collins, C; Frisch, M; Kauer, R | 2019 | Organic and Biodynamic Viticulture Affect Biodiversity and Properties of Vine and Wine: A Systematic Quantitative Review | AMERICAN JOURNAL OF ENOLOGY AND VITICULTURE 70 3, 221-242 | 10.5344/ajev.2019.18047 |
Ref6 | Katayama, N; Bouam, I; Koshida, C; Baba, YG | 2019 | Biodiversity and yield under different land-use types in orchard/vineyard landscapes: A meta-analysis. | Biological Conservation 229: 125-133. | 10.1016/j.biocon.2018.11.020 |
Ref7 | Smith, OM; Cohen, AL; Rieser, CJ; Davis, AG; Taylor, JM; Adesanya, AW; Jones, MS; Meier, AR; Reganold, JP; Orpet, RJ; Northfield, TD; Crowder, DW | 2019 | Organic Farming Provides Reliable Environmental Benefits but Increases Variability in Crop Yields: A Global Meta-Analysis | FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 3 | 10.3389/fsufs.2019.00082 |
Ref8 | Garcia-Palacios, P; Gattinger, A; Bracht-Jorgensen, H; Brussaard, L; Carvalho, F; Castro, H; Clement, JC; De Deyn, G; D'Hertefeldt, T; Foulquier, A; Hedlund, K; Lavorel, S; Legay, N; Lori, M; Mader, P; Martinez-Garcia, LB; da Silva, P; Muller, A; Nascimento, E; Reis, F; Symanczik, S; Sousa, J; Milla, R. | 2018 | Crop traits drive soil carbon sequestration under organic farming | Journal of Applied Ecology 30, 1–10. | 10.1111/1365-2664.13113 |
Ref9 | Knapp, S; van der Heijden, MGA. | 2018 | A global meta-analysis of yield stability in organic and conservation agriculture. | NATURE COMMUNICATIONS 9, 3632 | 10.1038/s41467-018-05956-1 |
Ref10 | Muneret, L; Mitchell, M; Seufert, V; Aviron, S; Djoudi, E; Petillon, J; Plantegenest, M; Thiery, D; Rusch, A. | 2018 | Evidence that organic farming promotes pest control | Nature Sustainability 1, 361-368 | 10.1038/s41893-018-0102-4 |
Ref11 | Clark, M; Tilman, D. | 2017 | Comparative analysis of environmental impacts of agricultural production systems, agricultural input efficiency, and food choice. | ENVIRONMENTAL RESEARCH LETTERS 12 6 | 10.1088/1748-9326/aa6cd5 |
Ref12 | Lesur-Dumoulin, C; Malezieux, E; Ben-Ari, T; Langlais, C; Makowski, D. | 2017 | Lower average yields but similar yield variability in organic versus conventional horticulture. A meta-analysis. | Agronomy for Sustainable Development 37, 45 | 10.1007/s13593-017-0455-5 |
Ref13 | Lichtenberg, EM; Kennedy, CM; Kremen, C; Batary, P; Berendse, F; Bommarco, R; Bosque-Perez, NA; Carvalheiro, LG; Snyder, WE; Williams, NM; Winfree, R; Klatt, BK; Astrom, S; Benjamin, F; Brittain, C; Chaplin-Kramer, R; Clough, Y; Danforth, B; Diekotter, T; Eigenbrode, SD; Ekroos, J; Elle, E; Freitas, BM; Fukuda, Y; Gaines-Day, HR; Grab, H; Gratton, C; Holzschuh, A; Isaacs, R; Isaia, M; Jha, S; Jonason, D; Jones, VP; Klein, AM; Krauss, J; Letourneau, DK; Macfadyen, S; Mallinger, RE; Martin, EA; Martinez, E; Memmott, J; Morandin, L; Neame, L; Otieno, M; Park, MG; Pfiffner, L; Pocock, MJO; Ponce, C; Potts, SG; Poveda, K; Ramos, M; Rosenheim, JA; Rundlof, M; Sardinas, H; Saunders, ME; Schon, NL; Sciligo, AR; Sidhu, CS; Steffan-Dewenter, I; Tscharntke, T; Vesely, M; Weisser, WW; Wilson, JK; Crowder, DW. | 2017 | A global synthesis of the effects of diversified farming systems on arthropod diversity within fields and across agricultural landscapes. | 23, 11, 4946-4957. | 10.1111/gcb.13714 |
Ref14 | Kopittke, PM; Dalal RC; Finn D; Menzies NW | 2016 | Global changes in soil stocks of carbon, nitrogen, phosphorus, and sulphur as influenced by long‐term agricultural production. | Global change biology 23, 2509-2519 | 10.1111/gcb.13513 |
Ref15 | Lee K.S., Choe Y.C., Park S.H. | 2015 | Measuring the environmental effects of organic farming: A meta-analysis of structural variables in empirical research | JOURNAL OF ENVIRONMENTAL MANAGEMENT 162, 263-274. | 10.1016/j.jenvman.2015.07.021 |
Ref16 | Ponisio, LC; M'Gonigle, LK; Mace, KC; Palomino, J; de Valpine, P; Kremen, C | 2015 | Diversification practices reduce organic to conventional yield gap | Proc. R. Soc. B 282, 20141396 | 10.1098/rspb.2014.1396 |
Ref17 | Montañez, MN; Amarillo-Suárez, A. | 2014 | Impact of organic crops on the diversity of insects: a review of recent research. | Revista Colombiana de Entomología 40: 131 - 142. | www.scielo.org.co/scielo.php?pid=S0120-04882014000200001&script=sci_abstract |
