Hose reel irrigation, in ongoing evolution

What is called the hose reel system is the type most widespread in Italy for full field watering. Manufacturers in the sector are marketing more efficient solutions built not only for achieving excellent irrigation but also for optimizing such features as the pumps, hose wrapping, hydraulic servo control systems and central processing unit control

Time was needed but the concept that water is a precious asset to manage with great care has brought everyone into agreement. Within the general concept of sustainability the so-called water footprint is an indicator of direct and indirect water consumption, or the producer of the asset or service, and calls for singling out strategies for reducing it. The world of agriculture is strongly involved in all the components of the water footprint and as a result irrigation techniques and manufacturers of equipment for carrying out these operations have been aiming for some time to optimize water distribution for the purpose of limiting loss and especially waste. 

Among the solutions for sufficient full field watering, hose reel irrigators have been in the lead for a long time. These systems are made up of components for the mobile distribution of water with overhead spraying using flexible hose in polyethylene which is wound and dragged out on a high drum, that is, the reel on a traveling cart or trolley. A pump lifts the water and provides the pressure needed for spraying at up to 10 bar. Initially, the drag hose is pulled behind the cart moving along the irrigation lane with the sprayer components and then slowly reeled in when enough water is moving through the system.

The heavy hose can be pulled in with the use of an hydraulic turbine, hydraulics with an engine, an electric linear motor or hydrostatics with an independent internal combustion engine. To guarantee uniform irrigation or programmed distribution of the amount required the speed of pulling the hose in must be continuously managed by mechanical or hydraulic devices which often operate automatically. The most advanced models are equipped with many automatic operations which include limiting a fall in the pressure in the turbine, stopping rewinding at the end of a run with a drain valve for the adduction of the hose or disengaging its movement and emptying the main conduit with a compressor to lessen traction for the next time the host is reeled out. Moreover, a swivel can be installed for rotating the reel 180° to irrigate speculative plots without shifting the cart. Other functions are under hydraulic control, also via radio. These include lifting the front wheels of the tractor, setting the machine on the ground while hitching it to the tractor, lifting the traveling cart and the like.

 

Pumps

For bringing up water and providing the pressure required there are various types of pumps and solutions driven by internal combustion engines, almost always diesel, with power of up to 200 Hp for the top performance models. These motor pumps can be mounted directly on the frame of the traveling reel cart or operate as independent units installed on a trolley to facilitate road transport. The machines are also almost always equipped with computer processing unit (CPU) management control of the various functions, also by remote. The most high performance models are equipped with a manual or electric motor water abstraction system which is enclosed to soundproof the entire group.

 

Retracting hose

Hose diameters range from 30 mm to 160 mm and, in relation to their thickness, the modern material used for them is polyethylene which ensures the optimum characters of elasticity and resistance to dragging and wear for excellent use on rough and abrasive surfaces.

The mechanism for pulling them out and in is a key component on the hose reel irrigator because the uniformity of water distribution, reducing load loss, the accurate regulation of the speed of pulling the hose in, folding the sprinkler booms and the resulting precision of the water meter all depend on this operation. The mechanism is made up of an engine drive for turning the reel and a mechanical reducer with variable speeds to enable the speed of the operation to be modulated. Some time ago, technological developments began targeting better systems for retracting the hose to increase efficiency by reducing the power necessary for the operation and working correctly even with relatively low pressure, down to 2 bar.

In this connection, OCMIS in Castelvetro near Modena markets a chokeflow turbine perpendicular to the inlet with a built-in bypass to reduce loss of load to a minimum and correctly manage the wide range of speeds even with a low load and very low pressure. The turbine impeller is mounted directly on the shaft of the gearbox to give a wider speed range even when the inlet flow and pressure of the machine is low. The oil-bath gearbox shaft is tempered, cemented and rectified. The drum is mounted on bearings hermetically sealed, waterproof, requiring no lubrication and wear resistant. 

Watering terminals

Maximum versatility with a lance on an oscillating boom is achieved by the option to replace the mouthpieces to obtain the atomization most suitable for the water flow in relation to the characteristics of the soil and growth stage of crops. On the other hand, sprinkler booms and irrigation bars have the advantage of operating a low pressure to save energy by up to 50% compared to the long jet lance. In fact, new sprinkler booms in galvanized steel or aluminum are capable of coverage at distances of up to 50 m with each pass while optimizing the atomization of the water.

 

Hydraulic servo control

The application of hydraulic movement servo mechanisms on reels has make it possible for the operator to easily manage the machine, often by remote control via ratio. Examples are opening the traveling cart gate and/or raising the irrigation bar for changing location, rotating the swivel supporting the hose, placing and anchoring equipment and placing the suction pipe on models with a pump.

