CaSTCo (Catchment Systems Thinking Cooperative)

Project Background

The Soil SmARt project is a key initiative within the larger collaborative Ofwat funded project known as Catchment Systems Thinking Cooperative (CaSTCo). This nationwide project aims to establish national guidelines for citizen science monitoring. The Soil SmARt project focuses on both the Western Rother and Arun River catchments, with an emphasis on soil health, recognising the crucial connection between soil quality and the preservation of river quality.

The Arun and Rother Rivers Trust (ARRT) and Southern Water are working in close partnership under CaSTCo to deliver a soil health monitoring project, designed to test citizen science methods and link citizen science with professional fieldwork monitoring. This allows us to compare data collected in the field with data collected by an agronomist and analysed in a lab. We would like to work with farmers in the area to co-design a citizen science monitoring programme which empowers you to test your soils through simple but effective in-field methods.

S Woodley Crop Services set out to provide an industry level baseline to help understand the condition of the soils within the River Arun & River Rother catchments. The focus has been soil health, so there was an enhanced emphasis on biological indicators supported by laboratory-based analysis.

This data set will form part of wider project looking at comparing citizen science, industry standard and higher level (university) based field work.

Soil Sampling Parameters:

Measuring soil health is not a straightforward process and there is much debate within the industry on the parameters that should be measured. As always, there is a balance between gathering meaningful and practically useful data and just gathering data for the sake of it. Soil Sampling and field assessments where carried out between September and October 2024.

Through discussion with the farmers and associated industry partners in this project, it was agreed there should be a focus on the biological side of soil as an indicator of soil health. For example, Organic Matter and Earthworm Counts.

The starting point for the design of this project was understanding soil type variability within each field chosen by the host farm. We utilised EC (Electro Conductivity) Scanning via a Veris U3 scanner to help map soil type variability. This device pushes an electrical current through the soil via metal discs and measures the resistance levels. This changes depending on the sand, silt and clay content providing a soil type variability map. Please see example below:

Management zones of similar soil types are grouped together which then determines the areas for soil sampling (e.g. the coarse texture areas are grouped together).

Twenty-five soil cores were taken within each “management zone”, being logged via GPS for any repeated measurements needed in the future. Samples were taken down to 30cm to maximise the value of the associated carbon stock figures for any future carbon calculations. These samples were then aggregated together to form a separate sample for analysis from each zone.

Soil properties measured include:

· Macro Nutrients: P, K, Mg, Soil pH

· Soil Texture (Sand, Silt, Clay %)

· Bulk Density

· Organic Matter via Dumas

· CO2 Soil Respiration (Solvita Test)

· Earthworm Counts (3 per field)

· VESS (Visual Evaluation of Soil Structure)

To find out more about the CaSTCo partnership, hover over the images below and follow the links:

Working with: