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Agrowdrill 425 coil tyne undercarriage on a AD240 seed drill

Agrowdrill Undercarriages

Our range of coil, spring, and disc undercarriages seamlessly blend precision and versatility, offering you the best of both worlds in seed drilling technology. Whether you prioritize pinpoint accuracy in seed placement or the adaptability to handle diverse soil conditions, our undercarriages are engineered to meet your needs. Discover the perfect balance for your farming operation, enhancing both efficiency and yield potential with your Agrowdrill.
View Agrowdrills Which Undercarriage do I need?

Coil Tyne & Disc Assemblies

425 Coil Tyne

The Agrowdrill 425 coil tyne has been a mainstay of our seed drills for years – and with good reason!

The robust design ensures the tyne has the strength to last season after season for sowing in wet, dry, or high-trash conditions.. The inverted-T shape of the Baker Boot point opens a groove in the soil designed to minimise soil disturbance and ensure effective seed placement.

The 425 coil tyne has a maximum breakout of 136kg (300lbs), an underframe clearance of 620mm, and is available as an undercarriage option on the AD083, AD140, and AD240 seed drills.

401 Double Disc

The 401 Double Disc is ideal for zero-tillage sowing applications. It comes with a matched pair of plain and notched discs that open a narrow funnel for the seed whilst ensuring maximum trash flow. The spacing between the discs can be modified with optional spacers to better suit a range of soil conditions. The self-cleaning design breaks through stubble and trash to create a clean soil furrow with minimal soil disturbance.

The 401 Double Disc Unit has a downforce of 205kg (2010N), an underframe clearance of 620mm, and is an available undercarriage option for the AD083, AD140, and AD730 seed drills.

Spring Tyne Assemblies

251 Spring Tyne

The 251 Spring Tyne offers users a robust solution to meet the needs of large-scale direct drilling.

The Baker Boot point creates a soil micro-climate ideal for seed germination and maximising crop potential. It has the strength to handle seeding in a variety of conditions whilst maintaining the accuracy and reliability that Agrowdrills are renowned for.

The 251 Spring Tyne has a maximum breakout of 114kg (251lbs), an underframe clearance of 620mm, and has been designed for the AD730.

552 HD Spring Tyne

This is a heavy-duty tyne for the AD730 Agrowdrill, with a breakout of more than double the 251 tyne, and a higher underframe clearance of 750mm.

Featuring toughened tungsten-hardfaced wedge points, the 552 HD Spring Tyne's sturdy construction makes it capable of drilling deeper for longer through the toughest terrain, including sandy, hard, and dry soil conditions.

The 552 HD Spring Tyne has a large breakout of 250kg (550lbs) and is exclusive to the AD730.

Disc vs Tyne Seed Drills: Which undercarriage is right for me?

When it comes to choosing between a tyne or disc opener undercarriage configuration for your seed drill, each option comes with its own set of advantages and considerations.

The Tyne Undercarriage

Tyne undercarriages have a longstanding reputation amongst farmers for their versatility and durability, making them a reliable choice for various farming environments. 

AD240 Agrowdrill with tyne assembly on white background

Simple, Yet Versatile

Because of their straightforward design, tynes offer farmers a cost-effective alternative with fewer moving parts compared to disc units. This makes them an attractive option for those seeking a lower initial investment in the machine and reduced maintenance expenses, all while maintaining seeding performance.

Tynes generally come in either a spring or coil rebound design, and can effectively handle a wide range of soil types and conditions, being equally adept at seeding pre-cultivated paddocks as well as direct-drilling into existing pasture, crops, or stubble (no-til). 

Inverted t slot created by baker boot on a tyne seed drill

Baker Boot: 'T' Groove

The popular “baker boot” point produces an inverted 'T-slot' in the soil into which the seed is placed, allowing the sides of the slot to fall back as the tyne passes. The T-slot provides an ideal micro-climate for seed germination by allowing the ‘chamber’ to admit light and moisture but conserve heat, conditions that are ideal for consistent seed placement, uniform germination, and rapid root growth.

The tyne and boot combination clears away vegetation and trims existing roots, whilst the attached seed tube sets the seed firmly at the base of the T-slot. This positioning ensures the seed maintains contact with moisture drawn up through the soil. 

Shop Agrowdrill Baker Boot Points
Agrowplow 425 coil tyne with 620mm underframe clearance

Coil Tyne with Baker Boot

Made from strong 25mm spring steel, coil tynes are designed for strength and durability, minimizing lateral movement to ensure a straight trajectory through the soil. Typically arranged in a wide, staggered pattern with either a left or right-hand coil, they facilitate the flow of debris and are equipped with replaceable points for wear and tear.

