Soil amelioration trials conducted at Lubeck and Netherby in the Wimmera are showing applying nutrients as either duck manure or fertiliser plus deep ripping increased wheat yields in the season following application. BCG, with funding through the National Landcare Program and support from the Wimmera Catchment Management Authority, will soon commence the third year of these trails.
BCG Research Agronomist Kate Maddern said: “Through these trials we hope to gain a better understanding of these techniques on yield, especially given the expensive upfront costs.”
Deep ripping can be used to ameliorate soils that have hard pans or compacted layers that are currently restricting crop root growth. By mechanically breaking up the hard soil, it allows the crop roots to grow deeper, potentially increasing access to moisture and nutrition. “For deep ripping to have an effect,” Ms Maddern said “the tynes must be able to penetrate below the compacted layer”.
Ms Maddern stressed however the differing results in different soil types and the importance of addressing other soil constraints first as well as testing for soil constraints such as soil sodicity, acidity or salinity to ensure they are not brought to the surface.
“Yield responses to deep ripping are most likely to be seen on soils that are only constrained by compaction or hard pans, and other soil constraints need to be addressed prior to deep ripping,” Ms Maddern said.
These trials have generated much interest from farmers eager to learn whether the benefits of deep ripping on deep sands in the Victorian Mallee will translate in the northern Wimmera region. These trials are also investigating whether deep ripping sandy soils with a clay layer (duplex soils) provide a benefit and whether clay spreading ameliorates non-wetting sands.
Ms Maddern said claying results to date have not been as promising: “The trials have shown claying decreased yields, potentially due to difficulties in incorporating it on a plot scale. Establishing a crop on ripped or clayed soil can be difficult due to variable seeding depth however crop type and seeder set up can be used to improve establishment.”
This year’s trials
Ms Maddern is looking forward to getting this year’s trials in the ground, which are looking at the effects and responses of these treatments long term, in the ground by mid-May and analysing the results come December.“We will be sowing Spartacus barley this year at both the Netherby and Lubeck sites. It will be interesting to see whether the amazing response we had with manure in the first year at Netherby will continue and what the impacts of deep ripping in the Wimmera at Lubeck will be in the trial’s third year.”
For more information on this trial call Research Agronomist Kate Maddern on 0458 950 394.
This trial is supported by Wimmera Catchment Management Authority through funding from the Australian Government’s National Landcare Program. We thank the Taylor family and RobCo Rainbow for hosting these trials.
Image caption: Differences in root growth between not ripped (three on left) and ripped (three on right) treatments in chickpeas at Netherby 2/9/2020. 40cm ruler for scale.