trials

Why do the trial? 
Barley grass possesses several biological traits that make it difficult for growers to manage it in the low rainfall zone, so it is not surprising that it is becoming more prevalent in field crops in SA and WA. A survey by Llewellyn et al. (2015) showed that barley grass has now made its way into the top 1 O weeds of Australian cropping in terms of area infested, crop yield loss and revenue loss. 
The biological traits that make barley grass difficult for growers to manage in low rainfall zones include: 

- early onset of seed production, which reduces effectiveness of crop-topping or spray-topping in pastures,
shedding seeds well before crop harvest, reducing harvest weed seed control effectiveness compared to weeds such as ryegrass which has a much higher seed retention,•    increased seed dormancy, reducing weed control from knockdown herbicides due to delayed emergence, and
•    increasing herbicide resistance, especially to Group A herbicides, used to control grass weeds in pasture phase and legume crops. 

Barley grass management is likely to be more challenging in the low rainfall zone because the growing seasons tend to be more variable in terms of rainfall, which can affect the performance of the pre-emergence herbicides. Furthermore, many growers in these areas tend to have lower budgets for management tactics, and break crops are generally perceived as more risky than cereals. Therefore, wheat and barley tend to be the dominant crops in the low rainfall zone. This project is undertaking coordinated research with farming systems groups across the Southern and Western cropping regions to demonstrate tactics that can be reliably used to improve the management of barley grass. 

Over the past three decades there has been a shift from integrated crop-livestock production to intensive cropping in dry areas, which has significantly reduced the resilience of farms in low to medium rainfall areas. Intensive cropping is prone to herbicide resistant weeds, large nitrogen fertiliser requirements, and major financial shocks due to frost, drought or low grain prices. 
A pilot project with MLA and AWi in WA and southern NSW has demonstrated how novel pasture legumes such as serradella, biserrula and bladder clover can improve livestock production while reducing nitrogen requirements, weeds and diseases for following crops. The extent to which these new legumes establish, grow and persist on South Australia's alkaline sandy soils requires clarification. 
The demonstration sites are primarily an extension tool, unlike research trials requiring detailed data collection. The purpose of these sites is to gather information on regional legume performance, including benefits to the crops that follow. 

This article will report on findings from two pasture trials conducted on the lower Eyre Peninsula in the 2019-2021 growing seasons. The trials are part of the demonstration component of the Dryland Pasture Legume Systems (DLPS) project developed with the former LEADA committee/AIR EP Medium Rainfall RD&E committee to answer several questions about how pasture performance could be improved in the region. 
Demonstration 1: What is the best pasture species/ mix of species to plant in paddocks with differing soil types? 
Background 
Paddocks across the region often have soil types that vary, ie. changing from heavier flats to sandier rises, with pH varying from below 6 to above 8. Getting pasture species established and maintaining good production levels across this landscape is often challenging. 

Trials and demonstrations involving soil mixing either with a spader or ripping with inclusion plates have been shown to increase yields on sandy soils on Eyre Peninsula (EP). Many of these trials have included the addition of organic material incorporated at rates of 5-10 t/ha. Whilst generally these treatments have provided yield increases for a number of years post application, the rates applied have proven to be uneconomic (EPFS 2019, p 71). This project was originally developed by the Lower Eyre Ag
Development Association (LEADA) with two major objectives being:
1. To test ripping with inclusion plates on a wider range of soils.
2. To trial rates and sources of organic matter that are practical for broadacre use.

This article reports a trial at Minnipa which investigated mixed species cover crops grown over winter and their impact on wheat production the following year. 
 

To report on results of a visit by Wayne Hawthorne (esteemed pulse expert from Pulse Australia) to Kangaroo Island.

• To demonstrate the effect of crop canopy densities on pollination.

To investigate the merit of fodder crops in the crop rotation, with particular interest in weed control, nitrogen and gross margin.

• To demonstrate and refine the technique to suit the many mixed farmers on Kangaroo Island.

• To allow producer groups to trial new grazing systems in their local environment at a commercial scale.

• To allow some farmers to see first hand how such crops performed on their own patch of dirt.

• To investigate different responses to the application of single, triple and gold phosphorus fertiliser on pasture growth.

To investigate the questions:

• What if there was a simple way to improve the top soil depth to encourage plants to grow deeper root systems?
• Could we grow the massive crops you seen grown overseas where they measure top soil in feet not inches?