The Baker Boot and Tyne combination provides accurate seed placement and seed-to-soil contact with minimal soil disturbance, for excellent seed germination and plant establishment in most soil types and climates.

Tynes with Coulters

Tynes with Coulters

Leading coulters fitted before the main undercarriage are popular with farmers looking at improving the performance of their disc or tyne seed drill in high-trash conditions. The coulter discs clear a path ahead of the main soil opener, cutting through soil residues and trash.

Coulters help prevent trash buildup, which decreases seed accuracy and potentially leads to uneven seed germination. Coulters are generally set to cut slightly shallower than the seeding depth and help decrease soil scatter and disturbance.

Coulters can be fitted to a machine already with a double disc assembly (called a ‘triple-disc’) or in front of a tyned seed drill. The latter setup is popular with many Australian farmers as is combines many of the advantages of disc seeding with the advantages of operating a tyne seed drill.

Is a Tyne Seed Drill Right For Me?

If adaptability, low cost of entry and performance in wet conditions are high on your priority list, the Tyne undercarriage could be the right fit for your seeding operation. Adding coulters can enhance the drills' versatility and performance in high-trash conditions.

Cost Effective:

Seed drills with a tyned undercarriage are generally much cheaper to purchase than disc seeders.

Ease of Maintenance:

Tyned drills are simpler to maintain in the field as there are no moving parts. Regular maintenance tasks, such as changing worn-out points, are straightforward and cost-effective.

Flexibility and Versatility:

Tynes offer greater flexibility and a wider drilling window, allowing farmers to plant crops even in unfavourable conditions. Tyne drills exhibit greater versatility across different soil types, ensuring effective seed placement in varying agricultural landscapes.

Herbicide Compatibility:

Tyne systems permit the use of pre-emergent herbicides like trifluralin, aiding in weed management.

Wet Conditions:

Tynes excel at placing seeds accurately in wet conditions. The soil channels prevent clumping and compaction, whilst their minimal disturbance nature preserves the soil's water absorption capabilities and enhances drainage, allowing excess moisture to escape the seed zone. These conditions are vital for preventing water pooling around seeds, ensuring optimal germination and plant growth.

Reduced Residue:

Tyne drills leave behind a reduced mulch layer, minimizing pest damage and the need for fungicides.

Fertiliser Banding:

Tynes tend to band fertiliser better than disc units, offering an efficient nutrient placement for optimal crop growth. 

Less Soil Compaction:

Seed drills with tyne openers exert less pressure on the soil surface, as pulling the tynes forward creates a downward force holding the tines in the soil. Significantly less weight is required to gain and maintain penetration with a tyne opener compared to a disc, minimising soil compaction.

Water Drainage:

Narrow channels created by tine drills facilitate water drainage, reducing the risk of waterlogging and improving soil structure.

Seed Placement Accuracy:

Tyne drills offer superior and precise seed placement, crucial for uniform crop emergence, especially in wet conditions. The narrow tines create well-defined seed furrows, ensuring that each seed is placed at the desired depth with minimal variation.

Depth Variation:

Most tine drills are on a fixed frame resulting in varying depths of seed across the width of the drill when going across uneven ground. 

Soil Disturbance:

Tyne drills inevitably disturb more soil than disc drills, which may hinder weed germination but could enhance crop establishment in some scenarios.

Residue Management:

Tyne openers are less effective at managing surface residues, potentially impacting moisture retention and weed control. 

Reduced Trashflow Performance:

Tyne drills can be challenging when sowing in dense residues, which build up around the tynes and dragged with the machine, often resulting in dumps in large piles. This can result in inconsistent seeding. Tyned machines struggle in heavy stubble with narrow spacings.

Wider Row Spacings:

To combat trash build-up, tyned machines often have wider row spacings. However, this is generally a disadvantage for farmers looking to improve moisture reserves in untilled soils.

Soil Throw:

Tyne systems create more soil throw, posing challenges for no-till objectives and soil conservation efforts.

Rock Throw:

In rocky conditions, where rocks are buried beneath the soil, tynes may pull these up and 'throw' them, posing potential risks of damage to machinery or injury to people.

The Disc Undercarriage

Disc undercarriages have gained popularity in recent years for their precision planting capabilities.

AD083 with Double Disc undercarriage

Consistent Seed Depth

Discs excel in providing consistent seed depth control which is crucial for optimizing crop yields, and offer significant benefits such as reduced drawbar requirements, higher operating speeds, and improved efficiency.

Disc drills are known for minimal soil disturbance during the planting process, increasing moisture retention and preserving the soil structure and associated microorganisms that contribute to soil health.

