Pushing the pasture phase for profit
Better transitioning between crops and pastures and managing both phases well can be the key to lifting farm profitability in the medium and high-rainfall zones of Western Australia’s southern wheatbelt.
This is borne out by the work of Planfarm consultant Paul Omodei, who is working with Muchas Gracias grower group members in Arthur River and Wagin to evaluate a range of tactics for optimal integration of pastures into cropping rotations – and improving pastures coming out of a cropping phase.
He says managing these transitions better and pushing pasture productivity in this region have potential to increase crop and livestock production, reduce weeds for the cropping phase and boost whole-farm income.
“The keys to this strategy are to dry sow and create density in pastures to run adequate stocking rates that make money, while attacking the annual ryegrass (Lolium rigidum) seedbank problem for the cropping phase,” he says.
“Pasture density comes from sown cereals and stimulated hard-seeded annual ryegrass and subclovers that may have stayed dormant without physical soil disturbance.
“The cereals and grasses drive the winter livestock carrying capacity and the clovers produce the nitrogen for following crops – as well as setting seed and contributing to the clover hard seedbank, which will be there following the next crop rotation.”
Three-year on-farm demonstration trials have been set up by the Muchas Gracias group in conjunction with the Department of Agriculture and Food, WA (DAFWA) through the GRDC-funded Grain & Graze 3 project ‘Crops to pasture – pasture to crops’.
Wagin growers Bryan and Jane Kilpatrick have a trial investigating pasture-crop rotations, the effects of cultivation on weed germination and the amount of extra feed produced from adding nitrogen in the pasture phase.
In 2014, the first year of the trial, they sowed Wandering oats (at a rate of 40 kilograms per hectare) and Dalkieth clover (at a rate of 8kg/ha) using narrow AGMOR sowing boots into dry pasture on 24 April.
There was no pre-seeding herbicide used and they applied 40kg/ha of monoammonium phosphate (MAP) fertiliser.
Bryan says the aims were to boost soil-water infiltration and plant density, stimulate weed germination and provide early feed for livestock.
He says there was a cultivation effect on weed numbers and growth in that first year.
Geranium (Erodium species) and capeweed (Arctotheca calendula) got away early and started smothering the clover and oats, forcing Bryan to spray with a phenoxy herbicide.
“After that treatment, we had a good stand of oats, clover and annual ryegrass and were able to use this for two intensive grazing periods in June and July,” he says.
“Part of this trial is to assess how much extra stockfeed is produced by the sown pasture, as we usually experience a feed gap between seeding and lambing [in early July].
“The oats certainly provided a bulk of feed early in the season last year, which was very helpful and, in a different year and on a bigger scale, could be crucial because we carry a high percentage of lambing ewes.”
Bryan says a combination of improved pasture paddocks prepared earlier in the year, deferred grazing on long-term grazing paddocks and some crop grazing is ideal to set up paddocks for his lambing period.
He says crop grazing has a place in the system and is used when conditions allow on well-established paddocks with low weed burdens.
“Our preferred strategy is to defer as much as possible the planned wheat paddocks, sow canola, oats and barley as quickly as possible, and then slow down to finish the wheat,” he says.
“This spreads our wheat sowing dates and allows pastures to get away.”
The Kilpatricks use spray-topping in spring to reduce the grass component of pasture paddocks, while being mindful of the clover setting seed.
Paul says this is an integral component of the dry-sowing cereals strategy.
“The additional annual ryegrass and weeds stimulated by cultivation can then be controlled by a ‘hay freezing’ technique – using glyphosate or paraquat – after the clover has set seed in later spring,” he says.
“That way, the legume seed set component of the system is protected and the grass weeds are almost 100 per cent controlled, which is what we want for the cropping phase.”
Bryan says the plan for this year is to leave the improved pasture in the Grain & Graze 3 trial and set it up for a short-term cropping program in 2016.
He says the pasture benefits of the first two years will hopefully produce higher crop yields in the third year.
DAFWA research officer Perry Dolling is monitoring the Kilpatricks’ trial for amount and timing of nitrogen applications, pasture growth rates, dry-matter production per millimetre of rain and number of grazing days.
The Muchas Gracias group also runs a blog (for members only), which allows sharing of wide-ranging discussions, observations, photographs and trial results.
More information:Bryan Kilpatrick,
0404 082 460,
0427 728 566,
To hear more about the GRDC-funded Grain & Graze 3 trials at the Kilpatricks’ Wagin farm: www.grdc.com.au/GC114V-GrainAndGrazeWagin
GRDC Project Code FG100010