A New Approach To Soil Sampling For Risk Assessment Of Nutrient Mobilisation.
Abstract
Traditionally, risks of nutrient and sediment losses from soils are assessed through a combination of field soil nutrient values on soil samples taken over the whole field and the proximity of the field to water courses. The field average nutrient concentration of the soil is used by farmers to determine fertiliser needs. These data are often used by scientists to assess the risk of nutrient losses to water course, though are not really `fit' for this purpose. The Eden Demonstration Test Catchment (http://www.edendtc.org.uk/) is a research project based in the River Eden catchment, NW UK, with the aim of cost effectively mitigating diffuse pollution from agriculture whilst maintaining agricultural productivity. Three instrumented focus catchments have been monitored since 2011, providing high resolution in-stream chemistry and ecological data, alongside some spatial data on soils, land use and nutrient inputs. An approach to mitigation was demonstrated in a small sub-catchment, where surface runoff was identified as the key drivers of nutrient losses, using a suite of runoff attenuation features. Other issues identified were management of hard- standings and soil compaction. A new approach for evaluating nutrient losses from soils is assessed in the Eden DTC project. The Sensitive Catchment Integrated Modelling and Prediction (SCIMAP) model is a risk-mapping framework designed to identify where in the landscape diffuse pollution is most likely to be originating (http://www.scimap.org.uk) and was used to look at the spatial pattern of erosion potential. The aim of this work was to assess if erosion potential identified through the model could be used to inform a new soil sampling strategy, to better assess risk of erosion and risk of transport of sediment-bound phosphorus. Soil samples were taken from areas with different erosion potential. The chemical analysis of these targeted samples are compared to those obtained using more traditional sampling approaches. Outputs from both approaches are used to produce risk maps, with the outputs and usefulness in the interpretation of observed in-stream dynamics evaluated. Potentially, this approach could better identify critical hotspots which can be incorporated into catchment management plans for the restoration and improvement of ecological status.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.H33J1695J
- Keywords:
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- 1804 Catchment;
- HYDROLOGYDE: 1843 Land/atmosphere interactions;
- HYDROLOGYDE: 1848 Monitoring networks;
- HYDROLOGYDE: 1855 Remote sensing;
- HYDROLOGY