Finally an all natural herbicide that REALLY WORKS!!!
Weezap is an organic, natural, non selective herbicide that zaps small broad leaf and grassy weeds. It is made entirely from food grade materials and is safe to use around children and pets. Weedzap is listed as safe in the OMRI (Organic Materials Review Institute).
Weedzap has a long residual effect , but doesn’t damage non-green woody plant parts. This makes it an excellent alternative to Round Up or many other chemical herbicides.
One container of 3.785 litres is enough to cover over 1000sq metres (1183 sq/m to be precise) at a recommended dilution rate of 8% and a water requirement of 43.5 litres.
At this time of year when its warmer this is a highly effective herbicide. You can now buy Weedzap from the Native Seeds online store by clicking here.
Many horse owners have had to face the harsh difficulties and costs of trying to treat laminitis in their beloved horses and ponies (which I will refer to just a ‘horse’ for the rest of the article).
What is laminitis?
Laminitis is a complex illness. You can find many scientific explanations of laminitis online, but we’re going to talk more about how laminitis affects a horse, how it is treated and most importantly, methods of prevention.
Laminitis mostly affects the hoof, or specifically the soft tissue in the hoof known as the laminae. When a horse suffers from laminitis, the laminae becomes inflamed and painful which can cause lameness and distress in the affected horse.
Treatment of laminitis is difficult, time consuming and very costly. In severe cases of laminitis a horse may not survive. Because of the complications of treatment, it makes more sense to take a preventative approach to laminitis.
How can laminitis be prevented?
Before we can prevent laminitis, we need to get a basic understanding of what causes it. There are many causes of laminitis but the most common is the consumption of excess carbohydrates. Grains and pasture contain different sugars such as starch and fructan. These sugars are known as non-structural carbohydrates (NSC).
NSC’s are more present in grasses that are under stress. Many introduced grasses struggle to survive in Australia’s climate and due to that stress build up higher amounts of NSC’s than native Australian grasses.
Studies were done on 2 particular native grasses for their levels of NSC’s: Wallaby grass (Rytidosperma geniculatum) and Weeping grass (Microlaena stipoides). The recommended thresholds are to keep NSC’s below 10 g/100g of the fodder which these two grasses easily fall under having contents for Fructose of less than 0.2, Glucose of less than 0.2 and total sugars of less than 1.0 g/100g. Thus these grasses are very well suited to horse consumption with next to no risk of serious conditions such as laminitis.
Where can I get more information?
You can find loads of information on the technicalities of laminitis on our website, or you can download our 20 page e-book using the form above. The e-book is written by our agronomist Dr. Ian Chivers and reviewed / approved by Jane Myers, Prof. Chris Pollitt and Rebecca Scott and has more than enough information to get you up to speed on how laminitis works and how you may help to prevent it from happening to your horse.
As always, we hope you enjoyed our article.
Picking your grass: Locally Harvested or Selectively Bred?
Many supplier of Australian native seeds obtain stock through harvesting seed from remnant stands of vegetation in a specific geographic area, we have termed this ‘locally harvested’ grass seed. This technique allows for tracking of seed ‘provenance’, but may have variability in the quality and quantity of seed available, as well as potentially depleting the seedbank in remnant stands of vegetation.
At Native Seeds we have taken a different approach; we have ‘Selectively Bred’ our grass varieties. Through collaboration with a number of government organisations and institutions we have bred varieties of Australian native grasses with certain traits. For example Griffin weeping grass has been bred for its low mowing requirements, high shade resistance and low fertiliser requirements making it ideal as a native grass lawn. We produce these varieties in an agricultural setting and all seed is Australian Seed Federation accredited to ensure that you only receive high quality seed.
The question often arises as to why the use of ‘selectively bred’ varieties of native grasses rather than ‘locally harvested’. Our reasons are:
- The selected types have been selected for specific purposes. The characteristics that they have been selected for gives the purchaser a guarantee that it will do as it is desired. Buying seed that is locally available cannot give you that guarantee.