To find crop species suitable to Kangaroo Island conditions, which were either:
• of higher value per tonne than currently grown milling wheat, or
• low yielding yet high value to reduce the per hectare freight cost.

• To conduct pasture trials and assess for plant density, plant size/vigor and basal cover.

• To report on the development of a rhizobium strain which is able to nodulate with lucerne at lower pH.

• To test ProGibb SG for the potential to increase kikuyu production in winter.

• To assess the yield response using honey bees for pollination in dryland faba beans.

Research on the mainland has shown that sowing lentils in the inter-row in wheat stubble encourages the plant to grow taller in pursuit of sunlight, enabling easier harvest for what is normally a short crop. Although broad beans can be a tall crop, the bottom pods contain the largest beans as these set the earliest and thus have the longest time to fill. However, in many cases these large seeded pods are too close to the ground for the harvester to pick up and yet it’s these big beans that are worth the most.

Like the lentil story above, local farmers are curious as to whether the height of the previous year’s wheat stubble may influence the distance from the ground of the first pod. There was also contemplation as to whether the stubble height had an effect on disease incidence in the bean crop.

To report on what has been learnt about growing kikuyu on Kangaroo Island.

• To investigate the potential of kikuyu as a hardy pasture species on Kangaroo Island.

To investigate the usefulness of kikuyu for farmers on Kangaroo Island.

• To investigate the establishment of kikuyu pastures on Kangaroo Island.

To investigate the question of whether kikuyu pastures pay.

To investigate the quality and quantity of kikuyu pastures.

• To compare an existing kikuyu stand to an adjacent paddock of annual pasture.

To report on Landmark pasture trials investigating ESN on annual ryegrass and Awaken ST on ryegrass amongst other treatments.

To investigate the role of the nitrogen stabilisers and plant stimulants on pastures.

To support grower groups to identify and demonstrate the establishment and management of suitable multi species cover crops across a range of environments and assess the impacts of cover cropping on soil health, nutrient cycling, organic carbon, invertebrate populations and soil moisture.

To investigate the idea of Pasture Cropping (PC), which involves seeding a crop into an existing summer-active pasture stand without killing the pasture.

• To investigate posture cropping - involving seeding an annual winter active species (peas) into an existing summer-active perennial pasture stand (kikuyu).

To conduct ground truthing for the Pastures from space program, which provides estimates of pasture growth rate during the growing season by mean of remote sensing.

To assess broad bean root nodulation success.

• To demonstrate how Pastures from Space technologies can be used to increase grazier’s skills in sustainably increasing stocking rates.

To investigate a spader machine for lime incorporation.

The spader trials were set up at several sites ranging from 0.5 ha to whole paddocks. The growers wanted
the spader to incorporate clay, lime and/or organic matter, or just improve the friability of the soil.

To give an indication of performance at different parts of the island.

• To demonstrate growth of a pasture mix consisted of brassicas, chicory and plantain sown in spring, and then bulked up with a short-term Italian rye grass sown the following autumn.

• To test the growth of a range of pasture and fodder species.

This was the second year of a three-year trial, funded by the South Australian Grains Industry Trust (SAGIT), to evaluate the nitrogen fixation capabilities of various legume species commonly grown on Kangaroo Island.

In this second year, the trial was set up to answer the following questions:

• Which of the four legume species had fixed the most nitrogen (N) in the 2016 season?
• How much N did these legume crops fix?
• How much of the N fixed by the legume was utilised by the following crop? Concurrently, how much N was lost through leaching or denitrification?

To evaluate the impact of Septoria tritici blotch on wheat of different resistant ratings and determine yield loss in the MRZ and LRZ of the Southern Australia

To understand the impact of differing wheat stubble loads on the establishment of canola under a range of locally relevant sowing practices.

To evaluate the impact of Septoria tritici blotch on wheat of different resistant ratings and determine yield loss in the MRZ and LRZ of the Southern Australia

To answer the question 'Why are there so many sick crops in the Victorian Southern Mallee in 1995?'

To discuss abiotic stresses of cool season pulses in Australia.

To gain knowledge that will allow the Australian grains industry to maintain productivity by adapting crops and cropping systems to the effects of elevated CO2.

The aim of this trial was to investigate alternative chemicals for the control of ryegrass in wheat; and in broadleaf crops, canola, lentil and field pea.

To demonstrate growth of 10 different crops at the Birchip site.

Trials were conducted by the BCG to evaluate a range of these alternative oilseed options.

To compare the production of different winter pastures and their recovery from grazing.