Results from the West Binnu trial
Comments on the West Binnu Trial
2016 (Year 3)
Unfortunately the trial area was not cropped in 2016 and so we were unable to get any plant data, in particular yield, in relation to the lime incorporation treatments.
However, soil samples were still taken at the end of the year to look at the effect lime incorporation has had after three seasons. There was significant difference in regard to lime treatment all the way down the soil profile. This can be seen to some degree in the nil treatment where the effect of lime has increased the soil pH down to the depth of the midsoil (10-20cm) as seen in Figure 1.
The soil pH samples for the deep delve treatment seem to have given the best result, where lime was successfully incorporated to the greatest depth (30-40cm). The offset and mouldboard also delivered successful incorporation down to 20-30cm (Figure 1). The one way plough improved subsoil pH, but just not to the same extent as the other machines already mentioned.
The soil pH results for the deep rip treatment didn't support the lime rates that were applied. The deep ripper tines did not displace a large amount of soil, nor were they modified to hold open the slot for topsoil burial. It is possible that this result is from unrepresentative sampling at the time of soil collection, but this is hard to say when even the topsoil samples shows lower soil pH on those areas where lime was applied. Soil samples from previous seasons have shown benefit of lime incorporation using a deep ripper so future samples from this trial will be interesting.
Thanks to Rhys Carson for managing the trials at West Binnu; also to DAFWA technical services staff for their assistance and SoilTech for soil sampling.
This project is supported by the Northern Agricultural Catchments Council, through funding from the Australian Government’s National Landcare Programme.
The West Binnu trial is part of the 'Demonstrating principles of ameliorating subsurface pH to improve soil health project' (INNOV–292) delivered in partnership with Northern Agricultural Catchments Council WA (NACC).