Wheatbelt

Productive pastures in the Eastern Wheatbelt

This trial is now complete

Key Messages

  • Hard-seeded varieties, suitable for acid soils, can provide good seed-set and long-term pasture options (within the cropping rotation) if established correctly.
  • Morava vetch out-performed both farmer and agronomist expectations.
  • When sowing a summer fodder crop, it is best to try and plant a few days prior to a large spring rainfall event to ensure even germination.
  • Super Sweet Sudan was planted late in a dry start and had poor and inconsistent germination, however, where germinated did provide food on offer for sheep that was preferentially grazed before weedy grasses.
  • The Rose/Izmir clover mix germinated well but did not supply much food value due to the lack of rainfall throughout the 2017 growing season.
  • Trial Rationale
  • Steps Taken
  • Lessons Learnt
  • Looking Forward

Trial Rationale

Livestock production accounts for a large part of farm business in the low rainfall Eastern Wheatbelt. However, the recent drop in wheat prices, coupled with high livestock prices, are causing landowners to consider improved pasture systems to increase livestock production.

The recent run of dry years has depleted the pasture seedbank and boosted the abundance of weeds such as capeweed and radish, which encouraged farmers Ian and Bec Maddock and Clint Della Bosca, in Moorine Rock to participate in a trial to improve pasture productivity with the Far Eastern Agricultural Region Growers Group (FEAR). FEAR, with the technical support of AgInnovate, became involved through the Grain Research and Development Corporation (GRDC) Grain & Graze project where it recognized the need for improved pasture/fodder management options and establishment skills.

The soils of Moorine Rock are highly acidic, which reduced the number of pasture species options suitable for the trial and the high cost of liming sparked the landholders’ interest to try acid tolerant pastures as a cheaper, faster way to provide pasture feed for livestock. Clint believed that the vetch he was trialling would provide another break-crop option that could also provide grazing in his mixed farming system. GRDC trials reported vetch break-crops increased wheat yields by 30 to 35% while reducing nitrogen fertilisers by 20 to 25% (GRDC 2014).

The objective of the project was to trial the establishment and production of several acid tolerant annual pasture species in the low rainfall region including:

  1. Pasture establishment methods – exploring cost effective establishment techniques; and
  2. Manage grazing to reduce weeds and maximize pasture production.

Steps Taken

Two sites were selected on the Maddocks’ property; 40 ha (A) and 20 ha (B) and one site of 18 ha was selected on the Della Bosca farm.

Property: Maddock

Site A, with a pH (CaCl2) of 4.9 was sown in May 2017 with oats (as a filler), Izmir clover and Hykon Rose clover at the rates of 30 kg/ha, 3 kg/ha and 3 kg/ha respectively. The seeds were mixed at seeding and a 0.6 m2 sample was taken for biomass measurements in late spring 2017. The two clovers were separated with wet and dry weights measured separately.

Site B, also with a pH (CaCl2) of 4.9 was sown in October 2017 with Super Sweet Sudan (SSS) on its own at a rate of 0.5 kg/ha.

Property: Della Bosca

The site on the Della Bosca property was sown in May 2017 with Morava grazing vetch at a rate of 25 kg/ha.

Lessons Learnt

Property: Maddock

Site A
Based on the 0.6 m2 sample, rose clover produced 28 g of wet feed, with a dry weight equivalent of 24.2 g or 400 kg/ha after grazing. Using dry sheep equivalent (DSE) and accessibility estimate (60% bare ground), AgInnovate calculated a biomass total of 1000 kg/ha.

From the same 0.6 m2 sample, the wet weight for Izmir clover was 29 g, or equivalent dry weight of 18.8 g or 310 kg/ha. Total biomass was calculated at 775 kg/ha.

Considering the less than optimal growing conditions, the sowing of this paddock would have increased the seed bank for the following year, resulting in a small amount of grazing value of 200-500 kg/ha. This could be valued at $50-$130/ha where the energy value of feed is $0.02/MJ.

Site B
2017 was marked as one with the lowest growing season rainfalls on record for Moorine Rock. The seeding period (April to June) was below decile 1 and remained below decile 2 until August. Consequently, due to the staggered germination and a lack of summer rain, the SSS failed to germinate consistently across the paddock. Where it did germinate, the plants thrived and provided good green feed for sheep at a time when there was very little alternative feed available (Figure 1). Sowing prior to the October rain, rather than after it, would likely have resulted in a more even germination and improved grazing opportunities. It is important to mention that following some significant February rainfall, a second germination occurred which indicates that the SSS seeds can remain viable in the soil for extended periods. However, this is not ideal for getting even germination across the paddock.

