Over the years Loe Pool Forum has build a productive relationship with Neill Wood (Programme Director for MSc Surveying and Land/Environmental Management) at Camborne School of Mines (CSM). In 2017 Andrew Benny, CSM Masters student, conducted a research project to test new methods for assessing soil conditions.
This project focussed on agricultural land in the River Cober catchment and considered whether soil erosion was taking place within some of the arable fields in the north of the area.
The combined methods of surveying, geophysical techniques (non-invasive electromagnetic induction and resistivity tomography) and soil sampling were used extensively, with a particular aim of examining levels of available phosphorus in the soil.
It was found that significantly higher levels of available phosphorus were present in the arable fields compared with the pasture fields studied. The variations within the arable fields were categorised into three types according to the gradient of the land and whether the areas were likely to be stable, erosive or aggrading zones.
Significantly higher concentrations of available phosphorus were present in the stable zone compared with the steeply sloping (erosive) area. The low overall levels of available phosphorus that were found may have been the result of erosion but could also have been influenced by limited application of fertiliser.
The soil profiles provided a useful means of validating the findings from the geophysical techniques. Considerable deposited material was found at the lower elevation zones of the arable fields and this was also indicated by the resistivity images. This method also indicated that high clay content was present at depth, with possible implications for sub-surface water flow.
You can read the full Dissertation here; 2017 – The application of land surveying and geophysical techniques to the study of within-field variation of soil properties in the upper catchment of the River Cober.