Sub Soil Constraints
Timeframe: September 2014 to September 2019
Funding source: Grains Research & Development Corporation, administered through Department of Primary Industries and Regional Development
Project Coordinator: Maddy Wylie.
DPIRD staff: Jeremy Lemon, Glenn McDonald, David Hall
Summary
In the Subsoil Constraints project, FBG worked closely with DPIRD and other groups in the Albany Port Zone to deliver media, coordinate extension activities and provide landowner trial sites and grower feedback to seek better ways of identifying and managing constraints through amelioration and mitigation.
Project overview and outcomes
Subsoil constraints were identified as a major concern for many grower groups of the South Coast and Southern Wheat belt region of WA. They inhibit root development and function and in doing so limit crop growth and production through restricted access to water and nutrients.
As a consequence of these natural and induced conditions, subsoils in WA are inherently prone to acidity, nutrient disorders, low water retention, compaction and alkalinity/boron/salinity alone and in combination. The cost in lost production associated with these subsoil constraints is estimated to exceed $600 million per year.
The activities carried out during the five years of this project were as follows:
2015
Field Investigations. The FBG coordinated four site visits to local farms by DPIRD staff to assess their suitability for sodicity trials. None were selected.
Workshops and site visits: How’s Your Roots Going? Field walk attended by over 50 people at the Harding family farm at Corackerup. Joint event with North Stirlings Pallinup, with another field walk held at Broomehill. Participants looked at a Controlled Traffic Farming (CTF) system put in place by the Hardings, as well as a deep ripping trial and some other proof of concept trials being run by DPIRD.
2016
Field Investigations – sites visited by DPIRD
Stu and Leanne Bee, Jacup
Site was used to investigate single rate gypsum, with ripping to 400mm using inclusion plates. This was a small plot trial.
Season was very wet and trafficability was an issue.
Lawson Grains – Gunnadoo, Jacup
Site investigation was delayed by wet weather. By the time conditions were dry enough, tractors were being used for seeding and not available for DPIRD usage.
Ripping strips closer to Jerramungup were to be monitored, but this option proved not to be viable due to weather in that year. Management change also saw shift in focus.
Workshops and site visits: FBG Spring Field Day: A soil pit was dug at the site of FBG’s Nutrition Trial at Trent and Tina Parson’s farm, 5km south of Jerramungup. Jeremy Lemon spoke about soil health issues, and it was a good opportunity for growers to discuss subsoil constraint issues directly with him
2017
Field Investigations – three sites were suggested to DPIRD for further investigation
Workshops and site visits
Proposed pop-up soil health site visit – did not proceed
Australian Controlled Traffic Farming Association Tour
As part of the southern tour taking place as part of the ACTFA Conference, a site visit was arranged to the Harding DPIRD trial.
Members were able to attend this part of the tour which was attended by an additional 10 farmers from the area.
Spring Field Day
Two soil pits were dug – one at Lawson Grains, Jerry South, and the other at the Keding family farm
Jeremy Lemon gave an insight into the soil issues faced at each site.
DPIRD Trial Site at Corackerup
2018
Farmer Investigations: A growing interest in deep ripping and looking for local results and solutions led to an increasing number of farmers conducting their own on-farm trials, for deep ripping and other strategic tillage options. A couple of these sites were visited as part of the FBG’s Spring Field Day.
Workshops and site visits
Elders Wilchem Field Day, Jacup
Soil pit dug at site deep ripping by DPIRD in 2016.
WANTFA/DPIRD/ACTFA CTF Workshop, Scaddan
Attended by Project Officer – looked at renovated tramlines in CTF systems.
GRDC RCSN Open Forum, Jerramungup
Subsoil priorities were: Non wetting soils; Identifying which soil amelioration technique will return best value for money; Liming; Farming systems to combat erosion
Spring Field Day, Jacup
two soil pits dug at Stu Bee’s (same location as for Elders field walk), as well as at Mick and Mark Lester’s where they had used a DBS deep ripper earlier in the year.
Subsoil constraint discussion led by Glenn McDonald.
2019
Farmer Investigations Multiple on-farm trials for deep ripping, delving, spading, etc. were carried out by farmers in the district, including the ones mentioned above and others.
Workshops and site visits
GRDC Difficult Soils Forum, Jacup
Coordinated by GIWA, this workshop came about due to the RCSN priorities raised by growers attending their feedback sessions.
It has been generally agreed that soils on the South Coast are very challenging and where there are multiple constraints, the well-researched prescriptions can be hard to apply.
Well attended day, with more than 40 farmers and industry in attendance. Soil pits dug at Mick & Mark Lester’s, as well as Lawson Grains, Gunnadoo.
Landmark Subsoil Constraints field visit, Jerramungup
Coordinated by Advisory (now Board) Member, Kyran Brooks, this well-supported day brought together DPIRD researchers from the South Coast, as well as Northern researchers, such as Wayne Parker and Bindi Isbister, to discuss the multiple constraints and difficulties faced by farmers in the area.