If planting season was a rock concert, seed opener blades would be the stars of the show.  But just as a rock star is nothing without the band, so seed opener blades rely on a supporting act – gauge wheels – to do their job.

The seed opener and the gauge wheel work in tandem to open a furrow at the correct depth, leaving enough soil in the right place for the closing wheel to place back over the seed.  The specification of your gauge wheels will depend largely on which planter you’re running – but factors such as soil moisture, tillage system and even crop type can all inform your decision about which gauge wheel to choose.

Here’s a look at some of the options available on gauge wheels, and the factors to consider when making a choice.

Gauge wheel placement

The vast majority of planters have the gauge wheel positioned right next to the seed opener blade – and for good reason.  This is the closest practical point to where the seed drops, and therefore the point at which you can achieve the most precise depth control, which has a direct impact on soil contact and seed germination. 

Locating the gauge wheel alongside the blade also prevents soil from being thrown out of the furrow by the opener blades. This is important in no-till systems where minimal soil disturbance is the name of the game, and is also vital for successfully closing the furrow, since the close wheel can’t replace soil that is thrown too far from the furrow.  It’s also important if your soil is prone to waterlogging, since moving too much soil out of the furrow can lead to depressions in the surface that collect water and can cause seeds to rot.

Soil compaction

The function of the gauge wheel is to hold down the sidewall of the furrow that naturally wants to rise up as the seed blade passes through.  This results in a clean furrow that facilitates precise seed placement, and enough soil to effectively close it again.  But an unwanted side effect of this is compaction of the sidewall, which can in itself cause problems with seed-to-soil contact, resulting in restricted root growth, poor emergence, and lost yield potential.

Some manufacturers – such as Case – have attempted to get around the problem with design tweaks to their machinery.  The Case IH gauge wheel uses a Reduced Inner Diameter (RID) tire with a unique relief profile that leaves space for the soil to bulge upwards along the edge of the furrow, while still retaining a clean furrow profile.  The system works thanks to a ‘seed boot’ that runs along inside the furrow itself, preventing the loose soil from collapsing inwards before the seed is placed.

Choosing a width

Gauge wheels are available in a range of widths, typically 2.5”, 3” and 4.5”, with the latter being the most common.  The width you choose depends on the importance of depth versus compaction – the narrower the wheel, the more depth you’ll achieve since the wheel is less prone to obstruction by trash or clumps of soil.  

2.5-inch wheels are typically run on twin row planters because there isn’t room for a wider wheel.  3-inch wheels tend to be used in strip or ridge till systems, where they help to achieve a good balance between depth and soil compaction – but there’s an increasing movement towards their use in no-till systems too because of their ability to run smoothly through trash.

Gauge wheels over 4 inches in diameter are most commonly used in conventional tillage systems, but in no-till they’re an ideal choice on heavy soils where plugging is an issue.  They serve to keep the row unit out of the ground and maintain consistent depth.

Spoked or solid?

Gauge wheels come in both solid and spoked profiles and the choice really comes down to soil conditions, farming system – and personal preference.  The idea of spoked gauge wheels is that mud and residue can escape between the spokes so they don’t get clogged up, and also so that it’s easier to clean out any debris that gets lodged between the seed disc and the gauge wheel.  However, in no till systems – particularly corn fields – the leftover corn stalks and other trash can end up getting tangled in the spokes, leading some farmers, especially those in drier climates, to opt for a solid wheel profile.  

Which tires?

Gauge wheel tires always have a convex profile to reduce drag and therefore increase agronomic efficiency. They have traditionally been made of rubber, which has a key benefit – its flexibility allows the tire to easily shed mud and debris as it moves along.

But rubber tires struggle to stand up to the extreme wear they encounter in conservation tillage system – especially no-till, where corn stalks can shred up a tire like nobody’s business.  For this reason, polyurethane tires are becoming more popular for gauge wheels.  Polyurethane wheels retain their lips for much longer which results in a superior furrow – but they can also be heavy and hard, leading to increased soil compaction, and the risk of the tire bouncing over an uneven surface, leading to inconsistent depth.  In addition, polyurethane wheels don’t shed mud easily so they are prone to plugging.

