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Extension to WEB (Widescale Enhancement of Biodiversity) BD1466 - BD5208

Grassland is the predominant habitat in the agri-environment schemes associated with Entry Level Stewardship (ELS) and Higher Level Stewardship (HLS). ELS options for low input and very low input grassland (e.g. EK2, EK3) are popular with agreement-holders but because of their simplicity their biodiversity benefits are often very low. Additional measures are needed to inform the development of existing or new ELS or HLS options so that they can consistently achieve modest gains to biodiversity over large areas of land with little or no potential for Biodiversity Action Plan Priority Habitat grassland. In addition new primary objectives within Environmental Stewardship (ES) address natural resource protection such as the integrity and health of soil resource. There is therefore a need to identify opportunities for simultaneous delivery of multiple benefits from ES agreements. There is evidence that increases in plant diversity can deliver a range of benefits including grassland faunal diversity and abundance enhancement, soil structural amelioration and nutrient retention and agronomic value in terms of forage quality. This project is providing evidence that a moderate increase in plant diversity has the potential to deliver these multiple objectives.

Previous research (BD1624) showed that more competitive legume species have a good chance of establishing and persisting in soils with a moderately high P Index (at least 2+), which would make them suitable for use in many agriculturally improved grassland soils. Legume rich swards are likely to provide significant benefits for insects and other fauna and provide landscape pathways that could aid their adaptation to climate change. Legume rich swards are of high nutritional value for livestock and require little or no nitrogen fertiliser. BD1404 showed that increased plant diversity can also increase biomass production and nitrogen content of the forage, which was not just due to higher legume diversity, but to a greater diversity of forbs in general.

Phase 1 of this project (2008-2011) established multi-factorial experiments on grasslands in Devon and Berkshire. Both sites were typical of those entering the low input grassland options of ELS, with severe constraints imposed by soil compaction and absence of desirable plant species. The experimental aim was to develop simple, low cost management prescriptions to enhance biodiversity and ecosystem services. Factors investigated were low cost seed mixture composition (grass only, grass+legume, grass+legume+forb), seed bed preparation (minimal cultivation vs. conventional ploughing), and the type (cut vs. grazed) and intensity (typical vs. summer rested) of management. The response of a wide range of biological, biophysical and agronomic variables were measured, including botanical composition, floral and seed resources, pollinator diversity, invertebrate abundance soil nutrient concentration, bulk density, compaction and nutrient leaching losses, herbage productivity and quality, and live weight gain.

The initial results are highly promising, confirming that it is practical to enhance the diversity of productive grasslands with widely available farm machinery at low cost. Large differences were found in the composition of the plant community between different seed mixtures. This also resulted in significant difference in agronomic output. Deep cultivation had a significant beneficial effect on establishment of sown species. There is also evidence that restrictions to cutting and grazing management drive positive biotic responses of the floral resource, pollinator assemblage and biomass of invertebrates available for farmland birds. However, the effects of management are likely to take longer to fully emerge. Similarly, abiotic responses particularly those relating to soil structure and nutrients, will also take time to manifest themselves. For these reasons it has been agreed with Defra and Natural England to extend the project for a further two years. Phase 2 (2011-2013) will enable a full, integrated assessment of the benefits of the different management prescriptions on biodiversity and ecosystem services over the life of an ELS agreement. Importantly, it will enable greater certainty to be placed in the recommendations and policy guidance emerging from the project.
The overall aim of the WEB project is to inform the development of new or existing Entry Level (ELS) or Higher Level Stewardship scheme (HLS) options to restore or create grassland with modest biodiversity value on large areas of land with little or no potential for BAP PH grassland.

Specific objectives
1. Quantify the success of establishing a range of legume and forb species into seedbeds or into existing grassland to provide pollen, nectar, seed, and spatial/structural heterogeneity.

2. Quantify the effects of creating modest increases in grassland plant diversity on faunal diversity/abundance, forage production and quality, soil properties and nutrient losses.

3. Identify grazing and cutting management practices to enhance biodiversity, minimise pollution and benefit agronomic performance.

4. Liaise with Natural England to produce specifications for new or modified ES options, and detailed guidance for their successful management.
Project Documents
• FRP - Final Report : BD5208 WEB final report   (3587k)
• TPS - Two Page Summary : BD5208 WEB 2 page summary   (272k)
Time-Scale and Cost
From: 2011

To: 2013

Cost: £373,441
Contractor / Funded Organisations
BBSRC Central Office, Natural Environment Research Council
Environmental Stewardship