Ref18 | Skinner, C; Gattinger, A; Muller, A; Mader, P; Fliessbach, A; Stolze, M; Ruser, R; Niggli, U. | 2014 | Greenhouse gas fluxes from agricultural soils under organic and non-organic management - A global meta-analysis | Science of the Total Environment 468–469, 553–563 | 10.1016/j.scitotenv.2013.08.098 |
Ref19 | Tuck, SL; Winqvist, C; Mota, F; Ahnstrom, J; Turnbull, LA; Bengtsson, J. | 2014 | Land-use intensity and the effects of organic farming on biodiversity: a hierarchical meta-analysis. | Journal of Applied Ecology 51: 746-755. | 10.1111/1365-2664.12219 |
Ref20 | Ugarte, CM; Kwon, H; Andrews, SS; Wander, MM. | 2014 | A meta-analysis of soil organic matter response to soil management practices: An approach to evaluate conservation indicators | Journal of soil and water conservation 69, 422-430 | 10.2489/jswc.69.5.422 |
Ref21 | Aguilera, E; Lassaletta, L; Gattinger, A; Gimeno, BS. | 2013 | Managing soil carbon for climate change mitigation and adaptation in Mediterranean cropping systems: A meta-analysis | AGRICULTURE ECOSYSTEMS & ENVIRONMENT 168, 25-36. | 10.1016/j.agee.2013.02.003 |
Ref22 | Wilcox, JC; Barbottin, A; Durant, D; Tichit, M; Makowski, D. | 2013 | Farmland Birds and Arable Farming, a Meta-Analysis. | Sustainable Agriculture Reviews 13: 35-63. | 10.1007/978-3-319-00915-5_3 |
Ref23 | Crowder, DW; Northfield, TD; Gomulkiewicz, R; Snyder, WE. | 2012 | Conserving and promoting evenness: organic farming and fire-based wildland management as case studies. | Ecology 93: 2001–2007. | 10.1890/12-0110.1 |
Ref24 | de Ponti T., Rijk B., van Ittersum M.K. | 2012 | The crop yield gap between organic and conventional agriculture. | AGRICULTURAL SYSTEMS 108, 1–9 | 10.1016/j.agsy.2011.12.004 |
Ref25 | Gattinger A; Muller A; Haeni M; Skinner C; Fliessbach A; Buchmann N; Mäder P; Stolze M; Smith P; El-Hage Scialabba N; Niggli U. | 2012 | Enhanced top soil carbon stocks under organic farming | PNAS 109 (44), 18226-18231. | 10.1073/pnas.1209429109 |
Ref26 | Seufert, V; Ramankutty, N; Foley, JA | 2012 | Comparing the yields of organic and conventional agriculture | NATURE 485, 229–232. | 10.1038/nature11069 |
Ref27 | Tuomisto HL; Hodge ID; Riordana P; Macdonald DW | 2012 | Does organic farming reduce environmental impacts? – A meta-analysis of European research | Journal of Environmental Management 112, 309-320 | 10.1016/j.jenvman.2012.08.018 |
Ref28 | Garratt, MPD; Wright, DJ; Leather, SR. | 2011 | The effects of farming system and fertilisers on pests and natural enemies: A synthesis of current research | AGRICULTURE ECOSYSTEMS & ENVIRONMENT 141, 261-270. | 10.1016/j.agee.2011.03.014 |
Ref29 | Kaschuk, G; Alberton, O; Hungria, M. | 2010 | Three decades of soil microbial biomass studies in Brazilian ecosystems: Lessons learned about soil quality and indications for improving sustainability. | Soil Biology & Biochemistry 42: 1–13. | 10.1016/j.soilbio.2009.08.020 |
Ref30 | Mondelaers, K; Aertsens, J; Van Huylenbroeck, G. | 2009 | A meta-analysis of the differences in environmental impacts between organic and conventional farming | BRITISH FOOD JOURNAL 111 10, 1098-1119 | 10.1108/00070700910992925 |
Ref31 | Bengtsson, J; Ahnstrom, J; Weibull, AC. | 2005 | The effects of organic agriculture on biodiversity and abundance: a meta-analysis. | Journal of Applied Ecology 42: 261-269. | 10.1111/j.1365-2664.2005.01005.x |
Disclaimer: These fiches present a large amount of scientific knowledge synthesised to assess farming practices impacts on the environment, climate and productivity. The European Commission maintains this WIKI to enhance public access to information about its initiatives. Our goal is to keep this information timely and accurate. If errors are brought to our attention, we will try to correct them. However, the Commission accepts no responsibility or liability whatsoever with regard to the information on these fiches and WIKI.
[1] Synthesis research papers include either meta-analysis or systematic reviews with quantitative results. Details can be found in the methodology section of the WIKI.
[2] https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32018R0848&from=EN
[3] https://doi.org/10.1016/B0-12-227050-9/00235-0 and https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/organic-farming-system
[4] https://doi.org/ 10.1080/03650340.2021.1946040