Sharing benefits of deferred grazing

Scientists at AgResearch have been working with livestock farmers in recent years to gauge the value of the practice whereby paddocks are dropped out of the rotation from mid-spring until late summer/early autumn to optimise grazing pressure on the remaining paddocks and maintain or improve pasture quality. On one summer dry beef and sheep hill country farm in Waikato, it was estimated that deferred grazing on 15 per cent of the farm increased total farm and per-hectare gross margins by 8 per cent, according to FARMAX modelling.

The positive response from farmers who had trialled deferred grazing and become converts over the years has led to further research being committed to. In June, Agriculture Minister Damien O’Connor announced that new funding from the government and industry — through the Sustainable Food and Fibre Futures fund — would test whether extended periods of deferred grazing encourages pasture roots to grow large and deeper. In theory, this would increase water and nutrient use efficiency, reduce nutrient losses and increase pasture resilience to recover from extremities in the weather, the Minister said.

AgResearch is now joining with the Ministry of Primary Industries, Beef + Lamb New Zealand, DairyNZ, Ballance Agri-Nutrients and others to run a series of field days on farms over the coming weeks to show farmers what the opportunities are.

AgResearch senior scientist Katherine Tozer says deferred grazing was a management tool that was a low risk and cheap option to rejuvenate pastures.

“The feedback we have had from farmers we have worked with, and the results we have seen on their farms, has been really encouraging,” Dr Tozer says.

Bay of Plenty sheep and beef farmer Rick Burke said his experience was that “deferred grazing might look ugly before grazing, but the result is outstanding” and brought financial gains; while farmer Allen Coster said deferred grazing had become a “vital and proven management practice” in his farming operation.

In a completed project with farmers and other partners, AgResearch scientists compared deferred grazing to traditional rotational grazing in a field plot and split-paddock trials on three North Island sheep and beef hill country farms.

Compared to standard rotational grazing, deferred grazing improved pasture performance by increasing the pasture quality at the farm scale, increased pasture production, ryegrass ground cover and tiller densities, and increased topsoil moisture at the summer dry site. The weed content and facial eczema spore count in the pasture was reduced.