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Brimstone III - leaching of pesticides to drainage water from a structured clay soil - PL0502

MAFF PSD are currently funding a programme of research in order to develop
farming practices that ensure the accurate delivery of pesticides to their targets. - additionally, such practices should reduce the movement of pesticides into
drainage water following application, and so maintain the quality of drinking-
water to the EC standards. The Brimstone experiment will address the problems
of pesticides appearing in drainage water from drained, cracking claw soils. Whilst
the amounts of compounds, such as the herbicide isoproturon, found in drainage
water has represented less than 1% of the applied dose in the experiments to date
at Brimstone, the concentrations found (typically 3 to 50 ug e-1 ) are many times
the permissible concentration of 0.1 ug e -1 laid down by the EC for drinking water

Subsequent dilution of drainage water and substantial degradation of the
pesticides therein does considerably reduce concentrations before such surface eater reach domestic supplies, but, especially in intensively farmed areas such as East Anglia, it has not always been possible for the water Companies to meet the standards laid down by the EC Directive.
1. By April 1994
Develop and test, on lysimeter and field samples, analytical methods for several pesticides of differing physico-chemical properties (eg mecoprop, chlorotoluron, isoproturon, prochloraz, pendimethalin) at sub parts per billion level in drainage water.

2. By April 1994
Take lysimeters of differing lengths (o.33 to 1.0m) from Brimstone, transport to Rothamsted and conduct initial leaching experiments to look at the processes of macropore flow of pesticides.

3. By April 1996
To understand the processes whereby pesticides appear in water flowing from drains and in water from the cultivated layer. Given the structured nature of the clay soil at Brimstone, which is typical of many cultivated areas in the UK, the emphasis will be on investigating in the field the process of flow via macropores such as cracks and wormholes.

4. By April 1997
To develop techniques of manipulating depth to the soil water-table and influencing the structure of clay soils so as to minimise losses of pesticides to drainflow.

5. By April 1997
To model the processes of movement and degradation of pesticides in soil, including if possible the movement via macropores to drainflow.
Project Documents
• Final Report : Brimstone III - leaching of pesticides to drainage water from a structured clay soil   (35k)
Time-Scale and Cost
From: 1993

To: 2000

Cost: £1,251,838
Contractor / Funded Organisations
Rothamsted Research (BBSRC)
Fields of Study
Pesticide Safety