A short video (uploaded Mar 31, 2016) describing Western Australian research into managing subsoil acidity in the wheat belt. DAFWA soil scientist Chris Gazy and UWA research officer Paul Damon describe five-year field trials started in 2015 (sites: South Doodlakine and Merredin Research Station) and accompanying glasshouse experiments testing lime and 13 alternative products. Goals include incorporating lime to depth via strategic tillage, reducing lime rate while increasing effectiveness, assessing calcium nitrate with lime, measuring yield responses (up to ~13% reported), and modelling long-term economic benefits under the GRDC-funded Soil Constraints West initiative.
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WA researchers are taking the next quantum leap to uncover new ways of tackling subsoil acidity. For more than 20 years, work carried out by the Department of Agriculture and Food, Western Australia has highlighted the benefits of top dressing lime to improve the PH of wheat belt soils, DAFWA soil scientist Chris Gazy says incorporating lime to depth with cultivation is also proving to help overcome subsoil acidity constraints to crops and improve wheat yields by up to 13%, he says the next step is to look at the effectiveness and economics of strategic tillage options, organic amendments and novel products for subsurface amelioration. The research will be carried out in the next five years through the Grains Research Development Corporation's Soil Constraints west initiative. In collaboration with DAFWA and the University of Western Australia, we've set up two.
Field trials in 2015 2015, one at South Doodle Kine in the eastern wheat belt and one a bit further east at Meriden Research Station. These trials have been set up to last five years of the project and the main aim is to look at how much can we reduce the acidifying effect of our fertilisers. And the main treatment is calcium nitrate in conjunction with lime treatments as well. This new project will fit nicely with the other soils projects that form part of the Soil Constraints west initiative. One of the main aims that we want to do from these groups of projects is to maximise the multiple benefits that are available to growers when they treat one of the constraints. Perhaps they can be adding towards the treatment of another constraint as well. An example would be under controlled traffic farming systems if they deep, rip and incorporate lime at the same time. We're getting rid of compaction, we're maintaining the soft soil and we're treating acidity at the same time.
Chris says one of the main aims is to cut the amount of lime required by growers, but to get a bigger return from the lime that is applied.
We want to make the treatment of soil acidity more affordable and more attractive to growers. One of the things that has to be remembered is that by treating soil acidity you're actually recovering the soil and achieving the potential yield that you should be able to get. One of the things that's not usually recognised is the losses that are caused by soil acidification or low soil ph to try and work out the economics of the treatment options. Firstly, we've got obviously yield differences and responses to the treatments that we put in and we understand the costs of those various treatments. But the thing to remember is that treating acidity is something that is long term and these benefits are going to last long term or they're going to need to be supplemented and managed over a long period of time. And we'll use modelling, economic modelling and things to take all of that into account.
As part of this research, Glasshouse studies are being undertaken at UWA to look in more detail at alternative line products. As explained by University research officer Paul Damon in 2015.
We've conducted a Glasshouse experiment looking at 13 different new products for managing subsoil acidity and we're comparing them with doing nothing or with conventional treatments such as lime sand or crushed lime or dolomitic lime, to see how they hold up in increasing plant root growth into acidic subsoils and managing subsoil acidity. We don't want to look at anything that's not practical or viable or economical, so all of the treatments that we are testing should hold up in an economic and practical sense.
Paul explains what's going to happen with this research in 2016 and beyond.
We're going to take a few of the most promising looking treatments, we're going to test them further, we're going to try different soil types, larger pots and longer duration of experiments and try and look at where and when the products are likely to be most effective by understanding how and why they work.
