Contaminated sludge cake experiment
- Local identifier
- W/CS/427
- Years operational
- 1994—
- Objective
- 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.
- Data Access Statement
- Other
- Data license
- Other
- Data policy
- Yes (not online)
- Organizations
- Rothamsted Researchresearch organisationWoburn Experimental Farmexperimental research station
- Person
- Prof. Steve McGrathprincipal investigatorRothamsted ResearchSustainable Agricultural Sciences
Site: Butt Close West
- Type
- research station field
- Location
- Husborne CrawleyBedfordshireUnited Kingdom
- Geographic location
- 52.01195, -0.597963
- Elevation
- 96 Metres
- Visits permitted?
- No
- 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.
- Soil type
- arenosol
- Soil properties
Variable Depth Value (range) Units Ref year Estimated? Baseline? sand content 0 – 25 Centimetres 80 Percent 1994 silt content 0 – 25 Centimetres 12 Percent 1994 clay content 0 – 25 Centimetres 8 Percent 1994 soil pH 0 – 25 Centimetres 7.2 1994 soil organic carbon 0 – 25 Centimetres 1.3 Percent 1994 - Climatic type
- temperate oceanic climate
Design period: (1994—)
- Description
- Plots measured 6 x 8m
- 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.
- Number of blocks
- 3
- Number of plots
- 63
- Number of harvests per year
- 1
- Crop
Crop Years grown wheat - Factors
- Factor name
- Factor levels
- zinc nutrient exposure Applied with digested sludgePlot application: Whole plotEffect: Residual
Rate 1 (254 kg/ha)
1994—1997Applied to crop: All cropsApplication frequency: annuallyRate 2 (514 kg/ha)
1994—1997Application frequency: annuallyRate 3 (784 kg/ha)
1994—1997Application frequency: annuallyRate 4 (1065 kg/ha)
1994—1997Application frequency: annuallylow rate (15 kg/ha)
1994—2014Application frequency: annually- copper nutrient exposure Applied with undigested sludgePlot application: Whole plot
Rate 1 (125 kg/ha)
1994—1997Application frequency: annuallyRate 2 (245 kg/ha)
1994—1997Application frequency: annuallyRate 3 (375 kg/ha)
1994—1997Application frequency: annuallyRate 4 (500 kg/ha)
1994—1997Application frequency: annuallylow rate (7.5 kg/ha)
1994—2014Application frequency: annually- cadmium exposure applied with digested sludgePlot application: Whole plot
Rate 1 (2.15 kg/ha)
1994—1997Application frequency: annuallyRate 2 (4.64 kg/ha)
1994—1997Application frequency: annuallyRate 3 (7.22 kg/ha)
1994—1997Application frequency: annuallyRate 4 (9.72 kg/ha)
1994—1997Application frequency: annuallylow rate (0.15 kg/ha)
1994—2014Application frequency: annually
- Factor combinations
- Cc +Cu
- copper nutrient exposure: Rate 1cadmium exposure: Rate 1
Related publications
- Gibbs, P. A. , Chambers, B. J. , Chaudri, A. M. , McGrath, S. P. , Carlton-Smith, C. H. , Bacon, J. R. , Campbell, C. D. and Aitken, M. N. (2006) "Initial results from a long-term, multi-site field study of the effects on soil fertility and microbial activity of sludge cakes containing heavy metals", Soil Use and Management, 22, 11-21 https://doi.org/10.1111/j.1475-2743.2006.00003.x [In English]
- Charlton, A. , Sakrabani, R. , McGrath, S. P. and Campbell, C. D. (2016) "Long-term Impact of Sewage Sludge Application on Rhizobium leguminosarum biovar trifolii: An Evaluation Using Meta-Analysis", Journal of Environmental Quality, 45, 1572-1587 https://doi.org/10.2134/jeq2015.12.0590 [In English]
- McGrath, S. P. , Chambers, B. J. , Taylor, M. J. and Carlton-Smith, C. H. (2012) "Biofortification of zinc in wheat grain by the application of sewage sludge", Plant and Soil, 361, 97-108 httpsL//doi.org/10.1007/s11104-012-1381-6 [In English]
- Macdonald, C. A. , Clark, I. M. , Zhao, F.-J. , Hirsch, P. R. , Singh, B. K. and McGrath, S. P. (2011) "Long-term impacts of zinc and copper enriched sewage sludge additions on bacterial, archaeal and fungal communities in arable and grassland soils", Soil Biology & Biochemistry, 43, 932-941 https://doi.org/10.1016/j.soilbio.2011.01.004 [In English]
- Chaudri, A. , McGrath, S. , Gibbs, P. , Chambers, B. , Carlton-Smith, C. , Bacon, J. , Campbell, C. and Aitken, M. (2008) "Population size of indigenous Rhizobium leguminosarum biovar trifolii in long-term field experiments with sewage sludge cake, metal-amended liquid sludge or metal salts: Effects of zinc, copper and cadmium", Soil Biology & Biochemistry, 40, 1670-1680 https://doi.org/10.1016/j.soilbio.2008.01.026 [In English]