Property: Della Bosca
Dry seeding of the Morava vetch in May resulted in consistent germination and establishment of the trial area (Figure 2). Combined with the wide row spacing, the total feed on offer (FOO), which averages biomass density over a larger area including bare ground, was quite low. Measured feed on offer ranged from 500 to 1000 kg/ha. When the plants are assessed on an accessibility basis (ignoring the bare areas), the sheep would perform at a level equivalent to FOO of approximately 2000 to 2500 kg/ha.

Using Lifetime Wool feed budgets based on an available FOO of 2500 kg for a twin bearing large frame Merino ewe in mid lactation, the potential energy intake per day of that material would be 32 MJ/day compared to her requirement of 30 MJ/day. At this stage of feed availability, she can lactate for twin lambs and grow at 35 g/day. Even when the feed is only equivalent to 1000 kg/ha, the ewe will almost receive maintenance energy. This ewe will eat almost two and a half kg of dry matter per day, which has a total feed value of around $500/ha, where feed is valued at $0.02/MJ. The nutritional value of vetch as a food source is shown in Table 1.

 

Looking Forward

Three pasture options were established as a part of the cropping rotation, but because of poor seasonal conditions, met with varying degrees of success. The project achieved its aim to increase pasture productivity in low rainfall areas through improved acid-tolerant pasture selection, establishment and management. “All three options; annual clovers/medics vetch and summer fodder crops when managed correctly will increase pasture productivity in the area,” said Danielle England of AgInnovate.

Property: Maddock
Site A
Despite the season, the annual pastures produced a good seed set, which will enable good germination in 2018 and beyond. If allowed to set-seed again in 2018, and if managed correctly, this pasture, because of the hard-seededness of the clover varieties, could persist for many years. “I would recommend putting it into a rotation of 2 years crop followed by 2 years pasture,” said Danielle. “Though because it is a small paddock, close to the yards, it is anticipated that it will remain in pasture for the foreseeable future.”

Site B
The SSS did not establish well due to the short spring and late sowing. “Planting late is a common error made when learning to establish summer fodder crops.” Danielle said. Unlike winter crops, which germinate on soil moisture, summer crops tend to require rainfall immediately after sowing to germinate evenly. Once established, it has the capacity to grow despite follow-up rainfall events.

There continues to be the need for further work regarding successful fodder establishment and management in the Eastern Wheatbelt. The farmers with mixed enterprises in the region are supportive of work, which will allow them to increase productivity of both their cropping and livestock programs.

Property: Della Bosca
The ongoing availability of the vetch fodder depends on the stocking rate and pasture growth rates. “We must remember that there is actually only 500-1000 kg of FOO in the paddock. If we assume daily growth rates of 10 kg/ha/day and we leave 300 kg for cover and regeneration post grazing, this feed could support 20 twin bearing ewes/ha for 10 days,” said Danielle.

“If there were better germination and plant growth and average paddock FOO was 2500 kg, the Della Boscas could either double the stocking rate or run sheep on the paddock for twice as long. If the stock run on the paddock were 25 kg weaners from a large Merino bloodline, the energy available from the vetch would allow growth rates of 250 g/hd/day, with protein intake levels not limiting growth. This paddock could support 40 weaners/ha for 10 days or 10 weaners/ha for at least a month depending on plant growth rates and increasing feed intake as animal size increased.”

Mr. Della Bosca will plant vetch again in 2018 as it has proven to be a viable break-crop option in their mixed farming program. It gives the soil nitrogen input as well as an opportunity to control ryegrass. While he did not graze this crop in this trial, it does have the potential to provide lambing feed in short feed supply years.

References

Grains Research and Development Corporation (GRDC). 2014. ‘DAS00059 – Improved vetch varieties for Australian farmers and end-users.’ https://grdc.com.au/research/reports/report?id=1104

Hyder, M. and Young, J. 2005. ‘Lifetime Wool – Dry feed budgeting tool.” http://www.lifetimewool.com.au/pdf/hyder%20young.pdf

Moorine Rock

Project Snapshot

Land Manager
Ian and Rebecca Maddock, Clint Della Bosca
Shire:
Yilgarn
NRM Region:
Wheatbelt
Average Rainfall:
Low - Less than 325mm
Enterprise Mix:
Mixed crop and sheep
System Constraints:
High weed burden, Soil Acidity
Partners:
AgInnovate, FEAR, Wheatbelt NRM
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