- They are grown under highly managed conditions where they are harvested at their peak, where weeds are controlled and where inputs such as water and fertilizer are provided as needed. The locally collected material is just that- it is collected, often without any weed control, usually without any inputs and mostly it is harvested when it suits the operator, not necessarily when the seed is best.
- The selection has usually been done for some highly significant factor which has real practical implications. For example comparing two varieties of weeping grass (Microlaena stipoides). The one called Ovens has been chosen as it has high seedling vigour and adaptability across many soil types. While the variety Griffin has been selected for finer leaves and more dense foliage.
- Other varieties have been chosen for their tolerance to frost, for size, for seed yield, or for a combination of those factors. The characteristics that have been used in the selection process carry through into the next generations and will help get the desired results.
- They have been evaluated across a range of sites and only the best have been retained. Breeding programs are slow and elaborate processes that involve assessments across multiple sites. As an example the CSIRO breeding program that eventually gave rise to Tangara Kangaroo grass involved assessment on four sites of wide geographic range and showed the ability of this variety to perform well in a range of different environments.
In summary, there is a lot of time, money and research involved in selecting the best of the best varieties of each grass type. Next time you choose which grass you want, for example Wallaby grass, think about the characteristics you would like this grass type to have. Do you want it to reach up to a metre in height for pasture or revegetation? Or do you want it to reach a maximum of 30cm for a lawn, park, golf course etc? What kind of soil does it need to grow in? How much heat, drought or even frost will it need to tolerate? Whatever your conditions the Seed Consultant’s at Native Seeds will be able to provide you with guidance as to what species will work best for your conditions and purpose.
Any investment manager will tell an investor to spread risks, to have a diverse portfolio, to engage with many sectors of the local economy, to invest in other parts of the globe, to hedge your bets, a mix of shares, real estate and cash – we have all heard this advice. And for the most part we agree with it and do our best to abide by it. Yet we do not take the same approach to our own sustenance. Unlike the savvy investor, humans have an unparalleled reliance upon just a few forms of cereal grains. This is of concern given that grains provide the bulk of nutrition to almost all of the world’s billions of people.
Seeing the limits of the current system
Before exploring where new value might lie, it is important to understand where the threat to value lies in the current system. Now in most parts of the world we mostly rely on only eight or so species of plants for grains. Given their pervasive nature they are easy to name quickly: wheat, rice, maize, sorghum, oats, barley, rye, and millet. There are a few others that are consumed in smaller quantities, but overall we have a very heavy reliance on this small number of species. Our investment adviser would be telling us that this is too narrow a portfolio and that we should be broadening it to spread risks.
The other notable fact about this short list is that most, if not all, are annual plants. These plants do not persist for more than one season, for the most part remove rather than add carbon to the soil and, as they die each year, they leave the soils free of living green matter. This lack of living matter means that they are unable to absorb rainfall if it falls at that time.
Altogether there are too many eggs in the one basket of annual cereals as the principal source of foods for the world’s billions. These plants require significant investment in terms of time and money. It starts with annual resowing, with all the risks of failure and high costs involved. Repeated cultivation has been shown to remove soil organic matter and so reduce the ability of the soil to host beneficial microflora, to absorb water, to be soft underfoot (remember soft soils? They are a thing of the past in much of Australia), to retain nutrients and to smell and feel good. Anyone digging up soil on dedicated cereal cropping farms in most parts of Australia will, apart from deciding that they need a crow bar to get into the soil, notice the absence of worms and that lack of strong earthy smell. Surely this is not a system that offers the long term benefits that come from healthy soil.
Production of these crops not only strips the soil of essential nutrients that must be replaced or else production will fall, but it also requires the use of selective herbicides to remove weeds. Many of those same weeds are now developing resistance to those chemicals. This implies a need to either use higher doses of the same chemical or change to another chemical and start all over again. In short, total reliance upon annual crops is a one-way street to oblivion. It is a system that can produce grain, but does so at the expense of the soil and of the environment.
