Species selection supports enterprise diversity
Case study: Richard and Emily Gardner
Location: Tunbridge, Tasmania
Property size: 2600 ha
Average annual rainfall: 465mm plus pivot irrigation
Soils: Highly variable shallow duplex soils — sands to heavy clays
Enterprises: Mixed farming system — 750 cow dairy, sheep (prime lamb + wool), irrigated (230ha) and dryland pastures and irrigated cropping (poppies, grazing winter cereals)
The pastures across Richard and Emily Gardner’s property Annandale in Tasmania’s Midlands have to be fit for purpose in what is an impressive and complex mix of irrigated and dryland enterprises. Throw into the bag an assorted range of soil types and a highly variable climate and you’ve got a management challenge that requires a delicate balance of a strong operations plan and timely decision making.
For Richard and Emily, a carefully chosen mix of perennial pasture species offers a resilient, flexible and productive feed source that complements both the livestock and cropping components of their diverse enterprise mix.
“The reasons Tasmanian farms can sustain diverse farming systems is that our properties are diverse by nature,” Richard said.
“On Annandale we have native run country, with shallow ironstone soils that we largely manage for conservation values, through to fertile country ideal for livestock, dryland and irrigated cropping, including poppy production. The establishment of sizeable irrigation scheme in the Midlands means we have recently incorporated a 750 cow dairy into the mix.
Our system hasn’t always been that diverse — the decline in returns from sheep forced us to look harder at other options, such as irrigated cropping. The benefits from this evaluation process are manifold — our risk is spread across multiple enterprises and the returns from irrigation have allowed us to increase our ability to manage our native areas sustainably.
We have moved from set stocked wool production on our native country to managing most of this country for conservation values under a management covenant (25% of the whole property is managed for conservation outcomes).
When sheep were our major focus, every blade of grass across the property was vitally important, forcing us to extensively graze our native country. We now graze very little of our native country and our perennial pastures are the backbone of our livestock operations.
We have developed a mix of pasture species that offers year-round feed production (in conjunction with our crop stubbles, dual-purpose cereals and hay and silage production), feed quality, palatability and drought resistance.
Perennial ryegrass and white clover — high-productivity pastures
Perennial ryegrass and white clover form the grazing platform of our dairy operation — we have 230ha under an off-the-shelf high-productivity combination, which incorporates a mix of diploid and tetraploid perennial ryegrass varieties and white clover.
Establishing the white clover component of the mix is the real challenge. To date our best success has come from a two-pass sowing approach — in the first pass we sowed 75% of the ryegrass seed and we went back with the second pass, at an angle to the first, with the remaining 25% of the ryegrass and 100% of the clover. We also changed the sowing depth for the second pass — making it a bit shallower for the clover. It worked well.
One of the keys for us is that we are establishing under pivots, so we can manage risk by managing the moisture on the surface. This allows us to be less precise with the seedbed preparation.
Utilising livestock to manage pastures
Currently we are using our 300 yearling heifers to manage the excess growth in these new pastures — to get on top of the excess feed. Later they will be used to manage spring growth on our dryland sheep pastures, which are predominantly phalaris, with some ryegrass.
Sheep still form an important component of our operation — even with irrigation, we still have a significant area of dryland pasture that can’t be reliably used for cows during the winter— we don’t even incorporate that country when we do our feed budgets because the seasons are so unreliable.
While perennial ryegrass arguably outperforms many species in terms of feed quality and palatability, in our dryland paddocks it is not ideal where you have pasture grubs and highly variable seasons.
We have the right combination of season and stocking rate in about three years in 10. Although the ryegrass is relatively low-cost and easy to establish, it outcompetes companion species if grown in a mix and disappears when things get tough — leaving nothing. In saying that, it still plays a role in our system.
Where we have sub-optimal spring sowing conditions for our other pasture species, we can follow up with ryegrass during autumn for lower cost and risk. In terms of resilient pasture species that will persist across variable seasons, we have had to look elsewhere.
Lucerne delivers multiple options
Further from the dairy we have irrigated lucerne pastures, which we use for hay and silage production (to supplement grazing for the dairy cows during winter) and fattening lambs. The lucerne also plays a key role in our irrigated cropping program — a four-to-five-year lucerne phase followed by two years of poppies.
We’ve recently shifted to a more winter-active lucerne variety (10 score compared with 7 score) and the growth has been phenomenal this winter. The winter-active lucerne is ideal for our cropping rotation as it establishes quickly and we are looking for year-round production.
We use the lucerne to control annual ryegrass before the poppies (through grazing, fodder conservation and non-selective herbicides), which is working well. It also means we use less nitrogen in the first poppy crop following lucerne, which is and added bonus.
We kill the lucerne in March–April before it starts to slow down and come in during August–September with the poppies.
Not all of our irrigated cropping country is suitable for lucerne, so we also grow a few grazing cereal crops (oats, wheat, triticale) following poppies. Unlike the lucerne, the cows can graze these paddocks during winter or we can use them for hay and silage production.
Dryland lucerne is also an important part of the livestock part of the operation because of its seasonal versatility — response to small amounts of summer rainfall — lucerne is so responsive to compared with the grasses.
Dryland phalaris proves persistent under pressure
Phalaris is the other key pasture species on our dryland operation. While it doesn’t respond like lucerne to the summer rainfall, it is persistent. Persistence is the real key for these dryland perennial pastures.
You need a certain amount of productivity and palatability but you just don’t want to keep going back and re-sowing pastures. In saying that, the other benefit of phalaris is that we sow it during spring, which reduces the risk we face with an autumn sowing.
Drought has taught us a lot about managing pasture — conserving important pastures through sacrifice paddocks and drought lots. It highlighted the benefits of phalaris and lucerne as resilient, drought-tolerant species.
From a drought-tolerance perspective, we could run a phalaris-dominant system, but during the past couple of wetter seasons the challenge has been managing feed quality. Phalaris is great, but managing growth during a big season is difficult.
Traditional cocksfoot varieties have been drought tolerant, easier to manage in terms of feed quality, but have had palatability issues. We grew Uplands cocksfoot for seed production for a few years and it remained drought tolerant, and was much improved in terms of palatability but it was crippled by grubs (cockchafers).
Farming is always challenging, but developing a complementary mix of enterprises and finding the best pastures and crops to support those enterprises certainly helps to achieve a productive, profitable and sustainable balance.
Contact: Richard Gardner, Annandale
M: 0419 374 511
For a range of technical resources to guide pasture species selection and management in Tasmania please click here