Managing Soil Organic Matter – Development of Farm Advice
This note describes a 2 year Defra funded project which aims to develop advice for farmers to encourage sustainable management of Soil Organic Matter (SOM).
- What is Soil Organic Matter, and Why is it Important?
- Project Details
- Research to Develop SOM Advice
- References / Further Information
- Contact
What is Soil Organic Matter, and why is it important?
Soil Organic Matter (SOM) is any non-living organic material in the soil which is derived from organisms. Made from dead plant, animal or microbial material, or from dung and excreted materials, it is a complex mix of different substances. Some parts of it decompose rapidly, while much may remain unchanged in the soil for hundreds of years. Agricultural sources of SOM can include farmyard manure, slurry, crop residues, ploughed-in grass leys, green manures, bio-solids, compost and other organic waste material. In the cold, wet uplands, the decay of plant material is often so slow that the SOM forms on the surface as peat or as a peaty surface layer.
SOM is important for maintaining soil structure. It promotes a “crumb” structure (soil aggregates), improving both infiltration of water and water holding capacity. It can also trap nutrients in the soil for longer, and release them more gradually. It can make the soil more workable, needing less effort in preparing seedbeds. These properties of SOM can be managed agriculturally to help reduce diffuse pollution, and therefore contribute to the aims of the England Catchment Sensitive Farming Delivery Initiative (ECSFDI).
A recent study has also shown that, in almost all cases, more sustainable management of organic matter is likely to result in an increase in net farm profits.
SOM can lock away carbon, which might otherwise be released as greenhouse carbon dioxide. While this is most important in upland peatlands, more sustainable organic matter management in lowland farms can help lower greenhouse gas emissions by reducing use of inorganic fertilizers and fossil fuels. Organic matter is also the fuel that drives soil ecosystems, and increased inputs can result in greater biomass of soil organisms. This may help to ensure food availability for nesting birds in the farmed environment.
However, recent research indicates that SOM may be in decline across almost all soils types. While some of this decline may relate to climate change, the loss of SOM may be halted or reversed through agricultural management.
Project Details
The project aims to:
- describe the economic effects on farm businesses of applying SOM management techniques based on information from farmers.
- develop and pilot a system of SOM management advice to farmers, including advice on measuring the impact of their management practices on SOM.
- monitor farmers’ attitudes and activities relating to SOM management practices.
- show whether an existing SOM indicator can be used to predict the impact of changes in SOM management on SOM in high-risk catchments.
To achieve these objectives, the project includes a socio-economic and soil science research project, which is being undertaken by GY Associates in collaboration with Rothamstead Research . Further details of this are given in the section below on “research to develop advice”.
The project is concentrating on eight of the 40 priority catchments covered by the ECSFDI. These catchments have been identified by their soil types as being at particular risk of accelerated loss of SOM The catchments are:
- Wensum
- Exe
- West Peak District Dales
- Bassenthwaite Lake
- Eden
- Test
- Itchen
- Lugg
Maps of the catchments can be found on MAGIC . However, it is hoped that the advice generated and lessons learnt will be useful in all the catchments covered by the ECSFDI programme, and in the wider countryside.
Research to Support SOM Advice
GY Associates have agreed to pilot a system of advice which aims to influence farmers to change their management of SOM by providing them with information on the likely economic effects of such a change. They intend to use typified “case studies” which illustrate the economic effects of SOM management, and which are derived from the experiences of farmers interviewed during this and previous related projects. They also aim to conduct more extensive testing of Active C - an indicator of the proportion of soil carbon which takes ~2-5 years to decompose.
Their research activities will involve:
- Working with ECSFDI Catchment Sensitive Farming Officers to identify farmers which have made changes to their SOM management, and are interested in contributing to case studies.
- Offering farmers in the 8 priority catchments SOM advice sessions, based on the case study information.
- Recording how the advice provided affects farmers’ knowledge, attitudes and practices.
- Offering farmers the opportunity to test their soils for Active C, to determine the effect of their SOM management.
Contact
If you would like to find out more about the project, discuss an existing project to manage Soil Organic Matter or get involved with GY Associate’s research, please contact:
Matthew Shepherd – SOM Project Manager
Natural England
Estuary House, Peninsula Park,
Rydon Lane, Exeter, EX2 7XE
Tel: 01392 352053 E-mail: matthew.j.shepherd@defra.gsi.gov.uk
References / Further information
ADAS (2003). Development of economically and environmentally sustainable methods of carbon sequestration in agricultural soils. Final Project Report, Defra Project SP 0523, Department for Environment Food and Rural Affairs.
Bellamy PH, Loveland PJ, Bradley RI, Lark RM, Kird GJD (2005).Carbon losses from all soils across England and Wales 1978-2003. Nature, 437:8 pp. 245-248
NSRI (2006). Soil Organic Matter as a headline indicator of soil health. Report to Defra, SP 0546 (draft). National Soil Resources Institute, Cranfield University, Bedfordshire.
Rothamstead Research (2004). To develop a robust indicator of soil organic matter status. Final Project Report, Defra Project SP 0310, Department for Environment Food and Rural Affairs.
Page last modified:
31 October 2006
Page published 31 October 2006