Significant risks are found at many stages throughout the growth of the crop. At sowing time inadequate rainfall can reduce stand density and may indeed dictate a repeat sowing. During the growth stage again inadequate rainfall might not allow sufficient plant growth to stimulate reproductive stem formation. Finally at harvest time too much rainfall, ironically, can ruin the crop.
It is also a system reliant upon petroleum for fuel to sow, harvest and manage, for fertilizers to promote growth, for herbicides to control weeds and for insecticides to reduce pests. In a world where crude oil will never be cheap again, and along with that other inputs such as fertilizers, growers of annual crops are continually seeing their costs of production increasing. Perhaps breaking the link between expensive oil and grain production should be at the forefront of 21st century practice?
Seeing new options through history’s lens
What we need to do is to look around at other systems and see if they can be used. In Australia we have stunning examples of very long-term grain-food production that had no degrading impact on the environment, that did not require expensive fertilizers or pesticides, and grew without the need for irrigation water to be diverted from river systems. These long term cereal production systems were a feature of Aboriginal-Australian farming systems for thousands of years.
It is not well known that Australian Aborigines used our perennial grasses as grain sources each year for food, usually in the form of a damper, and had well-established methods of production. The region where this was best known was called the Panara by early European anthropologists and extended in a large swathe from the Flinders Range through western New South Wales, north through central and western Queensland, straight through the Northern Territory into the Kimberley and then south into the northern wheat production areas of Western Australia. In the shape of a donut with a bite removed covering the Great Australian Bight, this area covered more than one quarter of the total landmass of Australia. In this huge area Aboriginal Australians kept themselves fed with grains from our perennial grasses and supplemented that basic diet with other bush foods.
The existence of this managed grain production system was novel to the early European explorers, like Sir Thomas Mitchell, who wrote: ”In the neighbourhood of our camp the grass had been pulled to a very great extent, and piled in hay-ricks … extending for miles … (that) had evidently been thus laid up by the natives, but for what purpose we could not imagine”. It took later botanists and anthropologists to determine that the Aborigines had been using these ricks (windrows) to ripen the seed, which was then collected, cleaned, stored, and used to make a bread-like damper.
So why do we not look to use the same sort of system for grain production now? Maybe Australian cereal breeders should become more aware of Australian native grasses and the existence of the Panara. Sure, we are not in a shifting hunter-gatherer society any longer, and I am not suggesting we revert to those practices. Rather, I am suggesting that we look at the species that were used by those clever societies and see if they can be adapted to form part of a new production methodology that is more sympathetic with the realities of Australia, and indeed the globe, in the 21st Century.
A new production system using perennial grasses
We need to be looking at perennial grasses for our new grain types, not annuals. As it happens, Australia has many suitable grain-production candidates amongst its perennial grasses. It is not the purpose of this essay to discuss the merits of each of the candidates, rather to encourage people to think more broadly about their choice of species and then to look closely at some of the Australian native options and opportunities.
But what would a new production system look like? There are many different models and they will vary from region to region, but I suspect they will have several consistent features. They will be perennial, they will match the rainfall zone and be permanent and persistent pastures in each zone, they will be palatable to domestic stock, they will be harvestable for grain using conventional equipment, and they will have grains that are easy to thresh.
Can you imagine a permanent pasture that also produces a grain crop in those years when the rainfall amount and timing permits? It would also be the pasture that is able to survive the drought that will inevitably occur without the need to resow once the drought breaks. In another area with another grass pasture and crop, it will be the permanent pasture that grows vigorously under the trees, that produces a grain crop at the end of the wet season but still does not compete for moisture during the dry months. It would be a new world of true dual-purpose crops – where farmers have the options to simply graze a paddock or alternatively to graze it for a shorter period and then to let it run up a grain crop. This is a perennial grain-cropping system as it was used in the long-time past but which is still there for the discovery if we are wise enough to look.