The solution?  Rubber semi-hollow tires like the FarmFlex range by Otico, available from Wearparts.   These tires are manufactured from rubber and are hollow like a normal tire, but the proportions have been altered to deliver superior performance.  The void in the centre is just big enough to give the tire that necessary flex, while the rubber is thick enough to be puncture-proof and deliver that long-wearing, semi-rigid lip.  Superior shock absorption ensure consistent planting and crucially, less wear and tear on your planter.  Tire profiles vary by machine, and FarmFlex has options to fit them all – including the RID option for the Case IH planter.

For more advice on which gauge wheels are best for a specific planter or how you can tackle particular in-field challenges, contact our knowledgeable sales team.

If necessity is the mother of invention, it follows that when it comes to knowing what tools farmers need to get the job done, nobody knows better than farmers themselves.

Almost every piece of farm machinery we use today can trace its roots back to an implement that was designed by a guy looking to solve a problem on his own land – because when you see the problem close up, you’re best placed to develop a solution.

That’s why our customers – ag dealers and the farmers they serve – are integral to the NPD process here at Wearparts.  Where OEM manufacturers are focused on the big, ‘one size fits all’ solutions, as an independent business we’ve got the agility and the grassroots knowledge to respond to the specific challenges farmers are facing in a much more intuitive way.

Inspired by experience

Take our seed opener assemblies, for example.  The points of difference between OEM openers from different manufacturers are negligible – but after attending a workshop with a group of farmers, we learned that most conventional assemblies were coming up short on some key factors: hardness, bearing size, sharpness and bevel length.

So we took this information to our NPD department, and the result is our unique seed opener assembly, developed in conjunction with French company, Forges de Niaux.  

Our seed openers look the same as most – but look closer and you’ll find we’ve used an innovative heat treatment process that delivers a harder edge while retaining flexibility through the center; a longer bevel that stays sharp for longer; and a larger bearing and rivet.  What this adds up to is precise performance, a longer wearlife in the field, and less costly downtime for the farmer.  The differences are subtle, but in a game of fine margins, they can add up to significant uplift in a farmer’s bottom line.

Innovating for excellence

This NPD process isn’t unique to our seed opener blades.  We’re always listening to farmers and thinking about ways we can improve or update our products to better meet the challenges they face, in an industry that gets more competitive every year.

At any given moment, we’ll have a number of products at various stages in our NPD process, which starts with our sales team gathering feedback from customers and culminates in the launch of a new tillage or planting tool.

For obvious reasons, we can’t develop a new product every time we get a query or some feedback from a customer – but over time, we’re able to build up a clear picture of where there is a need, based on the volume of requests for a specific product adaptation or new solution.  

Our sales team are out on the ground right across the USA, listening carefully to what dealers and farmers are saying about our products and about our competitors, so once we’ve established there’s a need for something new or different, we move to the next stage of the process.

Advanced agronomics

We start by scoping out the design and product engineering parameters, as well as the commercial side.  Do we need to develop something new from scratch, or can we adapt an existing product?  What will it cost to make?  What do we need to sell it for – and how do the costs stack up for the farmer in terms of cost per acre?  Only when we’re sure that it makes agronomic sense will we proceed to actually develop the concept.

This process begins in our engineering department where, following a product request from the sales team, our designers begin by creating a CAD drawing and/or a 3D model of the product.  Once they’re happy with this, they submit it to the preferred manufacturing vendor – we use vendors across Europe, North and South America and some in the Far East – for one or more prototypes to be made.

Once we receive the prototype/s at our headquarters in Gothenburg, Nebraska, we proceed to carry out fitment and field tests.  The fitment tests are to ensure that the prototype/s are fit for purpose – that it fits the intended machine, and that it moves freely, interacting with any other components as it should.  Once we’re confident that the product works ‘on paper’, it’s time for the real test – in the field!

Field tested, farmer trusted

We carry out field tests to establish the precision, effectiveness and wearlife of all our ground-engaging components, comparing them against data from our own similar products where available as well as comparing directly with competitor products where appropriate.  

This process quickly shows up where any adjustments need to be made on the design and manufacturing side.  Prototypes may travel back and forth to the manufacturer a number of times until we’re completely satisfied with the performance and specification.  As a result, the time frame for our NPD process varies significantly from product to product – it can take up to a year or more to bring a product from concept to market-ready component.

Once we’re satisfied that the new product meets our stringent requirements on performance, wearlife and value for money, we place our first batch order, and recurring purchase orders thereafter.  All product is received into our Nebraska HQ and quality checked before it’s stored in our warehouse ready for shipping to our nationwide dealer network.

