Whether you prefer dribble bars or nozzles for putting on liquid fertiliser, you probably have sound reasons for making that choice. But recent advances in both types of nozzle technology mean that the pros and cons have shifted somewhat.
The Agroco Umbrella nozzle developed by grower Oliver Cooper 20 years ago started something of a revolution in liquid fertiliser application.
His idea was to place horizontal outlets around the rearward side of the nozzle to produce seven liquid streams of equal flow but in an asymmetrical pattern that overlaps the output from the adjoining nozzle to achieve even coverage.
It’s been an enduring concept and one largely unaffected by changes in boom height. It has been copied in several respects by other manufacturers (which is a compliment in itself) and the Umbrella nozzle itself remains in production.
However, these days it faces competition from alternatives including the Hardi Quintastream, which produces a symmetrical pattern of five streams but with a higher volume from the central one than from the outer overlapping streams.
There’s also the TeeJet StreamJet SJ-7, which produces seven symmetrical liquid streams of equal volume.
Horizontal outlets arranged around one side of the nozzle give an “umbrella” pattern from the StreamJet SJ-7.
Albuz, meanwhile, provides a hard-wearing ceramic metering orifice for its ESI six-stream tip while Lechler favours stainless steel for the wear-prone metering discs in its FL tip, which has five horizontal outlets for a symmetrical “umbrella” style output.
The three-outlet Albuz EXA design, which also features a ceramic metering insert, produces three solid streams from one vertical and two slightly angled outlets to give a more positive delivery into a crop canopy. Hypro-EU takes this concept a step further with the newest nozzle in this sector, the “ESI”, which produces six angled solid streams from a compact design.
Although recommended for use at the usual 0.5m above the target and at up to 4bar pressure, recent trials and field experience suggests it has the versatility to work at higher boom settings for improved penetration and at higher pressures for increased application rate flexibility without adversely affecting its efficacy.
Fertiliser dribble bars have moved on from the days when making a significant change in application rate meant removing each one, swapping the metering disc and putting it back on to the boom.
Built-in rate selector mechanisms – and pushbutton rate selection from the tractor cab on the latest design – make dribble bars more convenient to use for operators who prefer them over nozzles.
Their key attraction is that the application pattern is unaffected by boom height. On the downside, they are bulkier, can be prone to twisting out of alignment and are more susceptible than nozzles to being damaged or ripped after being caught on foliage, especially during road travel down narrow, hedge-lined lanes.
One solution to the alignment issue is to mount the dribble bars permanently on a second spray line so they can be held securely in place by plastic ratchet ties. Bateman’s Accu-Rate bars can be kept in alignment with joining links or by elastic ties attached to the hook end of the new AutoStreamer from Billericay Farm Services.
For quicker and easier rate adjustment, the Accu-Rate dribble bar from Bateman Engineering has a stainless steel rotary flow restrictor. Each of the four positions is selected from beneath the device using a key.
In addition to the four-outlet 0.5m standard bar, Bateman also produces a shorter version for use at boom hinge points; the body has three outlets plus a flexible remote outlet that can be mounted on a bracket in a suitable position on the boom.
The 0.5m Streamer from Billericay Farm Services also has a rotary selector but with five different settings selected using a finger wheel between the inlet from the sprayline and the dribble bar itself.
With the Streambar MultiRate introduced by Chafer Machinery last year, operators select one of six different application rate settings using a slide carrying different-sized flow restrictors.
As with the Accu-Rate design, the Streambar’s ports are fed individually to prevent the upper outlets being starved of liquid when applying fertiliser across a slope at a low rate.
|Slimline AutoStreamer dribble bar from Billericay Farm Services has a variable rate flow valve that responds to system pressure, so rates can be changed using the sprayer controller.|
With the new AutoStreamer applicator, Billericay Farm Services has automated rate changes by replacing fixed size flow restrictors with a pressure-sensitive variable flow valve using a simple rubber sleeve inside the inlet.
The valve will only open beyond 1 bar operating pressure and flow rate changes in line with pressure increases.
That means operators simply enter a new application rate on the sprayer control system to change from one rate to another when moving from one crop to another.
Individual port feeds eliminate the risk of uneven flow from the bar when working across a slope – an acknowledged shortcoming over the cavity-bodied Streamer – and reduce the weight of the bar by half compared with the current design.
Liquid fertiliser stream nozzles
Agroco Umbrella fertiliser nozzle in three sizes, each with three metering discs, for 100 to 1500-litres/ha at 0.5m spacing. Horizontal outlets produce seven liquid streams of equal volume in asymmetrical pattern.
Albuz EXA three-stream (1.5 to 4 bar) and ESI six-stream (1 to 4 bar) fertiliser nozzles with ceramic orifice available in seven sizes from 015 to 06.
Hardi Quintastream available as complete nozzle or as tip for snap-fit body produces five liquid streams at different angles and flows – highest flow from centre, lowest from outer overlapping streams. Nine ISO colour-coded sizes from 015 to 15 with 1.5 to 5 bar operating pressures.
|Hypro’s ESI nozzle has angled outlets producing six solid streams of liquid.|
Hypro-EU ESI with vertical outlets producing six slightly angled liquid streams. Available in six sizes from 04 to 15 to handle volumes from 55- to 2078-litres/ha at 1 to 4 bar operating pressure.
Lechler FD angled flat-spray nozzle in seven sizes from 04 to 20 Nozzle as one-piece item to fit standard bodies or with adapter for Lechler Twistloc (Amazone) and Rau, Hardi. Lecher FL with five horizontal outlets from steel or plastic body and five stainless steel dosing discs; 1 to 5 bar operating pressures depending on orifice size. Tube Drop assembly for placing FD or FL nozzles within crop at 0.5m spacing; Hose Drop “T” bar assembly with dosing discs for surface liquid placement at 0.25m spacing.
|Triple stream output from TeeJet’s StreamJet SJ-3 nozzle.|
TeeJet StreamJet SJ-3 tip with removable metering orifice to fit Quick TeeJet cap produces three solid streams of equal velocity and capacity from vertical outlets in 10 sizes from 015 to 20. StreamJet SJ-7 tip with removable metering orifice uses horizontal outlets to produce seven liquid streams for overlapping application pattern; nine sizes from 015 to 15.
Liquid fertiliser dribble bars
Bateman Engineering: Accu-Rate four-outlet 0.5m plus three-outlet body with flexible remote orifice for boom hinge areas, etc. Individual port feed and key-adjusted flow rate setting mechanism with four positions. Joining links available to prevent twisting.
Billericay Farm Services: Streamer 0.5m bar with four outlets from open-cavity tubular body and five flow restrictor settings positioned using rotary dial. AutoStreamer bar with four individually-supplied outlets across 0.5m width fed via pressure-adjusted flow rate control valve allowing in-cab application rate control. Hook end body for ‘rubber band’ anti-twist links.
|Billericay’s Streamer fertiliser dribble bar has a five-position fingertip rotary rate selector.|
A six-position sliding flow restrictor is used on Chafer Machinery’s Streambar MultiRate.
Streambar MultiRate in 0.5m and 0.33m sizes with six-position slide rate setting mechanism. Four-outlet body with individual port feed; available with Chafer or EF3 bayonet nozzle body fittings.