DANDARAGAN farmer Zac Roberts has been using variable pastures to help manage soil type and climate variability on his mixed sheep, cattle and cropping property.
Earlier this month at Meat & Livestock Australia's MeatUp Forum, at The University of Western Australia, Mr Roberts spoke with agricultural consultant and Gingin farmer Phil Barrett-Lennard on how he managed to convert very unproductive country to being highly productive, particularly for his sheep breeding program.
With his family, Mr Roberts' farm business comprises about 15,000 breeding ewes (mainly Merinos) and 500 breeding cows, with 70 per cent of the land being pasture.
Spread over four locations at Dandaragan, Badgingarra and Jurien Bay, the farm has quite varied soil types, ranging from pure white sand to heavy clay and rock and everything in between.
"There's large valleys with good soil loams to unarable rocky hills, to pure sand, so it's very difficult to manage each of those separately," Mr Roberts said.
Mr Barrett-Lennard, who has an expertise in pastures, said Mr Roberts was one of the early adopters of sub-tropical perennial grasses in the region as he sought to make better use of his sandy soils.
Mr Roberts shortened his joining period to 15 days and divided his lambing into two periods to maximise the good feed source that the sub-tropical perennials offer.
Twin crossbred lambs drop abound Anzac Day onto the perennials and are run in mobs of 200 head.
Although the perennials didn't offer much nutrition for the ewes, Mr Roberts said he achieved about a 180pc lambing rate with the lambs dropping onto the fodder.
However, he said it was important to take the ewes out soon after they have lambed so they don't lose condition.
"But the ewes don't leave the birth site, so you are benefitting from the maternal bond," he said.
"The other paddocks where we don't have perennials (the good country), we're having to go around with the feeder, we get mis-mothering and I can only get 160pc lambing at the most within a twin mob on that type of country.
"Here we normally set up a paddock next to it with an annual pasture that we can quickly shift these ewes onto once they've lambed, so they can regain condition, but our lamb survival has been very high, so it's a very good fit for an early drop."
The rest of the ewe lambs are mated for lambing at about July 1 and also drop onto the perennials.
Once the second drop of lambs are taken off the perennials, Mr Roberts then grazes the cows and calves on what's left.
"It's just about trying to use all that feed up," he said.
Mr Roberts has also introduced serradella to grow in between the perennials, which has been a key in making the perennial pasture more sustainable in making use of winter rainfall, as at that time of year they go dormant.
"The feed quality isn't that good especially for a lactating animal, so it's good for maintenance, but as we approach winter and it starts getting cool the grasses shut down and then normally there was nothing growing in between but now that we've introduced serradella, it has a delayed germination anyway, so it can be grazed heavily once we've used up a lot of the grass, then we just lock it up and all the serradella starts germinating," he said.
Serradella has also been incorporated into some of Mr Roberts' cropping land and combined with cereals (barley) to give "the best of both worlds", as it provides some early feed from the cereal and high quality spring feed with the serradella.
"As a system it works quite well - we have two types of legumes and the barley, and it grows a phenomenal amount of feed and can be grazed heavily," he said.
"Especially now with a later lambing, we used to have to shear lamb before all the grass seeds got out at the end of September, but now they can just be put onto these paddocks and they grow quite quickly and I don't have to worry about the grass seeds."
Through experimenting and trial and error, Mr Roberts said he now tries to find the best pasture to fit certain paddocks based on the soil type.
Tedera trial:
Mr Roberts planted a 14 hectare paddock of new perennial legume pasture Tedera as part of a trial managed by Mr Barrett-Lennard, with several Tedera paddocks in the Moora-Dandaragan area.
"When we started this project, we sort of knew that it didn't like white sand but we weren't 100pc sure, so it's gone on a range of soil types but they tend to be better soil types," Mr Barrett-Lennard said.
"It's probably done best at Zac's compared to the other sites but this has looser, deeper soil compared to other sites and it's still only early (only over a year old), so it didn't get grazed in the first year at all and then was grazed for 30 days from mid-May to mid-June."
A mob of first-lambing twin-bearing hoggets was divided into two.
They were rated at two dry sheep equivalent each and 28 head per hectare.
Both mobs increased similarly in condition score and weight.
The mob on Tedera only needed a small amount of supplementary feeding, during the 30-day period of about $1.10/head.
The control mob went onto canola stubbles which had very little feed and required much more supplementary feeding, of about $4.35/head.
"It's very early days in our evaluation of the Tedera, but we think there will be two roles for it," Mr Barrett-Lennard said.
"One is this break of the season which is pretty valuable in helping with the autumn feed gap.
"The other that we will target quite heavily is for the July drop lambs - when they get weaned (about October 1), then this paddock will be spelled and will have a huge amount of high quality feed in it, so we're trying to put on a heap of weight onto the early weaned lambs."
Mr Roberts said Tedera needed to be sown on quite good soil but it was "quite exciting actually".
"I could have put oats and vetch on that soil which would have grown a lot, but I'd have to do that every year," he said.
"This has no economic use for a whole year once it's established, which is an opportunity cost, but once it's there it should be there forever."