 

CPU management and control

A battery powered CPU sometimes integrated with a photovoltaic solar panel makes it possible to complete automation of irrigation operations beginning with control of flow and the speed of work on to programming the timing for beginning irrigation and finishing for correct watering without moving the components. Among the various solutions offered, Casella markets the Hydro-Control 260 CPU, which can be equipped with a GSM module. This means the computer can regulate the starting watering time without rewind and opens and closes the water flow to carry out watering in the correct way and change the pre-programmed parameters during watering. Moreover, the Hydro-Control provides a switchboard start key for functions which include total monitoring of the parameters and the performance of the pump. For fertigation, another CPU is available for injecting liquid fertilizer on the pump suction and allows splitting the doses to avoid losses.

 

Arrangements for road travel

Ensuring the required mobility of the equipment coupled to a tractor for towing is fundamental. There are single axle trolleys and those with two close axles for heavier models so care must be taken for the design of the equipment as regards road travel, care for the distribution of weight, for making certain that the drawbar conforms to the hitch eye, for the brakes and lights and visual signals and so on.

 

 

Durability and mobility

A considerable investment is required for the purchase of a hose reel irrigator, especially a high capacity model, so the intention is to have a machine guaranteeing efficiency over time and especially one which can be transferred on the road and public highways. The mechanical, hydraulic and electronic components of a hose reel irrigator are mounted on the frame which must be treated to ensure long term resistance to corrosion, a consideration to take note of because of the typical field of the machine’s operations, dealing continuously with water and sometimes also slurry.

For this reason, painted surfaces are usually given treatments which begin with pickling of the steel, followed by a double coat electrostatic painting job, which provides excellent covering even of the most hidden parts and involves a modern base treatment and water based ecological finish. Each step is finished with baking, normally at 60°C to guarantee great resistance to corrosion and UV rays.

For travel on public highways a hose reel irrigator must have type-approval, that is, be equipped with all the components necessary named in the Highway Code of laws and European Union Directives for trailed agricultural machinery.

Starting with what is needed for coupling the machine to the tractor is a drawbar with an eye hitch which can be regulated for height for correctly hitching it to the tractor. The drawbar itself, mounted on the main frame, is usually built with welded tubular steel supported either by a single axle or two close axles with tires which may have wide treads to reducing compaction during transit in the field. For this purpose, RM Irrigation Equipment in S. Quirico Trecasali, near Parma, markets an asymmetric rocker axle to reduce the force of towing on difficult terrain and guarantee the best distribution of weight in steering to facilitate maneuverability. Nitrogen suspension is mounted on some models to absorb shocks on irregular terrain and reduce roll of the machine in transit. Due to the considerable weight and open construction of these machines they are often equipped with hydraulic or air brakes which provide greater efficiency than mechanical brakes and, above all, can operate automatically in synchrony with the tractor. Another item of equipment often mounted is soundproofing of the pump, if there is one, as a useful option for reducing noise levels if the irrigator is operated for long periods in the vicinity of populated areas.

Accessories

There is an extremely range of accessories for hose reel irrigation covering practically all the main components of the machine. For starters there are various versions of the traveling cart carrying the lances or oscillating sprinkler booms to be adapted for the best watering practice. For the Turbocar series manufactured by Idrofoglia in Lunano, in the Pesara Urbino province, various versions are offered with under-foliage and over-foliage irrigation adapters, for offset axis movement or high pressure distribution, a water ballast tank and wheels in cast iron.  

 

Fertigation with umbilical system

Fertigation is certainly not a new practice as is suggested by the term which combines the fertilization of crops with organic or mineral liquid fertilizers and taking advantage of the medium of irrigation water.

The strong development of biogas plants in recent years has resulted in a problem for distribution of slurry in the field derived from anaerobic digestion which is an excellent organic fertilizer. The separation of liquid from animal waste solids calls for different techniques for spreading in the field.

The liquid part is increasingly applied with fertigation, often using the umbilical system, that is slurry mixed with water in various concentrations buried directly in the soil by flexible tubes towed by the tractor and then worked on the surface or at depth. The slurry can also be used for top-dressing crops by bars or boom applicators fitted with nozzles or trailing-hoses operating from tramlines. The hose reel irrigator often manages the application of slurry by winding and successive unwinding.

Supplying slurry can be done with the use of underground pipes installed for the purpose or, if the plot to be fertilized is a long distance from the farm, by the use of tanks for temporary storage while the operation can be performed with great continuity to ensure the timeliness of the job and time saved.