We want your feedback

Whether you’re a farmer or an ag dealer, if you’ve got an idea for a new product or a modification to our existing range that would save you time and money, we want to hear from you!  Get in touch to add your feedback to our database, and shape the future of tillage and planting with Wearparts.

Growing food crops is the most nutrient-intensive of all farming practices, requiring optimal soil conditions in order to achieve the high yields farmers need to make their businesses profitable.

Before the invention of man-made fertilizers, farmers used natural methods – such as crop rotation, rotational grazing and manure spreading – to return nutrients to the soil. But as the intensity of crop farming has increased, farmers have become more and more reliant on man-made fertilizers in order to stay competitive.

Conservation tillage represents an effort to limit that reliance by incorporating some of those traditional, natural soil conditioning methods into a modern-day commercial farming model. By leaving crop residues in place and not disturbing the soil too much, natural microbial activity can restore some goodness. But it’s not enough on its own, and so farmers have had to seek out methods of soil conditioning that align with their desire to preserve the soil structure as much as possible – hence the invention of fertilizer knives!

What is a fertilizer knife?

A fertilizer knife is a non-rotary tool that is used to inject in a dry, liquid or anhydrous (vapor) fertilizer into the field. There are many different types of fertilizer knives available, offering the farmer many options in terms of depth, soil disturbance and cost per acre. These include front and back-swept styles, central and side application models, and profile/tip variations. Choosing the correct knife for your farm depends on soil type, the toolbar being used, the planned crop and its nutrient needs, the type of fertilizer being applied and the level of moisture in the soil.

Why use fertilizer knives?

Fertilizer knives are the preferred method for fertilizer application for many different reasons. By putting the fertilizer directly into the ground, you avoid issues with runoff on sloped sites, dilution due to rainfall, or evaporation of liquid product into the air. Fertilizer applied to the soil surface takes time to penetrate to the depth where it can be effectively used by germinating seeds and later, crop roots – but applying the fertilizer at depth ensures these nutrients are immediately available to the young plants.

Using fertilizer knives also creates optimal conditions for seed germination by breaking and lifting the compaction layer without turning over the soil surface.

How are fertilizer knives used?

Fertilizer knives can be fitted to a toolbar or cultivator in either a bolt-on or auto-locking format. The farmer can have a cultivator with the same number of shanks at the same spacing as his planter or an odd number of rows depending on the application. Even rows mean that the fertilized furrows will eventually align with the seeding furrows during planting season for optimal results. The tip of the fertilizer knife penetrates the soil and the foot then fractures and lifts the compacted layer to create an aerated furrow. A tube to the rear of the knife shank delivers fertilizer into the furrow, and then a wedge-shaped closing mechanism that catches the edge of the furrow and closes the soil over.

Which knife is used for which fertilizer type?

Besides what fits your specific machine and soil type, you’ll need to select the right knife for the type of fertilizer you want to apply. Anhydrous ammonia (NH3) for example, needs to be applied deeper than other fertilizers because of its hazardous nature – you don’t want it escaping into the air, so you need a knife that penetrates to a depth of 8 or more inches. A narrower tube also ensures more accurate and safe application.

For liquid fertilizer, application is at a similar depth, but a wider tube will be required. For dry fertilizer, an even wider tube is needed but a shallower depth is optimal – a backswept knife may be preferable if soil conditions allow. Knives may also be equipped with two different tubes for simultaneous application of more than one fertilizer type, or for the addition of fungicidal and insecticidal treatments.

Wearparts Fertilizer Knives

We carry fertilizer knives to fit all types of applications, with alternatives to almost every branded blade on the market including Wako, Wiese and more.

We offer tube sizes of 3/8” OD & ½” OD, thick walled tubes for increased life; chrome tubes available on most knife models. Dual tube knives also available. Foot profiles of the narrow 3/8” wide to a mole style knife with a 1-7/8” wide foot piece are available. Optional chrome inserts are available on almost every knife for longer life and durability. Sealers are also available. Our NPD department is currently in the process of developing knives for anhydrous and backswept specifications – stay tuned for details on these and more product innovations coming soon at Wearparts!

As with all our products, you can expect high quality manufacturing and a durable, fit-for-purpose product at a competitive price. We currently have excellent stock levels, with immediate shipping available on many of our fertilizer knives. To find out more or to inquire about becoming a dealer, get in touch!

**we have all coulter options available for fertilizer knife systems as well**

Fertilizer applicator outfitted with Wearparts fertilizer knives and coulter blades