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Crop establishment: A key focus for Cuballing farmer, Shaun Wittwer

Shaun introduced a 2012 Ausplow Multistream with a DBS seeder bar to his enterprise.
Photo: GRDC


Grower: Shaun Wittwer
Location: Stratherne Road, Cuballing
Cropping area
: 5000ha
Livestock: 12000 head/sheep
Crop types: Wheat, barley, oats, canola
Soil type/s: Primarily loam over clay
Rainfall zone: Medium
Seeding equipment: 15m Ausplow DBS seeder bar with single 25mm (10-inch) spacing, Ausplow Multistream air cart, consisting of four bins, an integrated tank and liquid dispensing.

Optimising crop establishment is of key importance to Cuballing grower Shaun Wittwer. Seasonal variability and a range of soil types throughout his farming enterprise make achieving consistent crop germination a challenge.

Shaun has hosted trial sites along with the Facey Group to investigate the impact of seeding depth and sowing rate on canola establishment. He has also trialled various management strategies to pinpoint and fine tune the tactics that work well on his property across various crop types.

Shaun considers reduced weed competition and grain yield maximisation to be the key benefits achieved through increased crop germination. Soil moisture at seeding, germination rate and uniformity, rainfall, flowering window, incidence of weather extremes and market prices are all factors that determine the success and profitability of a cropping program, according to Shaun.

Management to improve crop establishment

Shaun's DBS seeder bar.
Shaun's DBS seeder bar.

Management strategies employed by Shaun to improve crop establishment rates include summer weed control, minimum tillage, wetter trialling and recently the introduction of modified one-way ploughing (Plozza Plow), particularly on the non-wetting areas of the property.

The greatest challenge to crop establishment on Shaun’s property is the lack of early rainfall events above 15 millimetres and subsequent water repellence. Shaun finds stubble retention and deferred seeding strategies useful in reducing the impact of water repellency.

Shaun places some importance on canola seed size, stating that the larger seeds provide better results on his property. However, a target seed size of about 2mm is unrealistic according to Shaun, as there would be an inadequate quantity of seed grown each year that meets this size specification.

Shaun’s wife Hilary, who has an agronomy background, determines the ideal sowing rate, which has been of significant benefit in improving crop establishment for their enterprise.

Time of sowing is determined primarily by flowering window to reduce frost risk. In 2021, there has been an opportunity to sow Illabo wheat, other cereals and pasture early for stock feed due to late summer/early autumn rain providing adequate soil moisture.


Constraints to crop establishment on Shaun’s property include soil-borne pathogens, particularly Rhizoctonia, as well as nematodes. Even when implementing a rotation of pasture, cereal, cereal, pasture, Shaun notices that the number of pathogens is still problematic. Strategic tillage has been found to reduce the impact of these constraints.


With a focus on increasing crop germination, Shaun introduced a 2012 Ausplow Multistream with a DBS seeder bar to his enterprise. The key feature of interest was the break out pressure that would allow him to dig into the dry, heavy areas of his property.

Shaun's air cart.
Shaun's air cart, consisting of four bins, an integrated tank and liquid dispensing capabilities.

Shaun reported that the DBS system has allowed him to achieve consistent seeding depth, which has improved crop germination noticeably across his enterprise.

The air cart has four bins, which are sealed and pressurised. It has liquid dispensing capabilities, with an integrated tank. It has a proportional hydraulic metering system, that feeds into two primary lines. Shaun rates the metering system as having excellent suitability for small seeds such as canola and good suitability for coarser seeds.

The in-cab control system is a TopCon X20. “It has good row to row distribution accuracy and metering accuracy at low seed rates,” Shaun says.

Shaun trialled some modifications to his airseeder set up, including split row seeding, wider press wheels and a wider closing tool. However, these modifications did not result in consistent germination so Shaun reverted back to single 25mm (10-inch) spacing.

A challenge that Shaun currently faces relates to the defined furrows created by the DBS bar, which are prone to filling and subsequent seed burial during strong wind.

DBS seeder bar.
Close up of the knife point configuration of the DBS seeder bar. In future, Shaun will look to incorporate soil wetter distribution.

Pre-seeding checks

Seeding depth is monitored daily by Shaun, and adjustments are made in relation to crop type, soil condition and moisture. Fertiliser is banded deep away from the seed, and is monitored visually to check correct placement.

Top tip for plant establishment

Shaun believes there is no ‘one size fits all’ approach to optimising crop establishment, and the best strategy is for individual growers to determine what works best in their system and across their soil types.

Future direction

Looking forward, Shaun is keen to see how the one-way ploughing impacts on crop germination on his property and is aiming to incorporate soil wetters into the seeder bar to inject soil wetter in furrow. He is also interested in further research into soil amelioration in gravel and sandy soils.

More information: Shaun Wittwer, 0428 887 869,

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