Until now, there are no specific rules for organic greenhouse production. The recently published EGTOP report provides technical advice for the most controversial topics.
A brief summary of their conclusions is:
- Fertility should be supplied primarily from slow release organic fertilisers, such as manures and composts. The use of liquid fertilisers should be justified by calculating nutrient balances.
- Using irrigation to flush out surplus nutrients is not acceptable.
- Crop rotation is desirable, but difficult to implement in greenhouses.
- Soil health should be maintained by preventive methods including rotation and use of biologically active composts. Biofumigation, solarisation and shallow steam treatment of the soil should be allowed. Deep steam treatment (beyond 10 cm) should only be allowed under exceptional circumstances (e.g. nematode infestation).
- Use of natural enemies (beneficial insects) is in line with the principles of organic farming.
- With regard to plant protection, the same substances should be authorised as for use outdoors.
- Cleaning and disinfection should be regulated for plant protection in general, and not only for greenhouse production. The group concluded that there should be a review of the substances allowed for disinfection and/or decalcification in all situations.
- Mulching: Non-biodegradable mulches should be allowed, with re-use and recycling encouraged. Biodegradable mulches are acceptable, with the exception of starch derived from GM crops.
- Irrigation and water use: Guidance for efficient water use and/or water recycling should be developed.
- Energy use: Responsible energy use is needed.
- Light: Use of artificial light is acceptable, although not in excess of the Photosynthetically Active Radiation (PAR) of a summer day and should not exceed 12 hours of daylight including the artificial light.
- Temperature: Due to variation in climate, unified criteria for heating greenhouses cannot be easily applied to different regions in the EU. Efforts should be made to minimise energy consumption and maximise the use of energy from renewable resources.
- Carbon dioxide: CO2 enrichment is acceptable, but should preferably be from processing or burning of biomass sources. Research is needed on alternatives to CO2 enrichment based on burning of fossil fuels, which should not be allowed.
- Growing media: Use of peat in growing media is acceptable, but should be restricted to 80% by volume of growing media, while use of peat as a soil conditioner is not acceptable. Soil from certified areas of organic farms should be allowed to be mixed into substrates for use on the farm itself.
- Growing in substrates: Growing in substrates is acceptable for seedlings and transplants, and for plants sold to the consumer together with the pot/container in which they are grown. Harvesting organic vegetables or fruits from plants grown in substrate cultures is not acceptable, they should be grown in the soil. However, the Group makes an exception for the traditional practice of growing of vegetables in ‘demarcated beds’. This exception is limited to those farms in Finland, Sweden, Norway and Denmark which grew such cultures before 2013, on the condition that the growing media and plastic is recycled.
- Recycling of growing media: Excess growing media from potting, unsold potted plants, or growing media used in demarcated beds should be recycled.
- Conversion periods: For greenhouses, where plants are grown in the soil, conversion periods should be the same as for outdoor cropping. For greenhouses, where plants are grown in substrate with no contact with the soil, no conversion time is required from the technical point of view, if appropriate measures are taken to avoid contamination risks. The group suggests that conversion periods in general should be reviewed, considering a one-year conversion for greenhouse and outdoor crops.
These recommendations will be discussed by the Standing Committee on Organic Farming (SCOF) over the next few months, with the possibility that some or all of the recommendations may be adopted as part of the review of the EU organic regulation currently in progress. This review process provides an opportunity for the entire organic sector to engage in a debate about how the regulations should be developed.
Text: Modified from "Final report on Protected Cropping" (posted September 17, 2013) at the website of the Organic Research Centre Elm Farm, UK (www.organicresearchcentre.com)
- ec.europa.eu: Expert Group for Technical Advice in Organic Production (EGTOP)
- ec.europa.eu: Final Report On Greenhouse Production (Protected Cropping)
- eu.ifoam.org: Position Paper on Organic Greenhouse Production
- ec.europa.eu: Standing Committe on Organic Farming (SCOF)