Soil erosion issues laid bare at Anglia Ruskin
Published: 19 February 2015 at 11:51
Dr Evans to deliver talk as part of Global Sustainability Institute’s Seminar Series
Soil expert Dr Bob Evans will discuss the problem of erosion – and the steps that can be taken to prevent it – during a free public talk at Anglia Ruskin University in Cambridge.
Dr Evans is a member of Anglia Ruskin’s Global Sustainability Institute (GSI) and has been studying the soils and erosion in Britain since the late 1960s, especially in Cambridgeshire and Eastern England, including the famous Fen Blow.
During the GSI Seminar Series talk on Wednesday, 25 February, he will cover the causes and effects of the main types of erosion in Britain, as well as set out his proposals to tackle the problem.
Dr Evans said:
“Soil is precious stuff – it grows our food, fibre, fuel and timber – so it’s no surprise that the United Nations declared 2015 International Year of Soils."
“Mineral soil formation is extremely slow and any loss is best considered irreplaceable. Organic matter can form quickly but can disappear equally quickly, and erosion is probably more widespread now than it has been for hundreds of years.”
Disturbance by animals is a major cause of soil erosion in upland areas of Britain. In the lowlands such as the East of England, the damage is mainly done by wind and water erosion.
Dr Evans added:
“Wind erosion affects cultivated peaty and sandy soils, and one of the most famous examples is the Fen Blow in Cambridgeshire. This became more of an issue in the 1960s as fields were expanded and trees along field boundaries were removed.
“Farmers are certainly aware of wind erosion as they can see money blowing away. Blows remove seedlings, often of high value crops such as sugar beet and vegetables. Because of this they make efforts to control it, for example planting protective ‘nurse crops’.
“Water erosion of arable land occurs widely but is more extensive and severe where soils have high sand and silt contents and are freely draining. Some crops have been known for a long time to be at risk of erosion, sugar beet and potatoes for example, but water erosion only became high on the agenda when autumn-sown cereals became the dominant crop.
“Autumn-sown cereals out yield spring-sown cereals and so farmers put more land under winter cereals. Soils are wetter in winter and runoff from the land causes flooding of roads and property.
“Since the 1960s field boundaries have been removed and machines have got bigger so compacting the soils, both factors encouraging erosion and runoff. Also outdoor pig-rearing has become widespread in the last 20 years, usually on sandy soils such as in Norfolk and Suffolk, causing widespread muddy floods.”
Dr Evans has set out five key proposals to tackle soil erosion in the lowlands and the issues surrounding it, although he acknowledges that current farming economics mean it is unlikely these will be implemented:
- Smaller fields, so more boundaries – grass, shrubs and trees – and more ditches. This will reduce the likelihood of wind and water erosion, as well as increase biodiversity.
- Smaller and more fuel efficient equipment – tractors, drills, harvesters – leading to better timeliness in working the land, less soil compaction, less runoff and erosion, and hence less flooding of property and roads, and pollution of water courses.
- Fewer and more precisely applied inputs, eg fertilizers and pesticides, so less chance of polluting water courses. Also there will be less energy and petroleum used to produce the inputs.
- More integrated farming, combining both arable and pastoral land use, but not intensive livestock production that results in soil compaction. And better and longer rotations. Insert grass into the rotation where land is unsuited to cultivation, in the wetter parts of the country, or where it is vulnerable to runoff.
- Application of more manure/compost both from farms and towns, leading to better soil structure and more rapid infiltration of rainfall into soils and so less runoff.
Dr Evans’ free talk begins at 1pm on Wednesday, 25 February in room LAB 109 on Anglia Ruskin’s Cambridge campus. For further information, please email email@example.com