The effect of grazing intensity on crops

Birchip Cropping GRoup - Alison Frischke and Dannielle Ick

Type: Research Paper
Knowledge level: Advanced

Farm Table says:

Thinking about grazing wheat? Check out these results to avoid yield penalties.

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. Sowingoccurred 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 Source: EPARF
  • 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.
2015 - Birchip Cropping GRoup - Alison Frischke and Dannielle Ick
Read ArticleSave For Later

Related Resources