Ripping to combat compaction, non-wetting soils

The once frowned upon tool is making something of a comeback joining spading and mouldboarding as a management practice to combat non-wetting soils or break hard pans and invert resistant weed seed populations.

Morawa, WA farmer Grant Borgward, who distributes the Czech Republic-made Terraland chisel plough argues it is a timely introduction.

“Our soils in WA have never been as compacted since the start of no-till farming,” he said.  

“We have faithfully adhered to the practice and while nobody can dispute the benefits, the unintended consequence of no-till in combination with heavier machinery is the creation of soil hard pans in the top 75mm to 125mm.

“Paddock preparation mainly is a forgotten art because of the lock-on to one-pass crop establishment which was always promoted as eliminating wind erosion and retaining moisture in the soil.

“But the soil itself was never a headline act and years of no-till sees us now looking at about 90 per cent of our [WA] Wheatbelt soils that need hard pans broken at this depth, along with hard pans that are forming at deeper depths, because we have kept moving to bigger machinery to increase productivity and profitability.

“If you dig a soil pit and look at the profile, typically you’ll see a shallow grey band in the top 75-125mm which indicates the soil is alive,” Mr Borgward said.

“Below that the soil is sterile because there’s no oxygen and soil pH is low.”

He said the adoption of a no-till regime had also seen poor lime amelioration when attempting to elevate soil pH.

“What we know now is that the introduction of spading triggered alarm bells that lime needs to be properly incorporated because on many properties, a 10 to 15 year liming program, for example, might see as much as a 50pc still inert.

“It’s not surprising we have moved on recommended rates from 1t/ha to 2t/ha or more.”

The latter rate is what Mr Borgward uses on his Morawa farm and is a perfect introduction to the working of the Terraland.

“We spread the lime in front of the Terraland and incorporate the lime along with the inert lime and in the first year we get a very big response,” he said.

“Soil tests show we get an average 0.4pc rise in soil pH at a depth of 600mm with an average 0.56pc lift between the soil surface and 600mm, which shows us the lime is getting down into the soil profile.”

But it is not only about elevating soil pH.

Using the Terraland is making nutrients available to plants

For example, trials on the Eradu sandplain to test for potassium (K) availability were constructed every 100mm to a depth of 600mm.

Testing before using the Terraland showed average levels of K were 23.5 parts per million (ppm) and after use averaged 53.3ppm. 

The amount of phosphorous (P) availability also increased by 14.5ppm.

Subsequent oxygenation played a major role in nutrient availability to plant roots.

The obvious conclusion to increasing plant availability of nutrients is not only crop yield benefits but a bigger subsoil biomass, which in the presence of moisture (oxygen) oxidises and breaks down to form soil humus.

“Every farmer’ goal should be to get roots down to the tilling depth in the year the soil is being tilled,” Mr Borgward said.

“Doing so achieves a better structured soil that becomes more resilient to compaction pressures.

“This is important because with land becoming more expensive and cost of production showing no signs of slowing, the old concept of growing more on what you’ve got is gaining a lot of credence.

“And I think with the Terraland, you’re accelerating that concept while maintaining a one-pass crop establishment with a precision seeder like the DBS,” he said.

“It’s a progressive thing because some soils you’ll initially leave alone, like ones characterised by hostile subsoils or too sodic or dome or cheesey clays.

“But the majority of WA soils, probably 85pc, are a goldmine of nitrogen (N), P and K which can become plant available with strategic deep tillage, soil renovation and ameliorating lime at depth.    

“You can handle the other 15pc using the Terraland, with a different program specific to your environment.”

According to Mr Borgward, using the Terraland can be a slow operation.

“Typically on a 10 hour shift you’ll do 50 hectares, depending on conditions,” he said.  

“So two shifts gives you 100ha a day with a residual between five and 10 years, depending on soil type.

“But I would confidently say it is the only ripper on the market that mixes the subsoil with the top soil and oxygenates the worked soil profile.”

The Terraland is a trailed chisel plough for intensive tillage depths of up to 60cm on a six metre working width with tine spacings set at 430mm.

The Terraland TO model comprises two rows of heavy duty tines with carbide, hard-faced chisel points fitted below a wing assembly.

A following tandem spiky roller completes the incorporation while leveling.

The central frame is formed by four-girders and the frames of working sections are made of 150×150mm RHS.

A rear drawbar means Bednar Cutterpack or Presspack trailed packers can be connected.

According to Bednar, the Terraland is designed to bring the sub soil, which is richer in clay and nutrients, to the surface while ripping the deep profile.

The Terraland tine is matched with a range of blade widths from 40mm to 125mm with the option of delving blades which can be adjusted for the amount of mixing needed.

“The shape of the tine and the mixing wings on either side of the tine ensures thorough mixing of the soil beneath the surface,” Mr Borgward said.

“And the giant tandem spikey rollers mix the topsoil and pack it down firm to lock in the moisture and level the paddock for a seed bed.

“We call the Terraland’s action renovation tillage because we are improving so many of the soil attributes in just one pass.”