Hampshire Avon
Demonstration Test Catchment (DTC) Project

Hampshire Avon Demonstration Test Catchment (DTC) Project
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Soil drainage monitoring

The experimental design will involve comparing control and manipulated clusters of fields on target farms.
The soil drainage monitoring will comprise:

Soil Mineral Nitrogen (SMN) sampling


 SMN sampling using a Hydrocare

Soil Mineral Nitrogen (SMN) is a useful measure of the nitrogen available to the crop and potentially at risk from leaching loss, and is commonly measured on experiments testing crop response to nitrogenous fertiliser or organic manure.

Soil samples for SMN are taken to 90cm depth in 3 increments of 30cm (0-30cm, 30-60cm, 60-90cm).

Samples are taken across a field using a standard ‘W’ shape and bulked together for each depth to give a representative sample for the field.

SMN samples will be taken in our target fields (please see table below for distribution of fields across the target sub-catchments).  Samples will be taken at field capacity in the autumn and the spring.

The table below shows the distribution of our target fields:


 Target sub-catchment  Control/Manipulated/EA WPZ project   Number of fields
 Upstream of Kingston Deverill, River Wylye  Control sub-catchment 


 Between Kingston Deverill and Brixton Deverill, River Wylye  Manipulated sub-catchment 


 Upstream of Ebbesbourne Wake, River Ebble  Manipulated sub-catchment 


 Cholderton borehole catch zone  EA WPZ project 


The Avon DTC has aligned with the regional and local EA through the Cholderton borehole Water Protection Zone (WPZ) project for this monitoring work.  Sampling is occurring on both grass and arable fields and results will enable empirical data to be linked to modelled information for borehole water quality at Cholderton.

For more information on SMN sampling and the work being undertaken to help understand the groundwater pathways please see the following factsheets:

SMN Sampling

BGS Hydrogeological conceptual modelling