How to get the most from your WSFs

3 mins
Peter Robinson
ICL OH, Technical Area Sales Manager

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    Delivering fertilisers through irrigation, fertigation can be a powerful and efficient tool for managing crop health and performance. In ‘Feeding success’ part 2, ICL Technical Area Sales Manager Peter Robinson explains how to get the best from your equipment.

    Saving time while improving precision

    Crop fertigation involves preparing a concentrated fertiliser solution in a stock tank and introducing it into the irrigation stream using an injection or dosing system. When applied correctly, growers save time and benefit from improved precision compared to traditional methods.

    Nurseries typically rely on three types of system:

    • Venturi-type injectors, such as Mazzei- water pressure differentials draw fertilisers into irrigation line
    • Water-powered dosing units, such as Dosatron – highly versatile and widely used. Integrated into fixed pumping systems, deployed at remote nurseries, or connected to hose pipes for localized feeding (See below for tips on use)
    • Computer-controlled systems, such as Heron – precision automation and monitoring capabilities for large-scale operations.

    Effective mixing and nutrient solubility

    When choosing a Water Soluble Fertiliser (WSF), select a product that dissolves readily in water and stays in precipitation for as long as possible.

    WSFs can be either ‘straights’ which are mixed, liquid feeds or blended products aimed at specific crops, or nutritional, requirements.

    Top Tips: Agitate – particularly when cooler

    The stock solution needs to be well mixed for application. Consider agitating for a few minutes prior to each fertigation cycle– particularly if using cooler borehole water. Use air from a blower or compressor, via a manifold in the stock tank, or recirculation via a suitable pump (eg in stock tank). These can be set on a timer or linked to irrigation timers.

    Which product?

    When choosing a WSF, factors such as compatibility between different straights and blends, plus maximum solubility, should be considered to avoid precipitation issues and undissolved product.

    Depending on your crop, and specific nutrient requirements, ICL offer two WSF ranges – our standard, value Universol range and our advanced fertigation Peters range.

    100% water-soluble, our premium quality Peters products are popular with growers of high value crops, such as Poinsettias and Orchids, and those relying on water with a high conductivity (EC).  Featuring our M-77 chelating formula, ensures all nutrients and trace elements remain fully available for rapid root uptake.

    Top Tip: Check water conductivity (EC)

    Check the EC regularly, particularly when making up a new stock solution. Changes in water supply can lead to differing EC levels, as will errors filling the stock tank or adjustment of the dosing rate! Pick these up with a quick EC check – remember to calibrate your target EC relative to the feed strength required.

    Cautionary tale!

    Growers sometimes use more than one stock tank – applying different feeds through a common irrigation system or to individual production areas.  Mix ups can result in the wrong WSF being applied. It’s a good idea to have a written protocol with checklists for replenishing the stock solution tanks.

    Get the most from your Dosatron – tips courtesy of Kris Jessiman (Hingerose)

    Flow Rate Check

    Use the flow rate calculator for popular Dosatron models to verify if your unit is performing efficiently. This is helpful when you know your pump’s flow rate or can work it out for a valve section. If flow rate is lower than expected, the unit may need maintenance. For new units, this tool helps confirm proper pump performance.

    Maintenance and end-of-season tips

    • Rinse the unit after use – especially with aggressive chemicals or powders.
    • Drain the unit if it won’t be used for a while, especially if stored outdoors.
    • Protect from temperature extremes – particularly freezing.
    • Install a filter before the unit (based on water quality) to prevent abrasive wear.
    • Inspect and maintain the unit regularly.
    • Dosatron recommends replacing seals every 12 months, but actual intervals depend on frequency and duration of use, water flow rate and quality and the type of additives used.

    Most routine maintenance – like seal replacement – can be done by growers, possibly with help from their irrigation supplier or Hingerose’s technical team.
    For more complex repairs, units may need to be returned to Hingerose for evaluation.

    For help devising a season-long water-soluble programme for your crops, or for correcting a deficiency, speak to your ICL Technical Area Sales Manager.