Deep ripping with a twist
Yield gains of up to 45 per cent in broadacre crops have been the key driver behind a trial using very deep ripping for Southern Brook farmer Ty Fulwood.
The practice is increasingly being adopted on Wheatbelt farms, but this trial differs because it uses inclusion plates to help bury nutrient and lime rich top soil.
Ty Fulwood’s first experience with deep ripping came through his father, who reported positive results with an Agroplow 20 years ago.
In the last four years he has played around with several soil amelioration tools including mouldboard ploughing, delving, spading and ripping to various depths.
“One of the stand out responses has been very deep ripping to a depth of 700 millimetres with inclusion plates,” Ty Fulwood said.
“From the beginning of the season, the difference was clearly visible.
“Tissue testing revealed nitrogen and potash recovery was nearly double the control and come harvest there was a 25 to 45 per cent yield benefit.”
The initial success prompted Ty Fulwood to apply for a grant through natural resource management group Wheatbelt NRM.
The research, funded by the Australian government’s National Landcare programme, would help test the impact of very deep ripping with inclusion plates on soil health, fertiliser efficiency and productivity.
Wheatbelt NRM’s Jo Wheeler said the trial was about finding a way to overcome soil constraints.
“Deep ripping to a greater depth is one way of overcoming the compaction of soil in the cropping system,” Jo Wheeler said.
“What makes this trial unique is using the inclusion plates to allow lime and nutrient rich topsoil to fall down the soil profile.
“We will determine its success by measuring soil acidity, plant nutrition and biomass, yield and changes in soil compaction.
“We encourage growers to work with us on trials like this because they can access funding and test new concepts with less risk to their bottom line.”
The deep ripper used for the trial was a four metre Gregoire Besson Heliripper with six tynes spaced at 700mm and ripping to a depth of 700mm.
Three trial sites were chosen across the Southern Brook property covering numerous soil types from deep sands to brown loams.
Each site consisted of two header-width sized repetitions of deep ripping with inclusion plates and two controls strips with no treatment.
The inclusion plates attach to the rear of the tyne sitting 20cm below the top soil.
“We think we’re allowing our roots to go deeper and faster into the soil by removing compaction and neutralizing acidity in the subsoil behind each tyne,” Ty Fulwood said.
“We also believe that at 700mm we’re generally reaching a gravel or clay layer which may be holding high levels of nutrition that are only now being accessed by the roots.”
“We’ve already had a positive response, but we’re looking forward to gaining a better understanding of what is happening with the plants and what soil types we should be focusing our investment on.”