Time to think, time to act
This is a low-risk, low-cost system that is sadly not known to most plant breeders. What is horribly clear however is that continuing to invest in breeding of the existing cereal species looking for a variety that might be slightly more drought tolerant means continuing to favour a system that degrades our soils and environment. Is it not time to rethink? Why not be active and systematically collect potential crop plants from around Australia? Why not go to marginal environments and find those native grasses that grow there already to see if they can be adopted for use in modern farming? Why not broaden the thinking of the plant breeders and give them opportunities to be creative in their species selection? It would be to the good of us all.
Feel free to leave a comment below.
African Love grass control part 3 – Establishment of Native grasses to compete with African Love Grass
Ian Chivers, Native Seeds
In the two previous articles I have talked about the different characteristics of the
grasses and in particular the Australian native grasses and how they might be used
to prevent the encroachment of pastures by African Lovegrass. This article aims to
give people simple instructions about how to get the grasses established and how to
get the most out of every kilogram of seed.
It might seem obvious but I need to stress to everyone that just because the native
grasses are able to grow on compacted soils and with little rainfall, that is not the
way to sow them. They, like any grass, need to be sown into a condition in which
they can establish successfully and develop deep and fibrous roots. Broadcasting
the seed onto compacted soil and hoping for a result will not give you one but sadly
this has happened in the past. They need to be sown into soil that is free of weeds,
decompacted and with sufficient niches to allow for the seeds to be surrounded by a
mix of fine soil particles, moisture and air.
This may not mean a full seedbed such as would be prepared for a lucerne sowing,
although that would work well, but it involves as a minimum killing off weedy growth
on the surface, creation of grooves or niches in the soil and burial of sown seed.
Taking each one of those in turn, killing off the vegetation can be through chemical
means such as Glyphosate or through some organic chemicals such as Pine Oil or
other essential oil compounds. At the moment we are trialling a new organic
herbicide (not Pine Oil) that involves a range of different essential oils which operate
in a different manner to herbicides such as Glyphosate and which are seemingly
equally effective at killing off the foliage. This organic herbicide does not have the
problems of residual chemical and off-target effects that are being reported with
herbicides such as Glyphosate. Maybe I can talk about that more at some future time
when we have more experience with this product.
Creation of grooves in the soil surface can be through rudimentary means such as
dragging harrows or even a spiked roller over the surface. The grooves do not need
to be continuous or deep, as long as they are creating a niche where the seed can
fall. The niche need only be around 5 to 10 mm deep.
For some grasses the use of a deep litter layer can work very well to provide a
sowing medium and indeed this can be applied directly over compacted soil. We
have done this very successfully with grasses such as Weeping grass (Microlaena
stipoides) as it is very able to punch through deep litter layers, even as a seedling,
and emerge strongly. I did this once in an unplanned way where some seed was
sown and then a load of sheep droppings were placed over it. Even in those places
where 100 mm (4 inches) of droppings were dumped the weeping grass emerged!
This grass is well adapted to this circumstance. Maybe this method could be applied
on rocky areas where cultivation is impossible. I know that we sell a lot of seed for
sowing blended in with a fine compost onto bare areas such as roadsides and the
results are very good.
Ignoring the step of seed sowing for the moment, let’s go to seed burial. Once the
seed is on the soil and has found its way into the niches, it needs to be covered by
soil. The germination rate of seed on the surface is less than half that of seed that is
slightly buried, so it is vitally important to cover the seed in some way. This allows the
seed to remain moist which is really the key to good germination success, especially
with the cool season grasses. To achieve this is less difficult than might be imagined.
Simply dragging a sheet of mesh or some old heavy cloth will shift soil that is loose
into the niches and cover a lot of seed. There is a less effective but cheaper option of
bringing in a large number of stock to shift the soil, a favourite tactic use in New
Many people get hung up on this and try to find elaborate precision methods of
getting seed into the soil. My advice here is not to let this step be the make or break.
