Good-looking grass
A pasture management tool that might not give a pretty outlook to start with, will produce stunning results in the end. By Sonita Chandar.
Ateam of scientists at Agresearch who have been working with livestock farmers trialling deferred grazing on their farms, say the results have been positive.
Agresearch senior scientist Katherine Tozer said 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,” Tozer said.
As evidence grows that deferred grazing can improve pasture quality and potentially resilience in a changing climate, farmers are being encouraged to try it.
Deferred grazing, the practice of dropping paddocks out of the rotation from mid-spring until late summer/early autumn, optimises grazing pressure on the remaining paddocks and maintains or improves pasture quality.
The practice can also be beneficial in providing a feed wedge at the end of summer, increasing both pasture persistence and clover populations.
The study in recent years was to gauge the value of deferred grazing. On one summer-dry beef and sheep hill country farm in Waikato, it was estimated that deferred grazing on 15% of the farm increased total farm and per-hectare gross margins by 8%, according to FARMAX modelling.
In a completed project with farmers
Bay of Plenty sheep and beef farmer Rick Burke said ‘deferred grazing might look ugly before grazing’, but it brought financial gains.
and other partners, Agresearch scientists compared deferred grazing with traditional rotational grazing in a field plot and splitpaddock trials on three North Island sheep and beef hill country farms.
The study showed that 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 were reduced.
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.
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 said new funding from the government and industry – through the Sustainable Food and Fibre Futures fund – would test whether extended periods of deferred grazing encouraged pasture roots to grow larger 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 for Primary Industries, Beef + Lamb New Zealand, Dairynz, Ballance Agrinutrients and others to run a series of field days on farms over coming weeks to show farmers what the opportunities are.
Tozer said it was exciting to move to a new phase of the research that would look at the opportunities from deferred grazing for root mass and depth, soil carbon sequestration and for reduced environmental impacts such as greenhouse gas emissions, nitrogen leaching. and phosphorus and sediment loss.
“The most exciting aspect for us is that we are working in a true partnership with farmers, the industry bodies and the government. It means what we learn from the research can be quickly and efficiently passed to farmers to put into practice, and that is very rewarding for us working on the science.”■
More on the practice of deferred grazing can be found at: https://www.agresearch. co.nz/our-research/deferred-grazing/