Contaminated Sludge Cake Experiment
- Experiment Code: W/CS/427
- Experiment Site: Woburn
- Objectives: To test the effect of zinc, copper and cadmium enriched sewage sludges on soil microbial activity and agricultural productivity.
- Description: Enables the comparison of different sewage sludge processing (digested versus undigested), metal concentrations (zinc, copper and cadmium) at four rates up to EU limits and period of application (short term versus long-term). All had the same amount of organic matter added. Samples of the sludge used and periodic soil and plant samples are available in the Rothamsted Sample Archive. This experiment is part of a network of 9 sites across the UK and can also be compared with related Metal Amended Liquid Sludge Experiment and Metal Salts Experiment, also at Woburn.
- Date Start: 1994
- Date End: Ongoing
Key Contacts
Steve McGrath
- Role: Principal Investigator
- Organisation: Rothamsted Research
- Address: West Common, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom
Funding
- The e-RA database, including the published datasets generated from it, is part of the Rothamsted Long-Term Experiments - National Bioscience Research Infrastructure (RLTE-NBRI) , which also includes the Long-Term Experiments, the Sample Archive and Rothamsted's environmental monitoring activities including the weather stations and its role in the UK Environmental Change Network.
- The RLTE-NBRI is supported by the Lawes Agricultural Trust and the Biotechnology and Biological Sciences Research Council (Grants BBS/E/C/00005189 (2012-2017); BBS/E/C/000J0300 (2017-2022); BBS/E/RH/23NB0007 (2023-2028)).
Experimental Design
Description
- Five types of sewage sludge cake were applied: 1. Digested low metal sludge 2. Digested sludges with 1 of 4 rates of zinc contamination 3. Undigested sludges with 1 of 4 rates of copper contamination 4. Digested sludges with 1 of 4 rates of cadmium contamination 5. Undigested low metal sludge Sludges were applied in two different ways, as short-term treatments applied in four large applications between 1994 and 1997 or as long-term treatments of annual applications between 1994 and 2014 of approximately 1/25th of the amounts of the same sludges to realize the same total dose of metal application as in the short term treatments in 25 years.
Design
- Period: 1994 - Now
- Number of Blocks: 3
- Number of Plots: 63
- Number of Harvests per Year: 1
Crops
| Crop | Years Grown |
|---|---|
| Wheat |
Factors
Factors are the interventions or treatments which vary across the experiment.
Zinc Nutrient Exposure
Description: Applied with digested sludge
Application: Whole Plot
Levels
| Level Name | Amount | Years | Frequency | Crop | Method | Chemical Form | Notes |
|---|---|---|---|---|---|---|---|
| Rate 1 | 254 kg/ha | 1994 - 1997 | annually | ||||
| Rate 2 | 514 kg/ha | 1994 - 1997 | annually | ||||
| Rate 3 | 784 kg/ha | 1994 - 1997 | annually | ||||
| Rate 4 | 1065 kg/ha | 1994 - 1997 | annually | ||||
| Low Rate | 15 kg/ha | 1994 - 2014 | annually |
Copper Nutrient Exposure
Description: Applied with undigested sludge
Application: Whole Plot
Levels
| Level Name | Amount | Years | Frequency | Crop | Method | Chemical Form | Notes |
|---|---|---|---|---|---|---|---|
| Rate 1 | 125 kg/ha | 1994 - 1997 | annually | ||||
| Rate 2 | 245 kg/ha | 1994 - 1997 | annually | ||||
| Rate 3 | 375 kg/ha | 1994 - 1997 | annually | ||||
| Rate 4 | 500 kg/ha | 1994 - 1997 | annually | ||||
| Low Rate | 7.5 kg/ha | 1994 - 2014 | annually |
Cadmium Exposure
Description: applied with digested sludge
Application: Whole Plot
Levels
| Level Name | Amount | Years | Frequency | Crop | Method | Chemical Form | Notes |
|---|---|---|---|---|---|---|---|
| Rate 1 | 2.15 kg/ha | 1994 - 1997 | annually | ||||
| Rate 2 | 4.64 kg/ha | 1994 - 1997 | annually | ||||
| Rate 3 | 7.22 kg/ha | 1994 - 1997 | annually | ||||
| Rate 4 | 9.72 kg/ha | 1994 - 1997 | annually | ||||
| Low Rate | 0.15 kg/ha | 1994 - 2014 | annually |
Factor Combinations
Factor Combinations are the combination of factors applied to different plots on the experiment.
| Factor Combination | Time Coverage | Notes |
|---|---|---|
| Cc +Cu | - |
Site: Butt Close West - Woburn
- Experiment Site: Woburn
- Management: Mineral fertilisers added every year. Plots were bounded by permanent grass strips to prevent soil movement during cultivation. Cultivations were carried out annually to ensure that the sludge additions were evenly incorporated in the top 0-25cm and to encourage organic matter breakdown of the sludge cakes. The soil pH was maintained at 6.5.
- Visit Permitted?: No
- Elevation: 96 Metres
- Geolocation: 52.01195, -0.597963
Soil
- Type: Arenosol
Soil Properties
| Variable | Value | Reference Year | Is Estimated | Is Baseline |
|---|---|---|---|---|
| Sand content | 80% (Percent) | 1994 | NO | YES |
| Silt content | 12% (Percent) | 1994 | NO | YES |
| Clay content | 8% (Percent) | 1994 | NO | YES |
| Soil pH | 7.2 () | 1994 | NO | YES |
| Soil organic carbon | 1.3% (Percent) | 1994 | NO | YES |
There are currently no prepared datasets online for this experiment. However,
there may still be data available but requiring curation.
For more information please contact the e-RA curators.
License
These media (images and videos) are
available under a Creative Commons
Attribution Licence (4.0) with attribution to Rothamsted Research.
Images
Key References
NO KEYREF PROVIDED
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For further information and assistance, please contact the e-RA curators, Sarah Perryman and Margaret Glendining using the e-RA email address: era@rothamsted.ac.uk