Autumn Forage and Pasture Options
By Adrian Smith, Senior Land Services Officer - Mixed Farming Systems
We are quickly approaching that time when producers will be considering their autumn and winter grazing programs.
Each grower’s decision will be different depending upon their situation, but given the autumn will set up your winter (and then spring) feed availability, what are some of the keys to a successful program?
In this article, we will explore what species and varieties are available, whilst in subsequent articles, we will delve into some of the establishment and management issues you should be thinking about.
What species and/or varieties should I grow?
Much like the grain crops, there seems to be a ‘revolving door’ of ‘new and improved’ varieties that come on to the market every year.
It can be difficult to know what’s what – but it is important to do a bit of research and seek some advice to determine whether a specific variety will do the job you want.
Plant breeders are becoming very good at developing lines that perform well in a particular environment or circumstance – so understand what ‘job’ you want your pasture or forage to do.
Ryegrass tends to be the main grass species sown for dedicated pastures. There are annual ryegrasses, Italians, diploid and tetraploids and perennial ryegrasses.
Annuals tend to be earlier maturing and finish earlier in the spring. Italian ryegrasses tend to be later maturing, and can provide extended grazing if the season allows. They are often promoted as lasting for two years, but production in the second year is often lower due to low plant densities.
Perennial ryegrasses range in maturity, and tend to have lower production in the year of establishment than the annuals and Italians. Obviously, being perennial, the establishment period in the following season is removed, and they can provide feed over the summer, if irrigated or rainfall occurs.
I’m often asked the difference between diploid and tetraploid ryegrasses. The main difference is the number of chromosomes per cell. Diploid plants have two sets per cell, whilst tetraploids have four. Apart from this, diploid plants have more tillers per plant and a higher dry matter per kg of feed and also more energy than tetraploid plants.
Tetraploids, however, are generally more palatable, often leading to higher animal performance. But because of this they are more susceptible to heavy grazing, and can be more expensive to establish (seed cost and a higher sowing rate is required).
Apart from ryegrass, there are other species that may suit your farming system. For those in the eastern, higher-rainfall parts of our area, species such as cocksfoot and phalaris are highly suited. The performance and persistence of the fescues has also improved, and fescue is certainly worthy of consideration. There are summer active (Mediterranean type) and summer dormant varieties available.
There is a multitude of annual, long-lived and self-regenerating varieties of sub-clover available. When considering sub varieties, understand the rainfall and/or irrigation needs, the hard seeded levels, water logging tolerance, disease resistance and soil type requirements. There will be a sub-clover option available to suit most circumstances in our part of the world.
When considering establishing longer-term pastures, don’t disregard adding lucerne - either as a stand-alone option, or equally, it could be incorporated with a sub-clover pasture.
Whilst there are management and stock health issues that need to be considered with lucerne, there is no questioning its value in being able to provide high quality forage. It will respond very quickly to any summer rainfall or early autumn irrigation, and provided it is managed correctly with rotational grazing, will persist for many years. Provided waterlogging is not an issue, it is well-suited to a range of soils in our area.
Particularly suited to the lower rainfall zone and lighter soils are the medics. Medics are self-regenerating, and are often best suited to crop rotations on neutral and alkaline soils. The forage they produce is typically high in protein, and they have the added benefit, like the other legumes, of fixing nitrogen. They are quite drought-tolerant, and persist well over a range of soils and rainfall zones.
Serradella is also something to consider, and it is particularly suited to lighter, mildly acidic soils in the higher rainfall areas. It is not tolerant of waterlogging, but may be an option on soils with lower levels of soil phosphorus.
All winter cereals can be grazed. The dual purpose, ‘winter’ types (such as Wedgetail wheat) are the most suited, and will provide grazing opportunities longer into the season. The ‘winter’ types require a certain period of lower temperatures (rather than a specific time) before they will go into the reproductive phase - hence the reason they can be sown early.
Grazing any cereal crop will delay the crop maturing. This may be advantageous in reducing frost impact, but can lower yield potential if the crop runs into heat and/or moisture stress.
Forage brassicas can provide quality feed that is high in energy and protein, and can be used as part of the rotation to achieve a disease break and enable grass weed control. Care must be exercised when grazing brassicas, as stock can be more prone to some health disorders such as photosensitisation, nitrate poisoning and digestive upsets. Stock should be gradually introduced to these crops, and have access to some fibre/roughage to aid digestion (brassicas generally have low fibre content).
Less common still are some of the herbs. Two that may be considered in our area are plantain and chicory. They are not widely used in our region, but again may have a role as a short-term pasture option.
Plantain is a deep-rooted perennial herb. Highest growth rates will occur in the warmer months. It can be sown on its own, but is more often used as a component of a pasture mix. It is adapted to low-fertility soils, but does not tolerate waterlogging. Young leafy material is particularly palatable.
Chicory is a perennial herb that has proven to be an excellent source of high quality feed for finishing stock. It has potential for high levels of production over spring and summer – similar to lucerne. Most chicory will be relatively dormant over winter. Whilst there is known to be few livestock disorders associated with chicory, there is some evidence that at very high intake rates, it may lead to milk tainting and acidosis in cattle.
If you are considering blends or mixes of different species and varieties, it is important to match things like soil type and maturity. It makes little sense to plant a quick maturing variety with one that is significantly longer. It is often the case when mixing different species that compromises and management are needed, and therefore production can often suffer, so consider varieties and species that complement each other.
Finally, it is important to remember that any highly productive pasture or forage crop has the potential to cause a range of livestock health issues. Vaccinations need to be up to date, mineral balance must be maintained and it is often useful to provide a source of roughage. Importantly, keep an eye on your livestock – particularly when there is a change in diet or conditions. If using cereals, particularly Wedgetail wheat, a magnesium/calcium lick is essential to prevent sheep losses.
The important things to remember are:
- Understand when and how much pasture or forage production you need – match your species and varieties accordingly.
- Do you want short- or long-term pasture, perennial or self-regenerating?
- Be aware of soil limitations, and plant requirements, before you sow your pasture or forage.
In the next article, we will discuss some of the key agronomic and management considerations when establishing new pastures and forages.
Landholders wanting further advice on their autumn and winter forage options should contact their consultants, advisors or resellers, or alternatively contact a member of the Agricultural Extension team at Murray Local Land Services.