Abstract
AIM - This study investigated impacts of different organic waste treatment methods on reduction and spread of faecal indicator organisms to food crops in a developing country.
METHODS AND RESULTS - Fresh cattle manure was subjected to three different treatments; anaerobic digestion, burning and composting. E. coli, coliforms and nitrogen content of cattle manure were measured before and after treatment in the amended soil and harvested lettuce. All treatments significantly reduced E. coli and coliform counts but differed in the ratio of E. coli or coliforms to nitrogen. Application of the recommended nitrogen dose of 120
kg ha-1 21 as bioslurry resulted in significantly lower E. coli and coliform contamination of soil than the same nitrogen rate applied as compost or ash. The E. coli content of lettuces grown on soil amended with treated wastes at recommended rates did not differ between treatments but was significantly lower than in lettuces grown on soil amended with untreated manure.
CONCLUSIONS - Treatment of manure before use as an organic fertiliser significantly reduces potential contamination of both soil and food crops with E.coli and coliforms. To best reduce the spread of E. coli from organic fertilizers, manures should be treated by anaerobic digestion.
METHODS AND RESULTS - Fresh cattle manure was subjected to three different treatments; anaerobic digestion, burning and composting. E. coli, coliforms and nitrogen content of cattle manure were measured before and after treatment in the amended soil and harvested lettuce. All treatments significantly reduced E. coli and coliform counts but differed in the ratio of E. coli or coliforms to nitrogen. Application of the recommended nitrogen dose of 120
kg ha-1 21 as bioslurry resulted in significantly lower E. coli and coliform contamination of soil than the same nitrogen rate applied as compost or ash. The E. coli content of lettuces grown on soil amended with treated wastes at recommended rates did not differ between treatments but was significantly lower than in lettuces grown on soil amended with untreated manure.
CONCLUSIONS - Treatment of manure before use as an organic fertiliser significantly reduces potential contamination of both soil and food crops with E.coli and coliforms. To best reduce the spread of E. coli from organic fertilizers, manures should be treated by anaerobic digestion.
| Original language | English |
|---|---|
| Pages (from-to) | 618-632 |
| Number of pages | 15 |
| Journal | Journal of Applied Microbiology |
| Volume | 132 |
| Issue number | 1 |
| Early online date | 23 Jun 2021 |
| DOIs | |
| Publication status | Published - 1 Jan 2022 |
Bibliographical note
ACKNOWLEDGEMENTSWe are grateful for the funding provided by the Federation of European Microbiology Societies (FEMS) and the School of Biological Sciences, University of Aberdeen.
Funding information
Federation of European Microbiological Societies; University of Aberdeen
Open Access via UoA Wiley agreement.
Keywords
- Cattle manure
- anaerobic digestion
- composting
- E. coli
- coliforms
- nitrogen
- lettuce
Access to Document
- Chukwu_etal_JAM_Impacts_of_different_VOR
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