With some of the native grasses the seed is very fluffy and chaffy. It will not sow
evenly in that form and you are better off buying seed that has been pelletised. While
you get fewer seeds per kilogram of seed and you are paying for the clay and
colouring, it does help get the seed onto the soil in the area where it is desired. It is
definitely worth the cost. I expect some of you will have tried some seed balls where
big balls of clay the size of marbles are impregnated with seed (usually trees) and
they can then be spun out or tossed out onto the soil. The concept is that with rainfall
the clay will melt away and in effect create an instant seedbed for the accompanying
seed. The same concept applies here for the grass seed, except the coated grass
seed is much smaller than marble size.
For small areas sowing seed from a bucket, like feeding the chooks, is quite
legitimate and successful and it is surprising how much area can be covered in a
Seed treatments are now available for the native grasses that allow even those with
long awns to be sown through most spinner-type spreaders, so they are no longer
impossible to sow evenly.
One step that I always encourage people to do is to establish some monitoring
points. Usually putting two pegs in the ground about 1 metre apart and sowing
heavily into a well-prepared groove between those pegs will provide a reliable and
useful monitoring point. This helps both to show when the seedlings are emerging
and what they look like. This makes the evaluation of the success or failure of the
sowing to be more realistically undertaken.
Fertilizer for sowing
Applying fertilizer to a native grass sowing? I hear you ask. Yes I do recommend it
and this is probably the only time in the life of the grass that this is really important.
Usually the seedlings will go through a phase about 6 weeks after they emerge when
they will benefit from an application of a nitrogen fertilizer to help grow a strong root
system and more foliage. Applying moderate rates of N at 6 weeks of age will give
substantial benefits to your sown native grasses.
I do not recommend sowing and applying fertilizer at the same time as this will
usually benefit the weeds more than it will the native grasses.
What about Lime? No thankyou. These grasses are really well adapted to low pH
soils and applying lime will only benefit the weeds.
Or gypsum? I am not opposed to gypsum applications when they are warranted on
the basis of a reliable soil test. Just be wary of applying too much at any one time
and remember the effect of gypsum is slow and cumulative, and to get good results
you will need to apply it consistently.
What to watch out for
I have lost seedlings of native grasses to Red Legged Earthmites and Gnats so I am
quickly warning you of them. You should keep an eye open for these pests. Less
likely are problems such as Damping Off and Fusarium, but you might need to be
watching for them.
I know that severe and repeated frosts can kill off seedlings of many native grasses
in their early stages, so picking the time of year to sow is also important if you are
subject to those.
Things that are coming soon
Technology is emerging around seed treatments prior to sowing that increase the
stress tolerance of the seedlings and will help to prevent seedling deaths. This will
be amazingly helpful in achieving good sowing results.
New seed treatments are also emerging that are taking difficult-to-germinate seeds
and making them far simpler. A recent test of one of our weeping grass lines raised
the germination rate at 7 days from 23% to 75%, so this is looking very helpful.
When these technologies are verified and scaled up we will be trying to tell everyone so keep your eyes peeled, it might be only a year or so away.
All the best with your sowing of native grasses.
Dr. Ian Chivers
Ian Chivers, Native Seeds
In the first article of this short series I talked about the growth patterns of the cool
season grasses and how they varied from those of the warm season grasses. I
suggested that we can use the different growth habits to provide strong competition
to African Lovegrass (ALG) when it is at its’ weakest at the early seedling stage in
Spring. Using a strong growing cool season grass cover to compete with a warm
season seedling is a very useful tactic that has been shown to work on other weeds
and can be utilised to great effect on ALG.
What Cool Season Grasses?
So what cool season grasses are best to use? The ones with which we are most
familiar are the introduced favourites – ryegrass, phalaris and cocksfoot. We have
grown them for decades and we all know their limitations – for the most part that
comes down to lack of persistence for ryegrass; very slow establishment, potential
death for grazing animals through staggers and intolerance of acidic soils for
phalaris; and slow establishment along with higher fertility needs of cocksfoot.
