Agricultural engineers have come up with all sorts of innovative solutions to farmers’ problems over the years.
Some hit the big time and are seen on farms the world over, while others flop and end up banished to the back of the shed to gather dust.
Then there’s those in between – technology that lingers in the background, finding a handful of niche uses and limited adoption by hardcore enthusiasts.
Direct injection systems for sprayers fit into the latter category, having been around since the early 1980s, but never truly took off.
However, agronomic and environmental concerns, combined with a drive to cut costs could be about to trigger a slight resurgence in the technology, although some significant barriers need to be overcome first.
The concept is simple and makes perfect sense: you have a ‘carrier’ tank – typically water – and one or more chemical tanks.
Each chemical tank has a pump, which injects neat pesticide at the desired rate into the carrier in a pressurised spray line before reaching the nozzles.
These are all admirable advantages and begs the question, why aren’t there more direct injection systems in use?
So, with both pros and cons to direct injection, what lies in store for the technology?
Demand is growing in North America, driven by weed resistance problems in GM Roundup Ready crops, where growers are looking to spot spraying different herbicides to help control tough-to-kill weeds.
Danish sprayer manufacturer Danfoil also report a small rise in demand for direct injection technology in the past 3 years across Europe, particularly in Germany.
This could be down to some of the flaws attributed to the system being addressed, with companies such as French start-up Diimotion leading the way.
Its PiiX direct injection system has a unique patented dosing unit that claims to have higher accuracy (about 1% variation) than dosing pumps (about 5%) used on more established systems.
It also maintains this accuracy regardless of liquid formulation, aided by pressurising its chemical tanks to 0.5bar, and they have even developed a way to accurately meter and inject powders to within 5% accuracy.
In addition, the firm is working on new valve that will enable real-time variable rate application on wide booms and it is hoped this will allow the use of sensors to recognise weeds and disease and automatically apply the right spray for the job, exactly where it is needed.
So far, its system has only operated in vineyards or horticultural systems, but its CEO Xavier Cassassolles believes the PiiX’s biggest market will be on broadacre-crop farms looking to vary rates to save chemicals.
Similarly, Danfoil is involved in a $2.9m Danish government, universities and industry project which is building up a huge digital image database of weeds at all growth stages in different conditions.
It is hoped sensing drones can then be used to scan fields ahead of a sprayer fitted with direct injection technology, spot spraying or varying dose according to weed spectrum and levels on the move.
Variable rate fertiliser and seed is already the norm on many farms, so it seems translating this into pesticide application is where we’ll see the real growth for direct injection systems – helping cut costs and use pesticides more judiciously.
However, there is a sense that any game changer for the concept rests with the big sprayer and agrochemical manufacturers.
The former need to see demand increase before its worthwhile offering in-house systems for established sprayer models – key to gaining widespread trust in the technology among farmers.
The latter need to come up with a standard packaging solution that incorporates reusable closed-transfer technology to eliminate operator exposure and contaminated waste at farm level.
A fully integrated approach between agchem and applicator makers has already made direct injection the norm for in-furrow applications on potato planters, with products such as Amistar delivered in a returnable 20 litre closed transfer “Link-Pak”.
Once this concept is transferred over to boom sprayers, then perhaps direct injection will be the next technology to hit the big time.
Raven Sidekick Pro – The global market leader in direct injection systems, some sprayer manufacturers offer the Sidekick Pro as a factory- or dealer-fitted option. A 4-pump system for a US-built John Deere machine retails at US$58,000.
Danfoil Multidose 2000 – Danish sprayer manufacturer Danfoil offer sprayers from 1,000 litres to 6,000 litres fitted with its own direct injection kit, developed over 17 years. The system offers up to 6 dosing pumps with an accuracy of less than 5%. A 3,000 litre Concorde trailed sprayer with 5 dosing pumps retails at about $177,000.
Diimotion PiiX – French start-up DiiMotion’s PiiX system can be bolted on to any sprayer for between $21,000-$26,000 depending on specification. The firm will also be marketing a 12-15m mounted sprayer for horticultural use for about $35,000, capable of injecting up to 4 liquids plus one powder.
Teejet Aeros – Like Raven, US spraying technology firm Teejet offer a retrofit system through their dealer network and can be installed on any sprayer.
Direct injection systems
The path ahead