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Sustainable farming - farm effluent

farm effluentIn a nutshell...

  • Wherever you have farm animals there will be effluent (faeces and urine).
  • Farm effluent carries the risk of diseases and can be spread this way.
  • Grazing stock will spread their effluent on the paddock, but it will be in highly concentrated areas.
  • Effluent collected in ponds or septic tanks has to be spread on the land, and this must be done correctly.
  • One cow produces as much effluent as 12 humans.
  • Many weed seeds pass through grazing stock and are spread via the effluent.
  • Regional councils are now encouraging spreading effluent on land, rather than relying on two-pond systems and barrier ditches.
  • Regional councils are now putting a limit (eg 150kg N/ha) on effluent levels applied.
  • Stock crossing waterways and grazing near them will also deposit effluent in the water.
  • Stock crossing the road will deposit effluent on the seal and cause damage.
  • Effluent is regularly released from stock trucks on to the highway, causing problems for road users.
  • Diseases that can be spread by dung and urine are salmonella and campylobacter for humans, and Johnes disease, campylobacter, salmonella, yersiniosis, coccidiosis, leptospirosis and drench resistance in internal parasites in livestock.
  • Effluent accumulates on stock wintering pads and standoff areas, and must be disposed of correctly.
  • Farm effluent has a value as a fertiliser, and it's important to make maximum use of this.
  • A group of 36 cows each day deposit the equivalent of 1kg of superphosphate, 1.9kg of urea and 2.3kg of potassium chloride on their grazing area.

How can you tell if you have a problem?

  • Untreated effluent leaking into waterways - obvious from the colour of the water at point of entry.
  • Effluent ponds that are not working - foul smells and dirty water overflowing from the second (oxidation) pond.  A crust on the top of the first pond is acceptable.
  • Overflowing septic tanks.
  • Foul smells near waterways.
  • Stock having to waterways in their grazing areas with no proper bridges.
  • Stock having to drink from streams, creeks and dams.
  • Excess effluent lying on the pasture from grazing stock or spreading.
  • Rich growth of weeds where effluent has been spread.
  • Bare areas of pasture where excess effluent has burned the plants.
  • Pitted seal on the road where stock are crossing.
  • Effluent on road slopes emptying out from trucks.

How can you tell if you're doing well?

  • All streams and waterways through the farm are clear and rich in life.
  • No foul smells near waterways.
  • Waterways fenced off to prevent stock drinking, or standing in the water to keep cool.
  • Bridges provided for stock to cross waterways.
  • No weeds where effluent has been spread.
  • No feed pads or loafing areas for stock near waterways.
  • Septic tanks regularly emptied.
  • In two-pond effluent systems or barrier ditches, the outflow from the oxidation pond should be clear.

What can you do to improve things?

  • Be aware of your responsibilities under the Resource Management Act (RMA).
  • Regularly check septic tanks and have a programme for cleaning them out (before they overflow).
  • Inform households with septic tanks about what not to put in them that will kill the bacterial fermentation.
  • When applying effluent, do not exceed your local Regional Council's recommendations for Nitrogen levels.
  • Have water quality checked regularly, especially for domestic use.
  • Build bridges for stock to cross waterways.
  • Fence off waterways and protect riparian strips.
  • Have an analysis of effluent to be applied as fertiliser, to make sure you are using it correctly.
  • Control weeds that may flourish where effluent has been spread.
  • Do not graze effluent treated paddocks immediately.  Allow rain and sun to kill any bacteria.
  • Do not apply effluent to pastures that are very short or very long.  Pastures 5-6cm long are ideal.
  • Avoid stock crossing sealed roads - or place a mat on the surface for stock to walk on.
  • Empty out stock for 4-6 hours before transport.

Where can you go for help?

  • Regional Councils
  • County Councils
  • Federated Farmers of NZ
  • Ministry of Agriculture and Forestry
  • Department of Conservation
  • National Institute of Water and Atmospheric Research


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