2020 Pasture Variety Trials Results

India Warren-Hicks, South East Agronomy Research

In 2020, Meat and Livestock Australia and ASHEEP commenced a Pasture Variety Trial Producer Demonstration Site project, working in collaboration with the team at South East Agronomy Research and local agronomist Theo Oorschot (Esperance Rural Supplies). The trial’s objective is to demonstrate the most productive pasture varieties for various soil types and environments.

The project includes five years of trials between 2020 - 2024. The first two years are plot-scale demonstration sites, followed by three years of commercial scale demonstration sites.

2020 saw three sites selected: Salmon Gums, Grass Patch and Neridup. Details of the 2020 trial sites can be seen below.

Grass Patch

In 2020 Grass Patch was the standout trial of the three. Prior to sowing, soil cores were taken across the trial site and the subsequent results highlighted both good nutrition and soil structure; reflective of the clay/loam soil type. The results demonstrated high levels of N, P, K and S at the surface to 30cm. Considering the dry start and some soil variability throughout the site, the trial emerged well. By mid July 90% of the trial was established. The Brassica, Cereals and Ryegrass were standouts for early establishment and growth. The Clovers, Biserrula and Lucerne were slow to establish and struggled to outcompete the background Medic. As the season progressed the Medic began to take over the slower establishing species.

On the 12th of June, 10 weeks after sowing (WAS), pasture cuts were taken of each species to compare dry weights. At this stage the Clovers, Biserrula and Lucerne were still emerging. At 10WAS the Brassica was the standout with 830kg/ha of dry matter, followed by Barley with 590kg/ha. At 17WAS the second cuts were taken and the Barley, Ryegrass and Brassica continued as the standouts. These were closely followed by the Wheat, Vetch and Biserrula that had put on good biomass and subsequent dry matter since the previous cut.

On the 19th of August, the ASHEEP winter field walk was held with a great turnout and response from attendees on the Grass Patch trial site. Unfortunately, at this point the other two sites were not visited on the day and a progress update was delivered  instead. Following the field day the Grass Patch trial site was grazed. The grazing demonstrated sheep preference, with the Brassica being grazed last. It was suggested by Dave Vandenberghe that a mow may have been more beneficial than a graze in the future to prevent trampling.

Neridup (Sandplain)

The Sandplain site is situated 35km East of Esperance. The soil tests are reflective of deeper sands in the high rainfall zone with low levels of N, P and K at the surface down to depth. This is due to the low clay content and high leaching nature of sand. Due to the non-wetting soil type sowing was held off waiting for a good rain and the trial was eventually sown on the 11th of May. The trial established well however multiple damaging wind events blew most of the trial and resulted in poor pasture survival, growth and competition. In return the trial had a very high weed pressure. From early on other than the cereal plots weeds took over majority of the trial, namely Capeweed and Silver Grass. On the 12th of July pasture cuts of varieties that had outcompeted weeds were cut. Due to paddock hygiene concerns the site was sprayed out. The trial was resown into moisture on the 6th of August. With this very late time of sowing other than Panic the trial established and grew biomass well. The Brassica got going early however Diamond Back Moth pressure was so high all plots eventually died. The field walk on the 8th of October had a surprisingly good turnout. It was also filmed to reach more members that could not make the day. The response was very positive with growers interested with what grew well at such a late sowing. The Ryegrass, Medic and Lucerne were all points of discussion, all with notable growth. Following the field day the trial was mowed to prevent seed set of weeds and clean up the site.

Salmon Gums

The soil tests are reflective of the heavy Mallee soils with good topsoil nutrition running to higher EC/ Sodic soil at depth. The trial was sown dry and sat for 10 weeks, only emerging by mid-June. Due to another year of drought and unfortunately a very poor establishment no pasture cuts and minimal monitoring occurred on this trial. A final inspection in mid-August showed Vetch, Wheat, Barley and Ryegrass with the best establishment and growth considering the tough growing conditions.

MLA Stocking Rate Calculator

One of the relevant tools that we are seeking to demonstrate in this project is MLA's free online stocking rate calculator for cows and sheep that may be a tool of interest. By filling in paddock size, pasture available at the start of grazing (kg DM/ha), pasture available at the end of grazing (kg DM/ha), pasture growth rate (kg DM/ha/day), number of days grazing and the pasture allowance (kg DM/ head/ day) you are provided with stocking rate numbers.  

Access the tool via https://www.mla.com.au/extension-training-and-tools/tools-calculators/stocking-rate-calculator/

Below is a screenshot of the website with a pasture situation filled in.

2021 Update

2021 brings the second year of the project with greater knowledge and insight from the first year of trials. With this learning has come some variation to the project moving forward.

Originally in year 2 all trials were to be half cropped to a cereal and half left bare to monitor regeneration the second year. The whole Grass Patch site from 2020 will be cropped due to limited seed set. This decision is also as a preventative measure against high weed burden and management issues for the grower in the future. The site will be monitored to see what regenerates in year 3. The Neridup site is set to follow this plan, awaiting confirmation from MLA. Any further monitoring of the Salmon Gums 2020 site will not occur as no regeneration is expected due to drought conditions.

The Grass Patch and Neridup sites will remain on the same properties but in slightly different locations. The Grass Patch site will be moved to a location with less background Medic. The Sandplain site is moving to clayed country in the hope for a better trial establishment and to prevent the trial blowing. There will not be a trial in Salmon Gums in 2021 with it moving to Simeon Roberts property in Cascade. The producer of the year 1 Salmon Gums site, like many in the area have gone out of livestock due to extended dry and challenging conditions. Despite this move of site, the trial outcomes of Cascade will still be relative to the producers in the Salmon Gums area.

There have been alterations to the pasture varieties being trialled in sites for year 2, as these are confirmed ASHEEP will update its members. In the first year Planet Barley was in all three trials. Being susceptible to Spot Type Net Blotch as the season progressed it was seen across all trials. This year a foliar application will be included to prevent such disease occurring throughout the trials.