Anaerobic Soil Disinfestation (ASD): Practical Information.
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Anaerobic Soil Disinfestation (ASD) is an alternative method to chemical soil treatments that helps reduce soil-borne diseases, pests, and weeds. The process involves incorporating easily degradable organic material into the soil, then covering it with an airtight plastic film to create anaerobic conditions. As microorganisms decompose the organic matter, they consume oxygen, leading to the production of volatile fatty acids and other toxic compounds that are lethal to many pathogens, parasites, and weeds, without sterilizing the entire soil ecosystem.
The practical application of ASD involves several key steps. First, selecting organic materials that are fresh, easily degradable, and free of pests or seeds, such as crop residues or green manures. Approximately 40 tons per hectare of organic material is required to treat a 40 cm soil depth. The material should be chopped finely to facilitate microbial colonization and oxygen depletion.
Second, the soil must be prepared by ensuring it is at field capacity—meaning sufficiently wet, typically achieved by irrigation if necessary. The organic material is then evenly incorporated into the top 20-40 cm of soil, depending on the target depth. After incorporation, the soil is compacted to reduce large pores, which helps concentrate the volatile compounds produced during fermentation.
Third, the soil surface is covered with a suitable airtight plastic film, such as Virtually Impermeable Films (VIF) or thick polyethylene, to prevent oxygen inflow and maintain anaerobic conditions. The plastic must be inspected regularly for damages or holes, which should be promptly repaired. Additional measures like weighing down the plastic with sandbags and fencing can prevent wind damage and animal disturbance.
ASD is most effective when applied during periods when soil temperatures are above 16°C, and it is recommended to be maintained for 6 to 8 weeks. Proper conditions—moisture, temperature, and airtight coverage—are essential for success. This method tends to work better in sandy soils but is broadly applicable across most soil types.
Overall, ASD offers an environmentally friendly, chemical-free option to manage soil health, reduce pests and pathogens, and improve crop safety, provided that the outlined steps and conditions are carefully followed.
Anaerobic Soil Disinfestation (ASD): Practical Information. (en)
Number of pages: 3
Target countries: Netherlands
Key takeaways
- Anaerobic Soil Disinfestation (ASD) offers an effective alternative to chemical treatments
- ASD reduces soil borne diseases, pests, and weeds by creating an anaerobic environment that depletes oxygen and releases toxic compounds, without sterilizing beneficial micro-organisms.
- Proper conditions are critical for ASD success
- Applying ASD requires soil temperatures above 16°C, adequate soil moisture at field capacity, and incorporation of easily degradable organic material at recommended quantities to ensure effective organic matter degradation and pathogen control.
- Material selection and application practices impact ASD effectiveness
- Using fresh, chopped organic matter and ensuring the plastic cover is airtight with suitable VIF or polyethylene significantly influence the rapid depletion of oxygen and the release of volatile fatty acids necessary for pathogen suppression.
- Surface sealing and environmental protection are essential during ASD
- Chasing animals, repairing holes, and preventing wind damage to the plastic cover are vital steps to maintaining an oxygen-free environment and safe conditions for the duration of 6-8 weeks.
- Higher soil and environmental temperatures improve ASD outcomes
- Applying ASD in periods when soil temperatures exceed 16°C enhances microbial activity and organic matter breakdown, leading to more effective disinfestation.
- Application depth and organic material quantity should be matched
- Disinfestation of soil at greater depths (up to 80 cm) requires proportionally higher quantities of organic material (up to 80 tons/ha) to ensure thorough treatment.
Sources
- Anaerobic Soil Disinfestation (ASD): Practical Information. - - https://www.best4soil.eu/assets/factsheets/2.pdf
