Snapshot

Grower: The Rethus Family (Geoff and Christine, Luke and Charlene and Tim and Michelle)
Location: Wimmera
Enterprise mix: Grain only since 2000 - zero-till disc seeding, controlled traffic
Crop types: 2000ha wheat, barley, canola, beans, durum, lentils and hay crops
Farm size: 5000ha crop over three properties
Soil type/s: Self-mulching cracking clay and clay-loam soils
Annual rainfall: 400mm
Average GSR: 300mm
Seeding equipment: 24.38m (80 foot) side-shifting NDF frame fitted with 38.1cm (15 inch) spaced double disc openers, all individually downforce-controlled with hydraulic DeltaForce system, using Keeton seed firmers and twin cast closing wheels. Row-by-row seed counting, blockage sensing on each fertiliser tube, and furrow quality monitoring with Smart Firmers. John Deere 1910 tow-behind air cart with section control and Liquid System on tracks. Also fitted with PJ Green mouse baiting system for baiting at sowing.

For the Rethus family, who farm around Horsham, good crop establishment is critical for success.

“If you have poor establishment, you end up with reduced yield and yield is what we get paid for,” Tim Rethus says.

The Wimmera grower currently operates a farming business with his wife Michelle, brother Luke and sister-in-law Charlene, as well as his parents Chris and Geoff.

“Dad has a saying ‘your maximum yield potential is the day you sowed it’ - after that the most important thing is controlling what you can to minimise losses,” Tim says.

The Rethus family’s rules for effective crop establishment:

1. Timeliness.
2. Early, normally dry sowing to take advantage of the opening rain event and warm soils.
3. Seed quality: plump grains deliver higher vigour and higher germination probability.
4. The right variety for the paddock and sowing time (extrapolating NVT trial results as a key guide).
5. Optimum established density (plants per square metre): Conduct your own in-paddock trial strips using precision agriculture (PA) technology.
6. Correct and uniform seed placement: Ensure clean, residue free furrow and good soil-seed contact.
7. Seed dressing and nutrition (insecticides, starter fertiliser, trace elements).
8. Straw management at harvest. Even spread allows the seeder to be set-up to minimise hair-pinning. Disc seeders in thick damp chaff on header trails is not a recipe for success.

Technology

Staying up-to-date with technology is important to the Rethus family and it is also what they enjoy. Prior to coming back to the family farming business, both Tim and his brother Luke worked in the corporate world for more than ten years as chemical and telecommunications engineers, respectively.

“As a former engineer I like to know how things work. It’s about solving the problem by understanding the source of it,” Tim says.

Geoff with previous PP: Geoff Rethus with the John Deere DB60 precision planter which the family dis-adopted in 2019 despite great benefits, due to the complexity and cost involved in getting the singulation right for all crops in their system.

“What I love about farming is there’s always a challenge and the possibility of creating something new to solve the problem.”

His family’s ability to modify and adapt their seeding equipment and technology is testament to this ethos.

“We moved to a disc seeder around 2000 to maintain a nice soil structure around the seed while still having good infiltration of water,” Tim says.

“We wanted the accuracy of depth and control over how the furrow is forming. These two elements make a big difference to plant establishment. The disc system also fitted with where we were going in terms of moisture conservation by retaining stubble.”

He also believes discs work more effectively in tall stubble, than a tyne.

“Tall stubble minimises chaff on the ground that can cause pinning and standing stubble disrupts the wind, which helps retain moisture over summer. Sowing wheat into tall canola stubble is a great mix,” Tim says.

“The stubble acts as a nice, warm blanket for the wheat, protecting it from wind, but letting light through, which helps with establishment and growth.”

Machinery choice and modifications

The Rethus family has made machinery decisions that have been designed to improve plant establishment, including purchasing a precision planter in 2016.

“We had a single disc Daybreak, but we were having trouble with the discs stalling in our increasingly soft soils and it wasn’t doing a clean job placing the seed,” Tim says.

