Grains Research and Development

Date: 29.06.2015

Raised beds exemplify on-farm adaptation

Author: Clarisa Collis

Image of growers gathered in a field

A Southern Farming Systems raised bed cropping field day in Lismore, Victoria.

PHOTO: Brad Collis

Image of Bruce Wilson

Winchelsea grower and raised beds early-adopter Bruce Wilson is still finding ways to refine the system.

PHOTO: Clarisa Collis

Image of Lachie Wilson

Lachie Wilson prepares to sow grain crops on two-metre raised beds using the family’s new 12m seeder this winter cereal growing season.

PHOTO: Clarisa Collis

Australia famously rode to prosperity on the sheep’s back, but it was the decline in wool as the nation’s main rural export that led to more profitable, risk-averse farming systems in the high-rainfall zone (HRZ).

One consequence was major expansion in high-rainfall cropping about 20 years ago, aided by water-management innovations such as raised beds.

Raised-bed cropping pioneer Bruce Wilson says the land-forming tactic to help overcome waterlogging on heavy clay soils during the long, cool growing season was pivotal to the HRZ grains expansion.

Bruce, whose family farms at Winchelsea, 115 kilometres south-west of Melbourne, says the transition to two-metre-wide raised beds on their property in 1997 lifted grain yields by up to 50 per cent. This allowed them to progressively expand their mixed farming operation from 1000 to 5000 hectares.

Parallel to this growth in the Wilson farm business, raised-bed cropping across Victoria’s south-west increased from 3000ha in 1997 to about 35,000ha in 2003.

Further expansion was interrupted by dry conditions at the start of the millennium, but a return to wetter seasons in recent years has seen a resurgence in new 2 and 3m raised beds and the renovation of old beds.

The Wilsons are a case study in adaptability – moving in and out of raised-bed cropping as seasonal and soil-quality needs dictate.

“In 2014, we created raised beds on another 100ha, mostly to improve soil structure,” Bruce says, adding that raised beds now cover about 1500ha of their 3000ha grains program.

He says another benefit of the raised-bed revolution on their grey vertisol soils, and in the HRZ generally, is that it has lent itself to new best-practice farming methods. For the Wilsons, these include controlled-traffic farming (CTF), minimum tillage and stubble retention.

Bruce says such beneficial strategies linked to the implementation of raised beds have posed new challenges that have also driven adaptation and innovation in farm machinery design. For example, 2m raised beds encourage the principles of CTF across the family’s paddocks because machinery wheels are confined to the furrows separating the beds.

The result is reduced soil compaction that improves soil properties. In addition to increasing yield potential, better soil has resulted in faster vegetative growth that leads to heavy stubble loads.

Bruce says sowing into large stubble loads with discs is not an option on their grey clay soils, so in the past they resorted to burning despite their preference for stubble retention.

Now an ingenious advance in on-farm machinery development has helped the Wilsons to overcome not only the problem of high stubble loads, but also raised-bed renovation, slug control and subsoil manuring.

This development is a custom-made K-Line Agriculture machine featuring discs to cut the stubble and work the soil, furrowers to form the beds and a roller that flattens the raised bed surface and crushes slugs.

“Hydraulics on the furrowers mean they can be disengaged and lifted out of the way, so the machine can be used to incorporate stubble and our mix of pig manure, lime and gypsum as well,” Bruce says. “Plus it can be used on our bedless canola country.”

Investing about $140,000 in the machine, Bruce thinks they might recoup this expenditure in less than two years.

This projection is based on his estimate that its multi-functioning benefits have the potential to lift the profitability of their grain crops by about $100/ha.

More information:

Bruce Wilson,
0417 587 387, 03 5267 2381,
bruce@murdeduke.com.au 

Raised beds had a floral start

By Clarisa Collis

Helping to lay the foundation for raised-bed cropping in Victoria’s high-rainfall zone (HRZ), Bruce Wilson says this crucial system for handling wet soils and enabling grain growing in these regions stems from modest beginnings.

Image of raised beds

Raised beds ready for sowing near Lismore, Victoria. From modest experiments, raised beds have contributed to a cropping revolution in high-rainfall zones.

PHOTO: Brad Collis

Bruce says grower confidence in the raised-bed concept was drawn from lessons learnt in Geelong at South Roxby on former agricultural land where Southern Farming Systems (SFS) established its first trial site.

There, just 25 kilometres south-west of the Geelong CBD, SFS tested the efficacy of the raised-bed concept in the organisation’s second year in 1997.

Adopting agronomy and equipment from cut-flower and vegetable cultivation operations, which were using raised beds at Werribee, Victoria, SFS trialled wheat on beds at two widths – two and 20 metres.

“The trial results were spectacular,” Bruce recalls.

“Wheat on the 2m raised beds yielded about 50 per cent more grain compared with the flat control plots.

“The plants developed an extra two to three tillers, and an extra six to eight seeds in the seed heads. Apart from the yield gain, root development was also extraordinary because the soil in the beds was more friable and aerobic.”

Wheat yields were found to increase slightly on the 20m raised beds; however, the plants matured unevenly, were difficult to harvest and the wider beds were more expensive to form, Bruce says.

The trial further showed that the 20m raised beds, resembling a ‘hump in a hollow’ also lacked the soil improvement benefits of the 2m raised beds.

Seeing these results firsthand, Bruce was one of six Victorian growers encouraged to introduce raised beds on their own grey, sodic, vertisol soils.

Each of these growers aimed to trial raised beds across 10 hectares of their properties, but Bruce says the SFS research findings spurred him to introduce them over 30ha.

To achieve this aim, they cobbled together different farm machines, mostly power-driven rotary harrows, he says.

“One grower dragged a log behind a levelling machine to create furrows across his paddocks.”

Bruce says the barley seeded on their first raised beds yielded on average about 30 per cent more grain than bedless flat country.

“This result gave us the confidence to expand our grain crops on raised beds over 1200ha of owned and leased grazing country in the following three years.”

Today, raised beds cover about half of the Wilson family’s 3000ha cropping program.

More information:

Southern Farming Systems

Next:

Nutrition management reflects measured thinking

Previous:

Research looks to arrest escaping nitrogen

Region South