Metal Amended Liquid Sludge Experiment

Local identifier
W/CS/428
Years operational
1994—2019
Objective
To the effects of zinc, copper and cadmium on soil microbial activity with low organic matter inputs.
Description
Enables the comparison of metal concentrations (zinc, copper and cadmium) at 3 rates in small amounts of organic matter applied as a specially made liquid sludge applied. 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 3 sites across the UK and can also be compared with related Contaminated Sludge Cake Experiment and Metal Salts Experiment, also at Woburn.
Data Access Statement
Available to any researcher on request
Data license
CC BY
Data policy
Yes (not online)
Organizations
Rothamsted Research
research organisation
Woburn Experimental Farm
experimental research station
Person
Prof. Steve McGrath
principal investigator
Rothamsted Research
Sustainable Agricultural Sciences

Site: Butt Close West

Type
research station field
Location
Husborne Crawley
Hertfordshire
United Kingdom
Geographic location
52.01195, -0.597963
© OpenStreetMap contributors
Elevation
96 Metres
Visits permitted?
No
Management
Plots were bounded by wooden boards prevent soil movement during cultivation. Cultivations were carried out annually to ensure that the sludge additions were evenly incorporated in the top 0-25cm. The soil pH was maintained at 6.5.
Soil type
arenosol
Soil properties
VariableDepthValue (range)UnitsRef yearEstimated?Baseline?
sand content0 – 25 Centimetres83 Percent1995
silt content0 – 25 Centimetres8 Percent1995
clay content0 – 25 Centimetres9 Percent1995
soil pH0 – 25 Centimetres7.3 1995
soil organic carbon0 – 25 Centimetres1.1 Percent1995
Climatic type
temperate oceanic climate

Design period: (1995—)

Design Type
Randomized complete block design
Description
The metal amended sludges were prepared by mixing either zinc, copper or cadmium salts with a low metal content liquid digested sludge. . The sludges were applied for 3 years between 1995 and 1997. Plots measured 3.5 x 1.2m
Design description
Each plot received only one of the three metal amendments for 3 years between 1995 and 1997. In addition to the 9 treated plots there were 2 low metal content only sludge treatment plots and 2 untreated/no sludge control plots. All sludge treatments received the same organic matter loading.
Number of blocks
3
Number of plots
39
Number of harvests per year
1
Crop
CropYears grown
rye grass
Factors
Factor name
Factor levels
zinc nutrient exposure
Applied as liquid sludge
Plot application: Whole plot
Rate 1  (348 kg/ha)
1995—1997
Application frequency: annually
Rate 2  (696 kg/ha)
1995—1997
Application frequency: annually
Rate 3  (1094 kg/ha)
1995—1997
Application frequency: annually
copper nutrient exposure
Plot application: Whole plot
Rate 1  (181 kg/ha)
1995—1997
Application frequency: annually
Rate 2  (351 kg/ha)
1995—1997
Application frequency: annually
Rate 3  (523 kg/ha)
1995—1997
Application frequency: annually
cadmium exposure
Plot application: Whole plot
Rate 1  (5.02 kg/ha)
1995—1997
Application frequency: annually
Rate 2  (7.8 kg/ha)
1995—1997
Application frequency: annually
Rate 3  (10.58 kg/ha)
1995—1997
Application frequency: annually

Related publications

  • Gibbs, P. A. , Chambers, B. J. , Chaudri, A. M. , McGrath, S. P. and Carlton-Smith, C. H. (2006) "Initial results from long-term field studies at three sites on the effects of heavy metal-amended liquid sludges on soil microbial activity", Soil Use and Management, 22, 180-187
  • 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