“We had the option to purchase a John Deere DB60 precision planter. The the twin disc opener delivered fantastic seed placement and also further minimised soil disturbance over the single disc.

“We decided however to dis-adopt, due to the complexity involved in getting the singulation right and its cost. It couldn’t do all our crop types like barley and oats which foul the seed singulation discs.

“It was also doubtful that singulation was offering an advantage on our 15-inch row spacing. For canola it did, and seeds were about eight centimetres apart, but in lentils it was 2.5cm and wheat less again.”

This meant they had to use the Daybreak seeder and the precision planter at the same time, which meant the sowing program was faster, but the seeding process was more complicated logistically.

The family now has a high technology seeder, which is essentially a precision planter without singulation.

They had their seeder custom built: a NDF Ag Design 24.38m (80 foot) frame on tracks with Harvest International double discs openers.

“Essentially it is a precision planter with the singulation equipment removed and matched to our standard air seeder system,” Tim says.

“Due to the technology commercially available for precision planters we could install an auto-adjusting downforce system (DeltaForce), retain the seed sensing at delivery, install Agtron blocked row sensors for the separate granular fertiliser outlets, achieve section control, and furrow property monitoring (Smart Firmer) with liquid delivery of specialty fertilisers, fungicides or insecticides.”

Tim believes this approach provides his family with the maximum flexibility to customise seeding operations per paddock with minimal effort.

“We like having the ability to tune it. Bits just bolt on. It has lots of aftermarket options to fix problems due to its precision seeder heritage, different discs or closing wheels for example, parts that are easy to obtain to fix problems quickly,” he says.

“We wanted something that would bridge the problems of both systems, we loved twin discs but liked the robustness of air seeding.”

The family used a 1910 John Deere air cart with rotary valve with cyclone set up to feed the DB60 precision planter.

“This has allowed us to feed a high positive pressure air cart into a vacuum pressure precision planter CCS tank,” Tim says.

“Therefore, it tops itself up meaning we save time as we don’t have to fill up as often. We tow the air cart for granular anyway so we can utilise its seed carrying ability and liquid system.”

However, he says one downside of precision seeders is they are not suited to the high seeding rates generally used in his region and don’t have the seed holding capacity or the ability to apply granular fertiliser as simply as an air seeder.

Modifications to the new seeder, also mean there are a number of monitors in the tractor cab.

The Rethus' custom built seeder. The family’s custom-built seeding system is flexible.

“At one point I think we had up to 13 monitors in the cab, but as the technology improves we’ve been able to scale back,” Tim says.

“All data is now automatically synced to the cloud, saving us a job and enabling information to be used when needed. You need to be able to access data reliably for it to have any value.”

Challenges

The Rethus’ seeder still has problems with hair-pinning when it rains and the soil and chaff get wet and are difficult to penetrate.

“It’s not so much the stubble because we inter-row, it is the really fine fluffy chaff, especially if it has chemical residue present and is jammed down the seed slot,” Tim says.

“It’s a compromise between sowing shallow for rapid emergence and sowing deep enough to ensure you have cut through the residue, but not too deep.”

The Rethus’ also have trouble with their seeder in sticky soils.

“Wimmera soil is renowned for its stickiness and this can lead to build up on the discs. It does become a mindset change to understand the strengths and weaknesses of your system,” Tim says.

“A disc seeder runs at a higher ground speed whilst sowing, but you may start later and finish earlier if there is surface moisture causing stickiness compared to a tyne.

“In wet conditions the disc can often start earlier, as soon as the surface starts to dry, compared to a tyne that is lifting wet soil to the surface that can build up on press wheels.”

Some of these challenges have meant the uptake of disc seeders has been slow and steady, particularly in the Mallee, but Tim believes they could have a broader fit.

“The key is having a good idea where you want your farming system to go. There is no silver bullet. You’ve got to be prepared to modify and to pick a machine that suits you.”

For this reason, he advocates having a whole-of-farming system approach to business.

