Deep ripping, 'deeper' deep ripping and water use efficiency

2016

Research organisaton
Funding source

Trial details

Researcher(s) Debbie Gillam and Laura Dorman (MIG)
Year(s) 2016
Contributor Mingenew-Irwin Group
Trial location(s) Site 9, Mingenew, WA
Deep ripping, 'deeper' deep ripping and water use efficiency locations
Aims
  • OBJECTIVE 1: For growers, researchers and advisers to have a better understanding of the costs and benefits of ‘deeper’ deep ripping versus standard deep ripping and in particular depth of deep ripping required to optimise crop yield and profit.
  • OBJECTIVE 2: To gain a better understanding of whether the higher cost associated with deeper ripping is matched with a corresponding yield increase taking into account the rainfall zones and the soil type.
  • OBJECTIVE 3: Assess how long the benefits of ‘deeper’ deep ripping benefit last in a CTF system.
  • OBJECTIVE 4: Enable growers and advisors on behalf of their clients, assess the cost-benefit of undertaking ‘deeper’ deep ripping.
Key messages

Sub-soil compaction, caused primarily by the unmanaged movement of heavy machinery, is having a negative effect on grain yield and quality across the Geraldton Port Zone (as well other port zones in WA).  Compaction limits plant root growth, reduces plant available water capacity (PAWC) and in turn limits yield potential.

The profitability of a crop is dependent on the crop maximising the use of rainfall received and the PAWC of the soil is critical to this. This applies to all rainfall zones. Climate change however, has influenced the number of dry periods occurring during the growing season, so it’s more important than ever for crop roots to be able to explore the soil profile to the fullest possible extent.

Growers report that some soils on their property continue to underperform despite their fertiliser and system management strategy matching their soil type. The introduction of deeper deep-rippers to the region (550 – 700mm) has shown encouraging results, prompting growers to question current strategies and investigate the rippers as options for soil improvement.

In 2016 four growers within a 100km of each other currently employing deeper ripping strategies were asked to compare the performance of ‘deeper’ deep ripping (550-700mm) to standard deep ripping (250 – 350mm) and no ripping.  A full soil, plant tissue and grain yield analysis was performed at each site to gather information on the base site parameters and breakdown of how each soil responded to the treatments.

There was an increasing response to deeper ripping associated with a decline in rainfall at the sites (about 100mm variance across sites). To achieve the best return on investment growers are recommended to identify the sub soil constraints in their paddock before choosing the right tillage machine to alleviate them.

Lead research organisation Mingenew-Irwin Group
Host research organisation N/A
Trial funding source GRDC
Related program Deep Ripping, Deeper Deep Ripping & Water Use Efficiency
Acknowledgments
  • Many thanks to the Cosgrove, Blake, Brindal and Preston families for implementing the trials and assisting with this research.
  • This research is part of the GRDC funded project “Deep Ripping, Deeper Deep Ripping & Water Use Efficiency”
  • Many Thanks to Stephen Davies and Bindi Isbister, DAFWA, for their assistance and support of this research.

Other trial partners Not specified
Download the trial report to view additional trial information

Method

Crop type
Treatment type(s)
  • Soil: Compaction
Trial type Experimental
Trial design Replicated

Mingenew 2016

Sowing machinery

Four growers using deeper rippers in 2016 were selected for participation in this research based on their soil type and the tillage equipment being used by them.

The soil types included: 2 white sand sites, a yellow sandplain and a gravel soil. Each soil was sampled and analysed to a depth of 800mm. The information from analysis was used for soil characterisation including soil moisture characterisation.

Growers were required to replicate each tillage treatments and include strips in their paddock with no tillage for comparison. Deeper ripping is the new innovation being tested in this research and growers were required to be using an implement capable of ripping to between 550-700mm. Each grower also included replicated strips using a standard ripper (250-350mm). All ripping treatments were implemented prior to seeding.

Soil moisture probes were installed at three of the sites in the nil treatment. Due to soil&

Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Download the trial report to view additional method/treatment information
Trial source data and summary not available
Check the trial report PDF for trial results.
Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Site 9, Mingenew, WA Not specified
Derived trial site soil information
Australian Soil Classification Source
Trial site Soil order
Site 9, Mingenew, WA Chromosol
National soil grid Source
NOTE: National Soil Grid data is aggregated information for background information on the wider area
Actual soil values can vary significantly in a small area and the trial soil tests are the most relevant data where available

Soil properties

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Climate

Site 9, Mingenew WA 2016


Observed climate information

Rainfall avg ann (mm) 400mm
Rainfall avg gsr (mm) 350mm
Rainfall trial total (mm) 450mm
Rainfall trial gsr (mm) 400mm

Derived climate information

Site 9, Mingenew WA

CAUTION: Trial site locality unknown; Climate data sourced from Mingenew-Irwin Group office location
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Some data on this site is sourced from the Bureau of Meteorology

SILO weather estimates sourced from https://www.longpaddock.qld.gov.au/silo/
Jeffrey, S.J., Carter, J.O., Moodie, K.B. and Beswick, A.R. (2001). Using spatial interpolation to construct a comprehensive archive of Australian climate data , Environmental Modelling and Software, Vol 16/4, pp 309-330. DOI: 10.1016/S1364-8152(01)00008-1.