The Grimme GL420 Exacta is a potato planter which allows soil cultivation, planting and ridge forming in a single pass. Recently developed with 90cm row spacings, Simon Henley talks to Grimme UK Product Specialist Ed Hodson about the advantages of single pass planting.
When it comes to single pass potato planting, the UK is only just beginning to catch up with Europe. Here in Britain, potato planting is traditionally a plough-based routine, which requires an army of tractors deploying ridgers, bed-tiller and de-stoners, working ahead of the planters to prepare the seed bed.
For large scale growers, this complex operation also requires a melee of support vehicles, including telehandlers, seed trailers, fuel bowsers and (where applicable) liquid fertiliser tanks to keep the planters moving, in addition to the added challenge of dealing with Britains unreliable climate.
Some growers however, are beginning to take another approach. Faced with spiralling input costs and the impending necessity to reduce their carbon footprint, UK farmers faced with these changes are now asking questions about sustainable farming.
An increasing popular solution is to adopt a single pass planting system. One of the companies which has already gained a foothold in this market sector is Grimme.
Combination
The German manufacturer has been marketing its GL420 Exacta combination planter across Europe for the past 11 years. If you have never seen one, perhaps the best way to describe this type of machine is to think of it as a linkage-mounted power-harrow combination seed drill, redeveloped for planting potatoes.
Although not strictly single pass by true definition, this approach to planting potatoes does eliminate the requirement for a ridger and bed tiller, essentially replacing the work of three tractors with one tractor and planter. The machines dimensions should ensure the seed tubers are consistently placed at the required depth in the centre of the ridge, even when working across banks and hills.
In many continental markets the Exacta has typically been adopted by smaller growers with limited resources. More recently however, Grimme UK has noticed an increased demand for this type of system from larger UK growers who are looking for alternatives to eradicate traditional multi-pass planting operations.
Grimme UK potato product specialist, Ed Hodson, says: A single pass system is not necessarily suitable for land with stone and clod issues. The system is ideally suited to land with a healthy soil structure and good drainage.
Previously the Grimme Exacta was only available with 75cm row spacing. However with increasing demand from both the French and UK markets Grimme UK is now offering 90cm row spacing as an option.
Typically we would suggest performing a primary cultivation pass prior to planting. Depending on the soil type and structure the Exacta will work with ploughed ground or land which has been deep cultivated and/or subsoiled.
One of the benefits of using the Exacta is that the tractor does not require row crop wheels. In practice, although deemed a necessity for most planting systems, narrow row crops actually create compaction which affects surface drainage and root establishment.
Modern tyres with flexible wall technology are the most effective way of reducing compaction while using a mounted single pass planting system. The machine can also be specified with section control, variable seed rate and tramlining to increase the efficiency of the planting operation and improve crop yields.
The unit mounts on the tractors rear linkage. Positioned on the support frame are four large subsoiler tines which remove the wheel marks and loosen the soil. Located between the tines is a roller which supports some of the weight of the rotary tiller while the machine is planting and also controls the working depth of the tiller.
Preparation
The rotary tiller is a Grimme GR300 unit equipped with hook or knife tines, as opposed to the speed blade tines used for incorporation applications. To help soil preparation and level the ground ahead of the planter some farmers opt to use a front linkage mounted power harrow. Alternatively, farmers can opt to replace the rotary tiller on the planter with a Lemken power harrow although this currently only applies to 75cm models.
The Exacta planting system is essentially identical to other Grimme planters except instead of dropping the potatoes directly behind the tractor, the system is reversed so the potatoes are planted behind the rotary tiller.
The planting towers and the cups on the Exacta model are the same Grimme-built components used on all Grimme planters, says Mr Hodson.
The advantage of this is not only are we using tried and tested elements but the parts required for maintenance are readily available. Doing this also enables us to incorporate existing technology from other products.
An example of this is the tramline system which operates automatically. The planted rows adjacent to the tramlines are programmed to increase the seed rate. Tramlines will allow more light into the developing canopies on either side and provide more space for root establishment which will support more crop growth.
The Exacta also shares the same control screen as other Grimme planters. This can be used as a stand-alone device or using IsoBus connectivity can be linked to the tractors control terminal. We find a lot of operators like to split tasks between two screens.
