Friday, 14 June 2024 07:55

Don't apply effluent to saturated soils

Written by  Staff Reporters
Any effluent applied to saturated soils is likely to pond and run off or leach through the soil or into tile drains, rather than being absorbed by the plants. Any effluent applied to saturated soils is likely to pond and run off or leach through the soil or into tile drains, rather than being absorbed by the plants.

Applying effluent to saturated soils is prohibited, and if a farmer is found to be in breach of this rule, they could face enforcement action.

When the soil is saturated, the pores within it (gaps between soil particles) are filled with water.

Any effluent applied during these conditions is likely to pond and run off or leach through the soil or into tile drains, rather than being absorbed and taken up by the plants.

So, how do you know if the soil is saturated? A simple squelch test can tell you, according to Otago Regional Council.

  • Step on the soil. If your boot mark fills with water, the soil is saturated.
    • Check your council website to see if you have a monitoring site nearby.
      • A hand-held moisture meter is useful. However, you need to test it in the soil in a range of conditions (dry– wet) so you see what reading to use for saturation.

Ponding occurs when the effluent, solids, and liquids that are applied to land stay on the surface as a pond or puddle rather than being rapidly absorbed into the soil.

Ponding of effluent results in runoff and leaching into waterways and groundwater aquifers and is a prohibited activity in the Otago Water Plan.

What causes ponding?

  • Too much effluent is applied to land, or it is applied too quickly for the soil to absorb it.
  • Effluent being applied when the soil is saturated.

Once the soil is squelchy under foot or at saturation point, it’s too late to avoid ponding and runoff. Irrigate only when there is enough soil water deficit to absorb the applied effluent.

If ponding or runoff occurs when there is a soil water deficit, it means you are applying too much effluent or applying it too quickly.

Applying solids, sludge, muck and slurry to paddocks must be treated the same as liquid effluent.

The same goes for effluent being applied with irrigation water, no matter what the mix is.

Good practices include timing: Do not apply sludge, muck and slurry solids to soils that are at or near saturation. Apply it to land when the grass or crops are able to take it up quickly and use it when soil moisture levels are low, and soil temperatures are warmer. Keep the application well away (at least 50 metres) from waterways.

Apply it as thinly and as evenly as possible. Do not dump large piles of muck onto paddocks. This creates a concentrated patch of effluent, or ponding, which is prohibited.

More like this

Sustainability remains a focus

A major focus for Fieldays in recent years has involved responding to the agricultural sector’s pressing challenges of environmental sustainability, climate mitigation and food production.

Freshwater crayfish still around

The presence of koura (freshwater crayfish) in the Kakahu River, South Canterbury, was one of the highlights of eDNA monitoring and biomonitoring (periphyton, macroinvertebrates and fish) carried out in the Kakahu River in March 2024.

Get the odour in order

Odour from farm dairy effluent is increasingly an issue as herd sizes grow and urban boundaries get closer to operating farms.

'Stand stock' before Moving Day

Southern dairy farmers are being reminded to undertake best practices to safeguard water quality and transport safety when the annual stock Moving Day begins shortly.

Featured

Red tape 'blocking access to crop production products'

Outgoing chief executive of Horticulture New Zealand, Nadine Tunley has taken a swipe at government agencies for the “costly and lengthy regulatory approval process” to get new crop protection products registered.

Farmers back ACT MP's bill

ACT MP and Northland dairy farmer Mark Cameron is lodging a new member’s bill that would prevent regional and district councils from regulating greenhouse gas emissions.

National

Cream of the crop

One of New Zealand's largest dairy farmers won the 2024 'Food, Beverage and Fibre Producer' award at the NZ Primary…

Machinery & Products

Revamped automatic calf feeder

JFC Agri, the family-owned manufacturer of agricultural products from Galway, Ireland, used Fieldays to launch its innovative Evolution range of…

ErgoPOD set for 2025 farm debut

Waikato Milking Systems has unveiled the final production version of its ErgoPOD, a state-of-the-art semi-robotic technology designed to increase milking…

» Latest Print Issues Online

Milking It

100-year-old milk powder

OPINION: A 100-year-old sample of milk powder from Ernest Shackletons’ first solo expedition to Antarctica has been analysed by scientists.

Farmer feedback

OPINION: Sticking with the NZ Primary Industries Summit, Fonterra chief executive Miles Hurrell’s quip about the milk price has been…

» Connect with Dairy News

» eNewsletter

Subscribe to our weekly newsletter