National Soil Monitoring Network: Review and Assessment Study
December 2006


Project funders/partners: SNIFFER, Environment Agency, Defra, Scottish Environment Protection Agency, Scottish Natural Heritage, Scottish Executive

Background and objectives  to research

The ultimate aims of the UK-Soil Indicators Consortium (UK-SIC) are to identify indicators of soil quality for soil monitoring and to develop a UK monitoring scheme that:
 SNIFFER Project LQ09 sits mid-way between these two stages with the objective of informing the development of a subsequent project whose purpose will be to design a UK soil monitoring scheme. The primary objectives of Project LQ09 were to carry out a stocktaking exercise of all environmental monitoring schemes currently in place (UK and EU) which might be useful in the context of soil monitoring and to assess whether these existing monitoring schemes could fit into a UK network for soil monitoring, highlighting data and spatial gaps and recommending improvements that could be made.

The main activities of LQ09 were to construct a catalogue of existing schemes and to code these against standardised criteria reflecting the scheme’s potential value for a soil monitoring scheme able to report at a UK and devolved administration level. Of particular interest was whether schemes included indicators of soil quality currently being considered by the UK-Soil Indicators Consortium (UK-SIC indicators).  An analysis of the strengths and weaknesses of each scheme was undertaken and generic weaknesses / gaps were identified. The potential for adapting and/or combining current schemes to deliver a UK soil monitoring scheme was also investigated.

Key findings and recommendations
1. A total of 29 schemes were considered of relevance to these objectives and were included in the catalogue. Scheme entries were analysed using a coding scheme to provide an overview of current scheme attributes and to identify possible opportunities to integrate or adapt schemes to deliver a UK soil monitoring scheme. Attributes considered were; soil parameters, analytes and functions covered; ability to report and assess trends; statistical design; coverage spatially, vertically and temporally; data quality; availability of reports, data and samples and integration issues.

2. Key findings were: (i) Current schemes could be divided into three broad categories: spatial surveys (e.g. Countryside Survey (CS) and the National Soil Inventories (NSIs)), networks (e.g. Environmental Change Network (ECN), Level II Intensive Monitoring of Forest Ecosystems (Level II)) and long term experimental or monitoring sites (e.g. the Rothamsted experiment). (ii) Only four schemes included urban areas. (iii) The majority of schemes started in the 1990s and for this reason, very few spatial surveys (except the NSIs, CS and the Representative Soil Sampling Scheme (RSSS)) have a repeat cycle of measurements. (iv) All schemes hold data in digital form and most have free or licensed access (with or without a fee) (v) All schemes have data available on one or more of the 15 UK-SIC indicators currently being considered for a minimum dataset while most GB or devolved administration level schemes have data available for 9 or more of the minimum dataset (vi) Major gaps in current schemes were identified as; relatively few or no data for three UK-SIC indicators currently being considered for a minimum datset; a lack of consistency in type and depth of sample taken and sampling procedure; a lack of consistency in methods of analysis; and a limited number of soil physical measurements. (vii) Some schemes, whilst having a statistical design appropriate for their purpose, do not have a design appropriate for a UK monitoring scheme

3. The consortium concluded that whilst the UK is rich in soils data at a range of relevant spatial and temporal scales, it is not possible to integrate and/or combine existing schemes to deliver the full requirements of a UK soil monitoring scheme due to problems with differences in methodology and timing of sampling. However, current schemes could provide a framework to establish a new scheme whilst providing information on indicators of soil quality during a transition period. Existing schemes could also provide data to help interpret and understand any changes observed whilst running alongside a new UK scheme. A second option would be to select one of the existing schemes operating at devolved administration or GB level with the recommended statistical design and to expand it to report for all soil indicators at UK and devolved administration levels with the required contextual information. Whatever approach is taken, the exact purpose and required outcomes of a UK-scale soil monitoring scheme will need to be carefully specified to ensure that the design meets all expectations and needs.

4. The consortium recommends that any new UK scheme should contain two distinct elements.  Firstly, a surveillance element with broad spatial coverage would need to be designed to allow changes of specific sizes in specific regions to be detected with known power.   This element would have to be statistically robust and be capable of detecting changes as a result of changing land use / cover patterns.  Sampling locations could either be grid-based or random but in either case a known sampling frame would be required. One option in any new UK monitoring scheme might be to adopt a rotating panel design in which sampling locations are dropped after a period of time to ensure representativeness of the population for which inferences are required.  Secondly, contextual information would be required to allow changes measured by the surveillance element to be understood and interpreted.  Without this second element, the causes and hence policy implications of changes detected by the surveillance element would be open to challenge.

Key words: soil, monitoring, indicators, soil carbon, UK-SIC, soil function, soil threats

Copies of this report are available from the Foundation, in electronic format on CDRom at 20.00 + VAT or hard copy at 25.00, less 20% to FWR members.
N.B. The report is available for download from the SNIFFER Website.