EW urges careful management of flood-damaged pasture

Environment Waikato is urging Waikato farmers with flood-damaged pasture to seek expert advice to help paddocks recover and get grass growing again.

Many farmers around the Waikato have been left with paddocks under water following recent flooding in parts of the region.

The council’s sustainable agriculture coordinator Bala Tikkisetty said while speedy recovery of pasture was important, a rush job could have poor results.

Mr Tikkisetty said pastures under water for 2-3 days would probably recover, but prolonged flooding was likely to kill pasture and inhibit new growth because of a reduction in soil oxygen levels.

“Paddocks recently grazed before the flooding will be worst affected, as will pastures with at least 5cm of silt cover,” he said.

Mr Tikkisetty urged farmers not to try to kick start growth by heaping on fertiliser.

“Fertiliser is a major farm expense and when too much is applied it runs off into streams, rivers and lakes, causing algal growth and water quality issues,” he said.

“Consult with your fertiliser representative or farm consultant about testing your soil before applying fertiliser to make sure you’re only applying what your soil needs. Be aware of nitrate poisoning on lush new grass.”
Soils should also be carefully managed to prevent pugging and pasture damage, he said.

“Drainage of the whole profile is the first priority. Keep heavy animals, machinery and farm vehicles off soft, wet soils for as long as possible to prevent damage due to compaction and build pasture cover to provide physical protection against pugging.

“Pugging occurs when the soil is so soft that the weight of grazing animals cannot be supported by the soil surface. Allow time for soil and pasture to recover after the flood, especially by avoiding treading damage. Aerate the soil if possible by loosening it with a soil aerator.

“On-off grazing is the most effective method of minimising pugging and pasture damage. It involves having stock on pasture for short periods of time – often only four hours in very wet conditions. For the rest of the time the stock stand on purpose build stand-off pads or on the dairy farm yard. Feed supplements on the feed pad rather than on the paddock.”

Mr Tikkisetty said a sensible riparian management plan could prevent stream bank erosion, which may undermine fences and erode away productive land.

For more information about pasture management or environmental management, please call Mr Tikkisetty on 0800 800 401.