Nyabing mixed cropping and sheep producers Trenton and Rachel Browne have learned some valuable lessons from their trial plots on low lying, partially saline country.
With funding support from the South West Catchment Council (SWCC) the Browne’s have just completed a three and a half year trial comparing the Food on Offer (FOO) of Phalaris (Advance AT), Tall Wheat grass (Tyrrel), Balansa clover (Enduro), Persian (Sardi), Bladder clover (Bartolo), Dalkeith and Messina.
The aim of the trial was to find which grasses and clovers were going to persist in the Nyabing or salt environment. The Browne’s are faced with the challenges of large areas of low-lying, salt-affected country which has traditionally seen barley grass dominating pasture growth. With valuable agricultural land under performing, a more productive pasture was required.
In late May 2014, a knockdown of 1.5 L glyphosate, 300 ml chlorpyrifos, 1% SOA and 0.2% LI700 was sprayed, after which the Phalaris and Tall Wheat grass was sown, along with an application of 70% K-Till and 30% Mono-Ammonium Phosphate (MAP) at the rate of 30 kg/ha.
Creating a plot size of 3 ha, three run lines of each pasture were sown, using a 45 ft DBS with discs. Plots ran east-west on a relatively flat landscape, with a solid salt scald at the western end.
With reasonable rain for initial establishment Phalaris showed early promise compared to the Tall Wheat grass and in October the trial was lightly grazed by sheep.
In April 2015, the project was expanded with the addition of Balansa clover, Persian, Bladder clover and Dalkeith clovers. These plots were established in the same way as the Phalaris and Tall Wheat grass in 2014. Sowing rates varied from 10 kg/ha to 25 kg/ha depending on the variety. Seed set was good across all varieties.
May 2016 Messina was sown at 12 kg/ha, with runs of Messina at 3 kg sown with saltland mix at 10 kg hectares (saltland mix comprised of Crimson clover, Persian, Balansa clover and Barrel
medic), and Balansa clover at 5 kg/ha as the control.
Due to numerous severe frost events in spring 2016, seed set was negatively impacted across the board with exception of Dalkeith and Messina. Messina was not as badly affected due to later sowing/flowering. This is reflected in the germination rates and plant density in 2017.
Table: FOO measurements in September 2015 and October 2016 (Kg DM / ha)
Throughout the trial FOO measurements were taken two to four times a year to record the difference in FOO. In June 2014, before project activities had commenced FOO was recorded at
<100 kg DM/ha. By September 2015 growth ranged from 100 kg to 750 kg DM/ha. In October 2016, at the highest point of production FOO ranged from 400 to >3500 kg DM/ha (see Table).
“I was impressed with the comparisons between legume varieties within this trial, notably the ability of them to regenerate in the following years. I learnt a few critical points for when we roll this type of planting out across larger areas. The most poignant being that a varietal mix will be the best to capture the different soil types and rainfall. Some are going to do better than others in certain circumstances. We have a lot of this type of country, and we need to manage if more effectively to get better value and sustainability from it.”
Rachel concluded: “The weed control could have been better prior to sowing, and management at times was challenging due to conflicts with grazing. But that’s what this was about – learning from our mistakes and improving for the future.”