So what about some of the native grass options? Generally speaking the native
grasses, owing to their long-term adaptation to Australian soils and climate are well
suited to growth here. But which ones? The three that I will focus on for this article
are Wheat grass (Elymus scaber), Wallaby grass (Rytidosperma spp.) and
Weeping grass (Microlaena stipoides).
Wheat grass is a vigorous cool season grass of high pasture quality and,
surprisingly, high vigour. Many native grasses are noted for their slow establishment
and relatively low biomass production, but wheat grass is an exception. Our native
wheat grass (Elymus scaber), sometimes called common wheat grass, is a
widespread cool season native grass that can produce similar volumes of foliage to
perennial ryegrass and indeed looks quite similar to that grass. It is highly persistent
through drought and would be more widespread except that it is quite highly
palatable to stock and is readily eaten out. This is usually sown in autumn or early
What is intriguing to me about this grass is the green material it produces over the
summer. Our seed production stands remain green throughout the summer, even
after the seed has been removed. Any summer rainfall promotes rapid growth. Just
as a caution, a really harsh summer will deplete this grass, if it is set stocked or heavily grazed. Incidentally it is now recognised as being one of the most valuable
fodder grasses for horses owing to its significant bulk of dry matter combined with
high starch and low sugar content.
Just to make sure here I want to spell out that this is not Tall Wheat grass, which is
an introduced grass that was recommended for saline areas. It too is now becoming
a weed concern across much of southern Australia. And just to be complete I also
need to make the distinction around the drink made from munched up seedlings of
wheat – that also is not the wheatgrass about which I am talking.
Wallaby grass really refers to a whole family of grasses, not just one species. Indeed
there are roughly 30 to 40 species that are commonly called ‘wallaby grass’ or ‘white
top’. The taxonomists will tell them apart by the nature of the hairs on the back of the
seed and the awn, but for most of us the biggest differences are in their mature size.
There are large leafy types that can be as tall as 1.3 metres and small types that
reach no higher than 0.1 metres high. They are generally described as highly
persistent species, very drought adapted and suited to poor soils, but as you can
imagine with such a wide range of species growing naturally across southern
Australia there are types that grow almost everywhere – from saline soils, to stony
ridges, to waterlogged soils and even to lawns.
In animal nutrition terms they are comparable to many of the introduced grasses
when at their peak, and I think here specifically of types such as Bunderra that have
been selected by the NSW Department of Agriculture for pasture use.
Then there are other types such as Hume which was developed by the CSIRO in
Canberra specifically for roadside and other low-maintenance uses where
persistence is the most desirable characteristic rather than dry matter. Another
variety that we have developed is Oxley which is small in stature and has been used
extensively in between rows of vines or in lawns where persistence and low biomass
production are specifically desired.
Weeping grass (Microlaena stipoides) is another very useful grass type that has a
huge potential for use in pastures around the southern tablelands. It is very well
adapted to acidic soils, drought, grazing and shade. It is often the first grass to come
back once a drought breaks and provides high quality fodder, especially for cattle. It
is naturally occurring across all of the higher rainfall and cooler zones of southern
Australia and has a huge natural diversity. Weeping grass is able to produce a lot of
highly palatable foliage with relatively few inputs.
Some varieties have been developed for particular purposes such as Ovens and
Wakefield for pasture, Griffin for turf and amenity and Shannon and Bremmer for
revegetation. These varieties give landholders the ability to choose a particular
variety especially for their desired use.
While the establishment of weeping grass is slower than some other species, it is
very strong once established and will persist for decades once sown. It is also able
to recruit well for the following generations and will spread readily if conditions suit it.
Once again there is a large range of spear grass types, the Austrostipa family, many
of which occur naturally across the southern tablelands of NSW. They are less
palatable than the other grasses I have been talking about and have the major
detraction of a very sharp and intrusive seed (hence the name). While these are
amongst the hardiest of the cool season native grasses to be found in the area with
many persistence benefits, the difficulties caused by the seed limit where these
grasses can be used. The most common applications for deliberate sowing are in
non-grazed areas such as roadsides, steep cuttings and so forth.
