What was the problem?

Grazing a crop has risk to grain production, but careful grazing can minimise yield risk. This trial was to further explore safe grazing crop practices and management strategies.

The aim was:

To validate the effect of grazing intensity and growth stage on forage value and yield response of different wheat varieties, with sowing times suited to cultivar.

What did the research involve?

• Replicated field trial was sown using a split plot trial design with time of sowing as main plots and variety x grazing as sub-plots
• Rosella and Revenue were sown on 1 April. Received 50 mm of rain during March, with 10 mm falling just prior to sowing. Harvest date 14 November.
• Scout and Mace were sown on 6 May. Sowing occurred after 30 mm of rain during April, with 13 mm falling just prior to sowing. Harvest date 1 December.
• All plots established very evenly.
• 30cm row spacing

What were the key findings?

Early grazing of crops occurred at GS16 when plants were 25- 35 cm. Late grazing occurred when plants were at GS30-32 when crops were 40-45 cm tall.

Feed value of Rosella and Scout wheat grazed at different times and intensities, Quambatook 2014

Rosella

• Grain yields unaffected, but yields poor
• Grain protein higher for ungrazed and early-light grazed, but all protein levels high, greater than 14%
• Screenings not affected

Scout

• Didn’t produce as much DM as Rosella
• Yields of heavily later grazed crops were lower
• Grain protein unaffected
• Screenings 5% higher

Final comment

• Grazing crops early and/or lightly will generally not affect grain yields.
• Plant recovery is supported by having more green material remaining after grazing; the more the merrier!
• Early sown winter wheat can produce more biomass earlier in the season than spring wheat varieties.