AD083 with 401 double disc undercarriage has 620mm clearance

Single, Double and Triple Discs

Double disc openers offer superior trash handling capabilities to single disc units, which tend to collect grass and residue quickly, reducing their ground opening ability and seed placement accuracy. This is particularly important when planting in soil that has not been tilled for many years

Triple-disc openers add a leading coulter before the double-disc unit and further enhance the ability of the seeder to cut through trash and stubble in minimal tillage operations. 

Ground-Following Discs

Ground-following disc designs are praised for their ability to maintain consistent down pressure independent of the drill's weight. The parallelogram mechanism offers superior uniform seed placement across uneven terrain. These drills incorporate a press wheel that follows immediately after disc and seed tube which presses the seed into the soil, closes the furrow, and lightly compacts the soil to create an even seed bed. Such precise placement contributes to enhanced crop yields by ensuring seeds are delivered evenly, regardless of the field's contours.

V slot and seed placement created by double disc opener on a seed drill

Disc Openers: 'V' Slot

Double disc undercarriages utilise a pair of angled rotating discs. The rotating disc creates a narrow “V” slot into which the seed is dropped. The slim profile of the discs allows for closer row spacings to maximise cropping efficiency. They also leave a smoother soil profile than tynes and will assist in reducing water runoff which makes them more suited to sowing in dry soils.

Is a Disc Seed Drill Best For Me?

If you're seeking precision in high-trash, dry, or rocky conditions, alongside improved seeding efficiency, an Agrowdrill with a disc undercarriage may be your ideal choice.

Accurate Seed Depth:

Disc drills offer independent movement on each assembly, allowing for precise and consistent seed depth control.

Soil Disturbance:

Disc drills excel in creating superb seedbeds with minimal soil disturbance, ideal for drilling into tall, dense cover crops.

Weed Control:

The narrower row spacings allowed with disc drills help crops fight off weeds, reducing herbicide reliance.

Dry Conditions:

Disc drills improve rainfall infiltration and moisture retention in dry soils. Soils drilled with discs also tend to be more resistant to wind and water erosion. In very low rainfall conditions, drilling through stubble cover can significantly increase grain yield.

Rocky Conditions:

Discs may improve sowing performance in rocky conditions. Discs tend to roll or ‘bounce’ over stones and rocks instead of pulling them to the surface like tynes tend to.

Efficient Sowing:

Disc systems enable faster sowing rates, as there is no need to fracture the soil. This enhances operational efficiency and productivity, particularly when needing to sow large areas. The narrower row spacings enable a denser seeding profile.

Reduced Input Costs:

Disc systems cause less drag and reduce fuel use, offering potential input cost savings for growers such as fuel and time. 

No-till Farming:

Whilst zero-till seeding is very achievable with a tyne seed drill. disc seeders can better plant through stubble retained for many years with minimal soil disturbance, contributing to soil stability and retention of organic matter.

Mixed Pastures:

Disc seeders can plant supplementary pasture seed species within existing pastures without causing harm to existing crops.

Open Slot Effect:

Disc drills may leave seeds vulnerable in open slots, especially in wet conditions, increasing the risk of chemical damage and pest infestation. Presswheels or soil rollers that close the furrow over the seed and press it into the soil can mitigate this issue.


Discs may not cut the stubble but only push the stubble into the furrow, inhibiting seed-to-soil contact and increasing the risks of the seed springing back with the straw.

Maintenance Costs:

Disc drills entail higher upkeep costs due to their complex design and moving parts. They require constant upkeep to maintain consistency and accuracy.

Susceptibility to Stones:

Disc drills may struggle on rocky land with high stone content, as they bounce over the stones which leads to increased wear on the discs and undercarriage assembly and reduced effectiveness.

Wet Conditions:

Disc seeders exhibit limited adaptability in wet conditions, primarily due to the risk of open slots and excessive moisture retention causing crop damage during heavy rainfall before seedlings are established fully. The absence of tynes for levelling wheel tracks, combined with the rotation of discs, can exacerbate soil compaction along the seeded rows in wet conditions. This compacted surface impedes water infiltration and root development, adversely affecting crop growth.

Weight Requirements:

Disc drills require significant weight to ensure there is enough downforce to achieve effective soil penetration, which can contribute to soil compaction.

Herbicide Limitations:

Disc systems cannot use certain pre-emergent herbicides that penetrate stubble layers, potentially affecting weed control efficacy.

Pest Management:

Disc drills used in a no-til system may create a favourable environment for certain pests, such as slaters and millipedes, in the heavy mulch layer, increasing the risk of crop damage.

Disease Management:

Retained residues in disc farming systems may contribute to disease proliferation, necessitating careful variety selection and an effective fungicide program.

Still not sure?

Contact our sales team on 0429 393 350 to discuss the right undercarriage option for you, or speak to your local Agrowplow dealer.
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