High rainfall zone cropping and biodiversity.
Dual-purpose Cropping in the High Rainfall Zone
A new CSIRO project takes dual-purpose crops to the whole-farm level, increasing flexibility for farmers as climate conditions become more challenging and offering potential extra earnings of A$150m per year in New South Wales alone.
27 February 2012 | Updated 10 May 2012
Integrating dual-purpose crops
Dual-purpose crops can be grazed by livestock then produce a grain harvest. Farmers have been using dual-purpose cereals for years, to fill a winter feed gap and improve the profitability and flexibility of mixed farming
With Grains Research and Development Corporation (GRDC) funding, CSIRO’s Drs Hugh Dove and John Kirkegaard have been working on dual-purpose wheat and canola respectively, investigating the best management practices to minimise the effects of grazing on crop yield. Both found that timing of stock removal rather than stocking rate was the crucial factor to ensure good recovery and yield.
They joined forces to investigate the benefits of an integrated system that involves moving the animals from pastures to canola, to wheat, then back to pastures.
This system has the advantage of keeping animals off the pasture for longer, giving it a good chance to recover in late winter and provide more feed when the sheep return.
In the past, computer modelling has been used to determine how experimental results would apply on a larger scale. As part of the new project, researchers are collaborating with farmers to design whole-farm approaches that maximise flexibility to ensure the highest possible revenue even in increasingly challenging environmental conditions.
Dual-purpose crops have so far been assessed in the south-eastern Australia. The new project extends studies to Western Australia and Northern NSW.
This work is part of CSIRO's Sustainable Agriculture Flagship in collaboration with farmers, consultants and staff of the state Departments of Agriculture, with funding from the Grains Research and Development Corporation.
Results from the field trial (Canberra region) in 2010 showed that moving stock off pasture to graze canola first followed by wheat and back to pasture in late winter increased sheep grazing days by 30-47% over grazing grass pasture alone (see figure below). This practice offers potential benefits for growers including:
- improved availability of high energy forage in the colder winter months
- resting of grass pastures until spring, which maintains pasture growth during winter
- reduced crop bulk at harvest which makes canola windrowing easier and faster
- increased livestock profitability through increased winter stocking rate with little or no reduction in grain yield
- Evidence suggests the canola should be grazed first, as it recovers more slowly from grazing than wheat. Growers can commence grazing canola before moving stock to wheat and then finish winter grazing on rested pasture which also benefits from the reduced grazing while the stock graze the crops.
- A combination of canola, wheat and pasture with an effective rotation strategy is a proven way to reduce root and leaf diseases and control weeds in the HRZ. This can lead to better yields of cereals and better pasture establishment.
- Integrating canola or wheat offers flexibility to growers during the growing season. For example, winter grazing offers a potential source of income to offset crop establishment or additional livestock purchasing costs. If crops become droughted or frost affected, growers may decide to forego grain production and cut the crops for hay or silage after grazing. Even in times of severe drought, early grazing provides income when grain harvests fail.
On mixed farms, the profitability of the grazing enterprise is determined largely by the winter stocking rate. Dual-purpose crops accumulate more biomass and can carry more stock than pastures during these winter months and as mentioned above, grazing the crops allows pastures to recover, reducing the risk of costly supplementary feeding. Growers must plan for increased stock levels to capitalise on this opportunity.
Dual-purpose crops are also a risk management tool, securing income from dry matter when rainfall is good and providing flexibility to produce hay, silage or trade livestock on spelled pasture if the spring season is good.
Despite colder, drier conditions and later sowing in 2011 the benefits of the grazing crops to pasture spelling and growth were repeated. The benefit of the 2010 canola crop to the grazed wheat crop in 2011 through reduced disease and weeds increased the yield of wheat from 5 t/ha to 6 t/ha.
GRDC articles and presentations
Kirkegaard J, Dove H, Kelman W, Sprague S, Hamblin P. 2011. Integrating dual-purpose crops – capturing the whole-farm benefits [external link]. Invited contribution in GRDC-sponsored Grains Research technical Update, Ballarat, Victoria. February 9-10, 2011, eds Kathryn Toomey and Jane Crane (ORM Communications, Bendigo Vic.), pp 71-77.
Dove H, Kirkegaard J, Kelman W, Sprague S, Hamblin P. 2011. Integrating dual-purpose crops – capturing the whole-farm benefits. Invited contribution in GRDC-sponsored Grains Research technical Update, Young, NSW. February 15-16, 2011, eds Kathryn Toomey and Jane Crane (ORM Communications, Bendigo Vic.), pp 141-148.