Review: Väderstad Rapid RDA 400S seed drill | Full test & Specs

By: Jaiden Drought

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Jaiden Drought discovers that the Väderstad Rapid RDA 400S seed drill is rapid by name and rapid by nature

The rear of the drill
A big advantage is the staggered tyre arrangement at the rear of the drill
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The Väderstad Rapid 400S (seed only) 4m air seeder with additional Bio Drill carries out seedbed preparation, levelling, drilling, and packing in one pass. It also allows reliable seeding results at high working speed, hence the name.

It’s a multi-purpose drill, allowing the option of cultivating or direct drilling with one machine.

We caught up with Kiwi contractor Gavin Teal and his son Daniel, who are familiar with the gear produced by Swedish giant Väderstad and recently added the Rapid 400s with Bio Drill to their fleet.

When we visited, like much of New Zealand, the ground where they mainly contract in the south of the North Island was showing the effects of a wet winter, followed by a recent dry spell, meaning there was moisture below but the top was pretty crusty.

Gavin runs a large range of Väderstad gear. He has a Carrier with Bio Drill as well as another 3M Rapid (box type), which is a 2011 model. The only work his original Rapid required was replacing a single bearing.

In terms of maintenance, he has just replaced the seeding discs after more than 3000ha. It’s this reliability and flexibility which the drill allows their business that made the decision to upgrade to the Väderstad Rapid 4m a no-brainer.

The main benefit over the original box drill is in low seeding rate applications such as turnips. This machine still has the 5-inch or 125mm row spacing, so has all the same great features of the box drill, except this one is run on air with electronic calibration and the impressive controller (which I will expand on later).


The Väderstad Rapid 400S 4m air seeder behind a tractor
At the headlands, the wings lift higher than the main section to reduce the risk of scuffing


The ability to use the Väderstad Rapid in either worked or direct drilling ground is a real bonus. Given that farmers and contractors are never sold on a one-trick pony, the Väderstad Rapid ticks a lot of boxes. It can prepare and drill ground in a variety of challenging conditions, as you get high coulter pressure and a decent amount of coulter travel.

The long length of the machine is the only real potential issue. However, the pivoting two-point linkage headstock does give manoeuvrability in and out of gateways, as well as over undulations in the paddock, particularly short sharp knobs, which can be tricky for any drill.

The two-point headstock allows you to lift the linkage arms up and over knobs as opposed to the front discs just bulldozing through. This is particularly helpful in sandy country as it keeps that precious topsoil intact.


Four-stage seeding

The way the Väderstad Rapid can work in either cultivated or non-cultivated ground is due to its unique four-stage system. In one pass, this does the whole process (seedbed preparation, levelling, drilling, and packing) saving time, fuel, and moisture.

XHED: First stage: preparation

The front incorporation discs allow cultivated or lightly pugged areas to be given just a little tickle up and create that nice amount of tilth. The aggression can be altered from the cab depending on the conditions.  

This machine had what is called the system discs in the front: two rows of offset discs followed by narrow levelling paddles to gently smooth the surface before the next stage.

Second stage: seeding

The Väderstad Rapid depth control system (which is adjustable from the cab) uses each packer wheel to control the drilling depth of two seed coulters with a unique mechanical linkage.

The coulters are rubber mounted, which allows more stable drilling at high speed while also allowing coulter pressure between 117kg and 255kg depending on the setting.

The main air seeder is run by a hydraulically driven fan with hydraulic metering, while the Bio Drill runs off the same air supply. However, this has electric metering with radar.

At the base of the seed hopper, seed enters the hydraulic metering system (with seed rates from 1.5kg/ha up to 500kg/ha). The hydraulic drive allows high seed rates also at high speed.

The high-mounted fan is neatly incorporated and out of the way of dust and debris. This sucks the seed from the metering system to the distribution head, which is tucked into the hopper and out to the seeding boots.