Seedlings of spear grass are relatively slow to establish and remain small for a
lengthy period. If they are not trampled or smothered they will grow out to be
substantial plants after about 18 months.
It is by using these grasses cleverly as competitors against the new seedlings of
ALG, that some strong competition can be established which can help to prevent the
invasion of that weed. The strategic use of native grasses offers the potential to gain
a valuable pasture that needs few inputs and which can be highly competitive
against encroachment by ALG.
In the next article I will talk about the methods of establishing these native grasses.
Dr. Ian Chivers, Native Seeds P/L
African Love Grass (ALG) is a substantial problem for graziers, croppers and
environmentalists on the southern Tablelands of NSW. It can lead to the virtual loss of
grazing pasture, the removal of nutrients water and diversity from a paddock, a hillside and even an entire farm by its aggressive growth accompanied by its unpalatable nature.
Yet at the same time, it is possible to see areas where stands of native grasses occur
alongside and butting up against encroaching ALG. How is it possible that the native grasses are proving more competitive against ALG in comparison to some of the introduced grasses?
Is it possible to use this capacity to fight against the encroachment of ALG? If it is, how will it be done? I hope in this series of articles to provide some thoughts about these questions.
We need to start with what we know about ALG. (I also need to provide some basics of plant physiology, but more about that in a few moments).
So what do we know about ALG? Firstly, ALG spreads by seed. Secondly, it invades areas that are disturbed in some manner. Thirdly, it has a peak germination period of mid to late spring as temperatures rise and day length increases rapidly. Fourthly, it sets seed in late summer and early autumn, with that seed largely being dormant until spring of that year.
Fifthly, the seed store of ALG does not last very long in the soil and most will die within a couple of years of dropping onto the soil.
ALG is at its weakest when it is a seedling. It is not a highly competitive seedling and canbe
out-competed by a strong stand of actively-growing plant matter.
To be specific, ALG seedlings are susceptible to desiccation, and possibly shade, while they are smaller than the 5 leaf stage. These seedlings can be prevented from growing further by strong competition for resources at that time.
To take this further I need to provide some basic plant physiology. A basic understanding of this will help to make clear what I am going to describe later on. Grasses can be divided into two groups – the cool season and the warm season types (sometimes described as the C3 and C4 types for reasons of their biochemistry). The cool season types are those that grow during the cooler times of year and which either go into dormancy or die during summer.
Some well known examples of these are ryegrass, cocksfoot and phalaris. They remain green during frost periods, grow strongly in early spring and are mostly intolerant of high
temperatures. In contrast, the warm season types are those that germinate during spring,
grow actively during summer and will go into dormancy, or die, over winter. Some examples are kikuyu, couchgrass and the fodder crops of maize and sorghum. Generally the warm season types are more heat and drought tolerant than the cool season types. ALG is a warm season grass.
The basic form of the growth pattern of cool season grasses on the Southern Tablelands is as shown in graph 1. The features of greatest interest to pastoralists are the periods of active growth in autumn and spring. Of recent years the autumn rainfall has been limited and hence this small peak has often been negligible and most reliance has been placed on the spring period for active and substantial pasture growth.
In general there are two periods during which germination of these cool season grasses
occurs – in autumn and in early spring. The warm season grasses have a very different growth pattern to the cool season grasses (Graph 2). The main features here are the absence of growth over winter and the strong growth over the late spring and early summer. Germination for these grasses occurs in mid spring and the plants tend to grow very quickly once they germinate.
The differences between these two growth patterns provide an opportunity to influence the growth of the emerging warm season grasses, and especially the ALG. By applying strong cool season growth in early spring the chance of good establishment of weeds such as ALG is substantially reduced.
We see this regularly as ALG can only get established on areas in which the cool season cover is either degraded or removed. This can occur through
achieving good seedling establishment in autumn, or possibly in early spring, and having
those cool season grasses established and competitive with the ALG when it germinates and tries to establish in mid spring.
