Slug pellets are regulated as pesticides. This means that they may only be sold and used if scientific risk assessments find no harmful effect on people and no unacceptable effects on the environment. Possible effects on wildlife (including earthworms and birds) are considered as part of the environmental assessment. Regulatory decisions are regularly reviewed so that safety can be reassessed using the latest data and scientific knowledge.

A recent review of the substance metaldehyde raised concerns about risks to birds and mammals; the use of slug pellets containing metaldehyde is therefore being phased out. Other slug pellets are based on ferric phosphate; the latest risk assessment of this substance concluded that it met all the safety requirements, including those relating to earthworms and birds.

Defra is working closely with the research councils and is funding research to improve our understanding of the role of soil biodiversity in contributing to soil condition. This research includes a Defra-funded review of the current available UK-affiliated evidence base. The Report of the review was published in March and has been placed in the House Library.

We are looking closely at its findings, including whether there is a need to carry out analysis of trends in biodiversity in order to understand better how the functions it supports, such as soil structure, water movement, nutrient dynamics and plant growth, contribute to soil condition across a range of ecosystem services and management practices.

Defra has not carried out any surveys of earthworm populations and diversity specifically in arable soils.

However, Defra carries out research on earthworms as part of a wider programme of research on sustainable land management because of their important role in developing soil structure, water movement, nutrient dynamics, and plant growth.

Defra has contributed funding to the Open Air Laboratory (OPAL) Soil and Earthworm Survey in England launched in 2012. Two technical reports detailing the analysis of the first set of results of the Soil and Earthworm Survey are publicly available on the website of Imperial College London.

Defra’s delivery partner Natural England has previously funded the London Natural History Museum to survey earthworms in a number of semi-natural sites across England and Scotland, but also included sampling from 6 arable sites. This work was captured in a report published by Natural England in April 2014 entitled “Earthworms in England: distribution, abundance and habitat”. The report is available on Natural England’s website, reference NECR145.

In 2014 Defra funded the establishment of the Sustainable Intensification Research Platform (budget £4,111,184), supporting research into sustainable productive farming techniques, which includes current assessment of earthworm abundance under contrasting arable systems at the Allerton Project at Loddington.

Defra has not carried out any surveys of earthworm populations and diversity specifically in arable soils.

Defra carries out research on earthworms as part of a wider programme of research on sustainable land management because of their important role in developing soil structure, water movement, nutrient dynamics, and plant growth.

Defra has not carried out an assessment of the current health and status or trends of earthworm populations in English arable soils.

However, Defra is working closely with the research councils and is funding research to improve our understanding of the role of soil biodiversity in contributing to soil condition.

Defra has funded or contributed funding to eight research projects between 1997 and 2013 that have assessed earthworm populations and diversity; their role under different systems of land management; and the impacts of pesticides. Defra has also contributed funding to the Open Air Laboratory Soil and Earthworm Survey in England, launched in 2012.

Natural England has previously funded the London Natural History Museum to survey earthworms in a number of semi-natural sites across England and Scotland.

A further Natural England project is currently under way with the London Natural History Museum, which is gathering data from external research projects on earthworm distribution.

Natural England also published in 2012 a commissioned report on “Managing Soil Biota to Deliver Ecosystem Services”, which explored management techniques that benefit soil organisms, including earthworms.

Defra carries out research on earthworms as part of a wider programme of research on sustainable land management because of their important role in developing soil structure, water movement, nutrient dynamics, and plant growth. While they are not essential to all healthy soil systems their presence is usually an indicator of healthy soil.

Since 2010, the Natural Environment Research Council (NERC) has funded four research grants involving earth worms. Details of the grants are below and are also available on the NERC website at http://gotw.nerc.ac.uk.

The four applications are very different, however each sets out to inform on the impact of environmental change on the biodiversity and ecological function. The work does not explicitly inform on management for cultivation or pest control.

The Biotechnology and Biological Sciences Research Council (BBSRC) have supported three projects that each included some research into the roles of invertebrates - but not specifically earthworms - in soil processes.

NERC funded research involving earth worms

1. Lead Grant Reference: NE/F001274/1

Research Organisation: Cardiff University

Actual Start Date: 01/04/2008

Actual End Date: 31/03/2010

Project Title: Sequencing a Soil Sentinel (SeqaWorm)

2. Lead Grant Reference: NE/H009973/1

Research Organisation: Imperial College London

Actual Start Date: 01/07/2010

Actual End Date: 31/12/2013

Project Title: Distinguishing pollutant-induced stresses from spatial and temporal environmental heterogeneity - a metabolomic approach to stress ecology

3. Lead Grant Reference: NE/I026375/1

Research Organisation: Cardiff University

Actual Start Date: 01/03/2012

Actual End Date: 31/08/2015

Project Title: Stress in a hot place: Ecogenomics and phylogeography in a pantropical sentinel inhabiting multi-stressor volcanic soils

4. Lead Grant Reference: NE/K015338/1

Research Organisation: The Natural History Museum

Actual Start Date: 23/09/2013

Actual End Date: 22/09/2014

Project Title: Scaling and thresholds in earthworm abundance and diversity in grassland agricultural systems

BBSRC funded research involving roles of invertebrates in soil processes

1. Lead Grant Reference: BBS/E/C/00005740

Research Organisation: Rothamsted Research

Actual Start Date: 01/04/2008

Actual End Date: 31/03/2012

Project Title: Developing a systems-based modelling approach to understand and predict consequences of grassland soil managements for atmosphere and water environments

2. Lead Grant Reference: BBS/E/C/00004977

Research Organisation: Rothamsted Research

Actual Start Date: 01/04/2008

Actual End Date: 31/03/2012

Project Title: Mechanistic descriptions for organic matter turnover in planted soils

3. Lead Grant Reference: BBS/E/C/00005741

Research Organisation: Rothamsted Research

Actual Start Date: 01/04/2008

Actual End Date: 31/03/2012

Project Title: Understanding the role of the soil microbial and invertebrate communities in plant-soil interactions