The stairway and platform up to the seed hopper have wide non-slip steps and an area where you can throw bags up to from the ground. For the more industrial jobs, as this is a folding machine, the 2900-litre hopper is large enough to hang bags of seed over it with a normal front-end loader without the need for a telehandler.

Third stage: packing

The big advantage with the Väderstad Rapid is the staggered tyre arrangement at the rear of the drill. This does two things.

Firstly, it’s the transport wheels for the machine that allows weight to be carried across all the tyres, reducing road wear. Secondly, as the roller is incorporated, there’s no need to tow an additional rear roller, making manoeuvrability much easier.

The reason it’s staggered is also twofold. Firstly, the wheel is attached to two seeding coulters. This is done with linkage, which allows consistent seating depth of those two coulters.

If contour changes across the width of the drill, the wheels attached to the two coulters can all move independently, allowing great contour, following with the added advantage of rolling across the width of the drill at the same time.

The second reason they are staggered is so you don’t have all the rollers in a row. In wet soil conditions this eliminates waving across the paddock, or in super-dry powdery conditions, a bow wave will not be carried in front of the roller, giving a much nicer seeding finish and again more-consistent seed depth.

Fourth stage: finishing

The following harrow is adjustable and leaves a nice clean finish after the seeding from both hoppers. This allows the Bio Drill outlets to be mounted along the harrow for the likes of slug bait distribution.


Bio Drill

The Bio Drill is the rear air seeder, which allows great flexibility. You can run fertiliser through the main hopper and seed through the Bio Drill, or run grass seed and slug bait or seed through the main hopper and clover separately through the Bio Drill. It’s like a second box, only smaller.

With a large, easy-to-fill hopper with its own steps and platform, the Bio Drill is integrated into the same control system. Calibration is simple and performed in a minute using the remote-control box fitted on the Bio Drill.

The only issue with the Bio Drill is that it’s slightly hidden and does hang out a little bit. The tail swing may collect the odd gatepost.


The E-Control hat

The E-Control hat where all the data is stored and sent between the drill and the iPad controller


Personally, I think this is one of the best features of this machine. The ability it gives you, plus the clear, colourful display make it super user-friendly. It’s not all for show either. It really does have some great features:

  • The iPad-based E-Control wirelessly connects to the machine, enabling full access to its functions and data
  • The high-resolution iPad display clearly displays data
  • E-Control is a fully portable. When calibrating the machine, for example, you can take the portable iPad out of the tractor and control the calibration from outside
  • The iPad is wirelessly connected to the machine via a gateway (the little yellow dome on the machine). The gateway creates its own wireless network so there is no need for internet access
  • All machine data is stored in the gateway on the machine and not in the iPad, meaning the data is always secure. If the iPad stops functioning, you can get a new one and simply download the app. The iPad can also be used for multiple machines on the farm, such as the Rapid and Tempo.


The bottom line

It’s hard not to be impressed by the Väderstad Rapid, which is available through Landpower in Australia.

It’s obvious why this is the drill of choice by many contractors – for its flexibility, reliability, and ability to seed accurately at high speed.

The E-Control takes the user-friendliness to the next level. It is colourful, intuitive, and easy to use. It allows you to take it outside the cab and if it dies or gets damaged, all the data is stored in the machine and not the iPad, so no data is lost.

High accuracy, high speed, high build quality, and user-friendliness make the Väderstad Rapid something to put on your wish list.



Excellent build quality

E Link is user-friendly

The combination of the Bio Drill adds versatility

Has the ability to work in cultivated ground or direct drill

Unique offset packer and transport wheels all in one

Great for incorporating crop residue and drilling in one pass

Large hopper with accurate seed distribution of rates up to 500kg/ha

High-speed, high-accuracy drilling

Up to 255kg coulter of ground pressure


The machine is 8m long and, as the wheels are right at the rear of the machine, it can be a little tricky to navigate tight spots

The Bio Drill is completely unseen from in the cab and will have some tail swing that could collect the odd obstacle

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