ALG seedlings can be suppressed by competition for water, light and fertility. This will occur with a vigorous growth of cool season grasses that are actively growing at the time when ALG seedlings are young and trying to become established.
In the next article I will talk about the various options for providing that competition to the
emerging ALG seedlings.
Graph 1: The relative growth rate of cool season grasses such as ryegrass and phalaris during an average year on the southern tablelands of NSW
Graph 2: The relative growth rate of warm season grasses such as African Lovegrass, kikuyu and couchgrass during an average year on the southern tablelands of NSW. Note the absence of growth during their dormancy period over the winter months.
In response to a recent email, Dr. Ian Chivers gave some great information on how to successfully sow native pasture.
“The success from sowing is strongly dependent upon the preparation that can be put in. The more weed control you have completed prior to sowing the better. Similarly the more of a seedbed created prior to sowing the better.
At one end of the spectrum there is simply sowing onto existing pasture with no seedbed preparation which will yield very few seedlings and the pasture will not change much. At the other end is full seedbed preparation involving cultivation (possibly chemical as well as mechanical) and drilling seeding into the top layer of soil – this will yield the greatest results. In between are a host of alternative methods, dragging harrows and broadcasting, broadcasting and then running sheep over to trample the seed in, mulching after broadcast, drilling over denuded areas, and so on. They all will yield intermediate results.
The key ingredients are to remove as much as possible of the existing weed burden and to create a method for getting the seed into contact with the soil, and preferably buried under 5 to 10 mm of soil. These steps are important as they will help to firstly remove weed completion to the emerging seedlings and hence to increase survival rates through to maturity. Secondly they help to keep a higher content of moisture in the soil around the seed, which for most species is the trigger for germination.
If you are sowing our Gallop horse pasture it is best sown in the cooler months when there is adequate moisture retention around the seed, so for you in WA the sowing window will extend from April until around September.
Once sown please keep the horses off the area for at least 5 months until the plants are large enough to tolerate trampling and grazing. I would encourage you to allow one season of seed production prior to grazing if that is possible.
A handy hint her is to put two pegs in the ground about 1 metre apart in a place which is typical of the paddock and where it is easy for you to examine. Into this row sow a single row of seed and bury it. This will then become your guide as to seedling germination and identification. It will tell you when your Gallop Grub horse pasture is germinating and what the various seedlings look like. Remember they are not all going to germinate on the same day, but at least it will show you exactly what is coming up.
I hope this helps.
With only a little over 1 month until the carbon tax hits us, carbon emissions and how to reduce them is a huge topic at the moment.
What effect does carbon have on the environment?
Carbon pollutes our air, increasing the “greenhouse effect” or “global warming”. Temperatures are said to rise. Polar ice caps said to melt. But it also plays a detrimental role on the environment and our own health.
So what does this have to do with grasses?
Just about everyone knows that trees store carbon. But did you know that grasses also play a major role in carbon storage?
Ok, so why native grasses and not just any grass?
When trees break down, either rapidly in a fire or slowly through death and decay, the carbon that was in their foliage is returned to the atmosphere. Thus tree carbon is only a relatively temporary solution to carbon sequestration.
When grasses die, the leaves decompose and also release carbon back to the atmosphere. So the selection of long-lived grasses is important if your aim is to provide a long-term carbon sink. Clearly native grasses are highly persistent in their natural environment and are a natural choice for this purpose.
Ok, ok… so what does this have to do with me?
Well, possibly nothing or possibly a lot. We just hope that with this valuable nugget of information, you will at least consider (or continue to consider) native grasses as an alternative to the cheap, low quality introduced grasses that can actually be harmful for our environment both in terms of carbon and in terms of fuel load for fires (which you learn more about from Bob Myers in this video).
Thanks for reading and as always if you have any questions, please don’t hesitate to call us on 1300 4 73337 or email to firstname.lastname@example.org !