Dual purpose varieties offer value adding opportunities
Dual-purpose crop varieties have significant potential to increase the cropping options and profitability of enterprises in the northern grains region.
Recent studies supported by the Grains Research and Development Corporation (GRDC) have found key opportunities exist to expand the use of dual-purpose crops in northern mixed grain-livestock areas, particularly with long-season cereal varieties or grazing early-sown short-season varieties to delay phenology to ensure flowering remains in the appropriate window.
Dual-purpose crop varieties are not regularly sown in northern crop-livestock regions such as northern New South Wales and southern Queensland. However, a number of advantages exist in increasing their use according to CSIRO Farming Systems Research Scientist Dr Lindsay Bell.
“Longer season dual-purpose crops could provide early sowing options to spread farming operations over the autumn period and spread risk associated with crop establishment and frost,” Dr Bell said.
“Grazing of either long-season or typical shorter-season crops could be used for canopy management to slow early season crop water use and ensure more water is available for the vital grain-filling period.
“In seasons with dry spring conditions we have found this conservation of water allows crops to achieve similar grain yields to ungrazed crops.
“Forage-only crops such as oats could be replaced or complimented to provide feed between June and August when pasture growth and quality is often low. This would also reduce grazing pressure on the pasture component of the system helping to improve their overall persistence and health.”
Research has identified that early-sowing opportunities from February to April occur frequently in the northern region, which would allow grazing from the end of May to early August with up to 2000 sheep-grazing days per hectare possible under best management practice in favourable seasons.
Dual-purpose cereal trials conducted by the NSW Department of Primary Industries (DPI) at two trial sites in northern NSW between 2008 and 2012 concluded that oats and barley produced more dry matter than wheat and triticale across a range of seasons, and that triticale produced the highest grain yield following grazing.
Conducted as part of the GRDC-funded National Variety Trials, the research evaluated a range of wheat, oat, barley, triticale and cereal rye varieties, both commercial and experimental lines, totalling 127 different entries over the five-year period.
The research found that no one variety excelled in terms of ranking in the top 10 for dry matter production and grain yield, although Urambie barley proved the best overall performer followed by El Alamein and Endeavour triticale and the winter wheat Tennant.
One of the major recommendations from the research trials was that selection of dual-purpose varieties should always be based on individual enterprise needs and the priority end use for each paddock.
One of the researchers, Leader Northern Dryland Cropping Systems with the NSW Department of Primary Industries (NSW DPI), Loretta Serafin, said managing the timing and intensity of grazing dual purpose cereals was critical to achieving maximum dry matter and grain yield recovery and careful consideration needed to be given to the growth rate of individual varieties.
She said grazing could commence once plants were adequately anchored with secondary roots to prevent stock from removing plants from the ground.
“Identifying when to stop grazing is a critical component in maximising dry matter and grain yield outcomes. Once a variety reaches Zadok’s growth stage 30 it is changing from vegetative to reproductive phase. Beyond this stage nodes may be felt inside the stem of the plant indicating that the developing head has now moved above ground level,” Ms Serafin said.
“At this stage livestock should be removed and the paddock locked up for grain recovery or hay production.
“If livestock are allowed to continue grazing beyond this point, developing heads may be grazed off leading to significant reductions in grain yield and tiller death. Growth stage assessment should always be carried out on the primary tiller as it is the most advanced.”
The time taken to reach growth stage 30 varies with variety, temperature and grazing intensity, as well as several other factors according to Ms Serafin.
“In all situations it is recommended to split the variety selection and sowing time of dual-purpose cereals where possible. This will spread the period when grazing can occur and also the risk of crop failure due to dry conditions or disease,” she said.
A dual-use crops survey conducted by the GRDC in 2011 found that the major factor limiting growers’ use of dual-purpose crops was a fear that grain yield would be sacrificed.
The GRDC is currently investing in research aimed at quantifying this and to provide recommendations on how grain yield recovery can be maximised after grazing.
For more information on research into dual-purpose crops in the northern region, visit www.grdc.com.au/Research-and-Development/GRDC-Update-Papers/2013/02/Dual-Purpose-Cereals-Varieties-and-Management-for-the-Northern-Slopes-and-Plains
A GRDC factsheet on utilising dual purpose varieties to bolster feed supply and improve profitability and sustainability is available at www.grdc.com.au/uploads/documents/GRDC_Dual-PurposeCrops.pdf
Dr Lindsay Bell, CSIRO Farming Systems Research Scientist
07 4688 1221
Loretta Serafin, Leader Northern Dryland Cropping Systems, NSW Department of Primary Industries
02 6763 1147, 0427 311 819
Sarah Jeffrey, Senior Consultant Cox Inall Communications
GRDC Project Code DAN00135; GRD4-6; DAQ00162