Reversion of arable land to permanent grassland has the potential to contribute to the wildlife, landscape and historic objectives of agri-environment schemes. It can also have significant environment protection benefits by buffering key habitats and watercourses. Arable Reversion is therefore a key element in both the Countryside Stewardship Scheme and in several of the Environmentally Sensitive Area Schemes. Prescriptions are available for the reversion and management of ex-arable land with the objective of creating swards typical of both unimproved and improved grassland. The latter is more often the case where enhancement of landscape or the historic environment are the primary objective. Reversion has been implemented either through a variety of intervention techniques or by encouraging natural regeneration. For the former, approaches to cultivation, seed sourcing and seed mix composition have varied; the latter includes the permanent reversion of swards that have been created through long-term setaside. In all cases, the subsequent sward development will have been influenced by management.
Arable reversion sites with a primarily ecological objective have the potential to create swards containing valuable species and communities which could contribute towards the achievement of various targets within the UK Biodiversity Action Plan, in particular the Habitat Action Plans for lowland calcareous grassland, lowland meadows and coastal and floodplain grazing marsh.
However, arable reversion is an expensive option within the agri-environment programme and there is evidence that the ecological and agricultural value of the restored swards varies significantly; some swards may show little progress towards the target of a diverse or even productive sward - particular problems that occur on some agreements may include poor sward development and ingress of pernicious weeds. It is likely that site and management variables have a significant impact on whether the swards that are produced meet scheme objectives.
There is, therefore, a need for a study to quantify the approaches taken to arable reversion within agri-environment schemes, looking at the extent to which established reversion swards are contributing to scheme objectives; their botanical composition and structure; examining how site and management factors have influenced sward development; and reporting on the benefits arising from different approaches,identifying best practice and quantifying the extent of any problems.
The study will select a random sample of fields with arable reversion agreements under various schemes (these should be at least 5 and preferably 10 years old). It is anticipated that about 120 fields will be sampled, of which about 70 will be under CSS agreement and 50 under ESA agreement. The CSS sample should be drawn nationally, whilst the ESA sample will be drawn from 4-5 selected ESAs where arable reversion is a major objective. It will be possible to stratify the CSS sample to ensure adequate representation of agreements with ecological objectives. For each agreement studied a combination of file information, field surveys and structured telephone interviews will be used to:
1. Determine the techniques used to revert and manage the sward over the period of the agreement. This should include review of initial objectives, where stated, and site factors such as field history, proximity to seed sources and soil nutrient status. Where important, hydrological regimes should be assessed.
2. Using a rapid condition assessment technique to be developed by the contractor and agreed with Defra, assess the composition and structure of the reverted sward, relating the outcome to site and management factors. Copies of several reports will assist with developing protocols and identifying suitable attributes and success criteria: (i) EN Research Report No. 378 (Habitat Restoration Monitoring Handbook) available on the EN website, and (ii) the final reports for Defra R&D projects BD1410 and BD1412 (sent separately by email).
3. Assess the current soil nutrient status of fields within the sample. The contractor should collect a soil sample from each field, to a specified methodology to be agreed with Defra, to be analysed for Hand Texture, Organic Matter content (%) via loss on ignition, Extractable P, K and Mg (mg/l), total N (%) and pH.
4. Evaluate the impacts of each reversion on landscape and historic environment and where appropriate (e.g. reversion to wet grassland), the likely value to birds and other fauna (e.g. from assessment of the presence of nectar sources).
5. Document examples of good and bad practice, illustrating examples with digital photographs.
6. In cases where negative impacts have been identified, analyse why these impacts happened (e.g. problems with establishment or ongoing management) and how they might have been avoided.
The contractor will appoint a project team with proven experience of botanical survey work and analysis as well as experience of landscape and the historic environment. Details (including cv) of field surveyors should be passed to Defra as and when they are appointed to work on the project.
Using the results obtained the report should:
1. Quantify and critically evaluate the approaches taken to objective setting, intervention and aftercare on arable reversion agri-environment agreements.
2. Provide an analysis of the strengths and weaknesses of arable reversion agreements giving an indication of the value for money provided.
3. Present suggestions for improving future agreements and their management, possibly in the form of a decision tree.
The outputs will enable Defra to improve targeting of arable reversion, both in terms of site selection and identification of appropriate intervention and management techniques. This will result in a higher proportion of swards that meet biodiversity and other objectives, providing both Defra and the taxpayer with better value for their investment.
The contract will begin in April, 2003. It is anticipated that in the first year of the project (2003), work will focus on method development with the site assessments taking place in 2004.
A final report should be delivered to Defra before Christmas 2004.