Phil Cranney – Senior Land Services Officer, Pastures
Spring and summer grazing management in above average rainfall years
The “spring flush” is here. Very few farmers have seen the elusive “spring flush” since 2016, but we are all grateful is has decided to show up in 2020. While the 2-metre-high roadside green feed in some areas may indicate to city dwellers that we are having a decent season west of the sandstone curtain, there is always more to it than meets the otherwise untrained eye.
The top five factors influencing the spring flush are:
- Soil depth, moisture, texture and fertility
- Aspect, altitude and topography
- Pasture – grass/herb/legume, annual/perennial, Cool (C3)/Warm(C4) season, growth habit and growth stages
- Overall grazing pressure
- Grazing strategy/management
So, how do we best utilise this “spring flush”?
For farmers that have a feed surplus, here are some options to consider:
- Make silage and store in underground pits – a recent series of 6 on-farm field days, the consensus was that silage could be made & stored in pits for approx. $100-150/tonne dry matter
- Make hay – hay and silage can improve climate risk management, and clean up weeds
- Spray graze technique to reduce nuisance annual grasses such as barley grass. N.B. This strategy would be restricted to high altitude areas in mid-late spring as an option
- Brown manure weedy paddocks – spray out to stop weed seed set and conserve moisture
- Green manure – while costly, this may be an option for acidic paddocks where lime can be incorporated to depth. N.B. Sodic soils should not be cultivated, due to the erosion risk
- Harvest pasture grasses for own use – select very weed free paddocks
- Spell the native grass hilly paddocks on fragile soils – a mulch layer would protect the soil, also allows beneficial native grasses to seed and increase recruitment potential
- Spread out your livestock so that you can achieve the highest potential individual animal weight gain, as the EverGraze grazing management experiment at Panuara demonstrated
Ditching your grazing rotation in favour of a continuous grazing management strategy for a few months in late winter, spring, and early summer, will not ruin your pasture. If you have minimum pasture benchmarks and a de-stocking strategy, ground cover can be maintained while maximising animal production.
The key thing to remember is that C3 cool season pastures are all in stage III growth stage, in which, even at very high grazing pressure, very minimal damage can be inflicted to the plant. However, be sure to rest aerial seeding types, such as serradella and arrowleaf, balansa, gland and bladder clovers to boost the seed bank for the coming years.
Common grazing management mistakes in spring and early summer include:
- Resting paddocks with high risk perennial weeds – sometimes perennial weeds flourish in long rest period grazing management situations, e.g. St John’s Wort, and winter grasses can hide the new shoots of silver-leaf and sticky nightshades
- Not utilising the pasture in paddocks with limited dam water storage before it gets too hot
- Unnecessary consolidation of livestock mobs that can reduce individual animal performance, increase stress, and put more pressure on water infrastructure
- Not seizing the opportunity to rest weed free hilly native paddocks with fragile soils
- Inflexible grazing management rotation that could see pasture quality and individual animal production decrease rapidly
It is often tempting to over-complicate grazing management in the pursuit of perfection, but if we stick to the simple ethos of matching feed demand with feed supply, then very little can go wrong.
If you have any questions about grazing management, contact your local agronomist or our Pasture and Livestock Officers.