“You can’t use a disc seeder, especially a high technology seeder, in isolation. It is like a piece of Lego. It needs to fit into what you are trying to achieve on your farm.”

He also supports having a few options for different on-farm conditions.

“The beauty of a system like ours is that you can easily modify one row unit as a trial. We have tried changing rubber gauge wheels with nylon then back to rubber with metal tipping which acts as a scrapper when we need it,” he says.

“We have serrated discs, thicker discs – stronger with less flex. With these we can get closer with the gauge wheel. When it’s really wet and you’re trying to get the wheel close to the furrow, we have played with the RFM spring coil type which we have found to work well.”

Preparations for sowing

The Rethus family are committed to ensuring an even spread of residue at harvest to avoid accumulation, which can be a problem in a controlled traffic system. They also manage summer weeds which also helps reduce insects and conserve moisture.

Timing and frost management

The family plant by calendar starting on April 1.

“We start with crops that aren’t critical for flowering time: vetch hay, oaten hay, beans, then canola as data is showing canola really needs to be germinated by Anzac day so by mid-April hopefully we are putting that in the ground,” Tim says.

“We then follow with wheat in the southern part of the farm, which benefits from a longer season.

“I believe frost damage isn’t just about one cold day, it’s about how we maximise the health of those plants more than just sowing date, and of course, sowing date doesn’t matter if it doesn’t rain.”

Tim believes heat stress could actually be more of a problem than frost, which is why he prioritises getting seeds in the ground early.

“It’s easy to quantify a frost because it causes a patchy yield map but, with heat stress its even – yield is down uniformly.”

Pests

Mice and snails are also monitored regularly on the family’s farm.

They do a snail survey at the start of March and then again closer to seeding to assess whether baiting is needed. Mice are also monitored, particularly after big seasons.

“We will probably bait these twice this year, once before seeding and then once with the seeder.  It’s part of our strategy to protect the crops when seedlings are small and susceptible,” Tim says.

Committed to reducing the use of insecticides on-farm Tim believes seed dressings could prove a better long-term strategy.

“Russian wheat aphids have not been a problem, because we have been applying seed dressings, which are more environmentally friendly than a broad-spectrum insecticide that can impact both pests and the beneficials,” he says.

Weeds

The Wimmera grower believes good crop establishment is an excellent weed control strategy.

“If you have poor crop establishment that’s where the weeds grow and in our system with minimal disturbance it can take years to get rid of them,” Tim says.

“As growers we can underestimate the competitive ability of the crops. The seeds we plant are plump and vigorous compared with weed seeds. They produce instant competition, so weeds are under pressure early when plant establishment is done well.”

The family believe their zero-till system is helping reduce weed pressure. Pre-emergent herbicides are used post-sowing, which have also worked well.

“Our double disc system doesn’t form a furrow, which prevents bigger rainfall events from washing and concentrating chemicals into the furrow.”

Disease

Tim also believes disease pressure has been eased through the use of seed dressings, which he says can take a crop “deep into the season when the seasonal outlook is clearer making subsequent management decisions easier”.

Nutrition

Using a seeder that can apply two separate fertilisers (a liquid and granular) to the seed furrow, allows the family to fine tune individual crop nutrition requirements.

“We can put on a standard granular phosphorus (P) then top it up with a liquid brew that suits that field and crop, often that involves zinc to get that early vigour, maybe some nitrogen, fungicide or insecticides down there too as its sometimes easier than on the seed,” Tim says.

“If we are worried about the fertiliser toxicity in canola, the flexibility of the liquid system allows us to put on liquid P, which means we can get our unit of P out without causing problems with establishment.”

Top tips

Tim’s top 3 tips for improving crop establishment:

• Have a plan. Do your research. Check out other growers’ machines and share experiences and learnings. Don’t get too complicated early, there is a lot to learn and you are better doing  a few things really well first, before looking for the next improvement.
• Know what your objectives are and also understand the implications of any changes on your existing cropping system.
• Continuously monitor threats (such as pests and disease) to maintain the maximum yield potential targeted as part of your strategy.