The co-author of the study is Professor Andrew Whiteley from the Centre for Ecology & Hydrology (CEH) in Wallingford, UK. He said, 'People take the billions of microbes under foot for granted, but the bacteria are critical to soil fertility and quality, and play a key role in cycling greenhouse gases. In this study we have pulled back the earth's skin to reveal how and why bacteria in the soil vary across the landscape.'
Part of the nationwide Countryside Survey, the research took four years to complete between 2007 and 2011. Far from being randomly distributed in soil these bacterial communities or biomes are organised according to their associated plant communities above. Their composition also reflects the pH of the soil.Over 10,000 species of bacteria in each gramme of soil are inextricably linked to its fertility and underlying quality, as the communities of micro organisms are responsible for processes critical to plant growth and crop productivity such as nutrient cycling, and decomposition, the recycling of decaying plant matter such as autumn leaves or wheat straw. Plants simply cannot grow in sterile soil, soil without microbes.
Teams from the CEH, Newcastle and Oxford Universities analysed the microbial DNA from over 1,000 soil cores from around the country. The soil samples and DNA used in the study have been frozen as a future resource that provides a snapshot in time of the biological characteristics of Britain's soils and greatly improves our knowledge of the biodiversity of bacteria in our soils, their distribution and function.
With farmers being urged to produce ever greater yields to feed a burgeoning population the more we understand about the nature of soil quality, the better.
Geoforensic scientist, Lorna Dawson of the James Hutton Institute also added, 'Soil DNA data like this could also help forensic scientists reference samples of soil in evidence and also to locate the scene of a crime or a buried body.'
Previously science had assumed that microbes were randomly and evenly distributed throughout soils. The team's results are published in the scientific journal Environmental Microbiology on April 20th 2011.
Image Credit: CEH. Green fluorescent bacteria on a crumb of soil.