Project Summary NT1041 Phosphorus Losses from a Lowland Dairy Farm Robin Hodgkinson Robin'Hodgkinson

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Project Summary NT1041Phosphorus Losses from
a Lowland Dairy FarmRobin Hodgkinson
(Robin.Hodgkinson_at_adas.co.uk) Start
date 1/10/98. End date 31/3/02..

• Aims
• To measure phosphorus (P) losses and forms
  in subsurface flow from land used
  for lowland dairy farming

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Main messages

• Where rainfall occurred soon after cattle slurry
  application, when the soils were at or close to
  field capacity, drainflow P losses and
  concentrations were elevated (TP concentrations
  of up to 79mg P/l were measured )
• There were no appreciable increases in drainflow
  P losses where there was no drainflow within c.10
  days of application
• It is important to ensure that drainflow does not
  occur within a week of slurry application e.g. by
  applying slurry when there is a soil moisture
  deficit, when the medium- term weather forecast
  predicts no rain

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Co-ordination opportunities

• The P loss data will be useful for the
  development and validation of P loss models (e.g.
  PSYCHIC) following manure application to land.
• There are strong links with other groups in the
  Phosphorus Programme developing sustainable
  manure and nutrient management practices to
  minimise P losses from agriculture
• Research priorities for the future
• To better understand the processes and pathways
  of P loss following slurry applications to
  drained grassland and tillage soils, under
  contrasting soil moisture deficits.