Irrigation and Water FEATURES Management Principles

There is a universal trend that tends to happen when resources are plentiful, we seem to have the tendency of becoming complacent and we stop micromanaging our usage. I get it, we see no need to as the resources capacity is quite literally overflowing.

But can I take you back to four years ago, when our continent seemed to skip spring altogether? It was as if we went straight from winter into summer. As the first of September approached, we were reaching temperatures that often exceeded 35 degrees Celsius each day, wondering just who decided to leave Hades’ door slightly ajar?

It ended up being one of the hottest summers recorded in the history of South Africa. It was our sixth year going through the El Nino cycle – a documented period with above average temperatures – with an exceptionally dry season making most of the continent fare poorly and for those of us in the turf industry, faring even worse.

So, why write an article regarding water conservation when our weather forecast is looking so great? Simply put, now is the time where we need to remain habitual with our behaviour of conserving water. Each drop does matter. We need to be aware of some basic water managing principles, regardless of whether you oversee maintenance on a golf course or you are merely watering your own garden at home. It's hugely beneficial, making yourself aware of what techniques can be instilled, so that you can begin and remain a conserver of water.

To start, let's break it up into sections. This will make it easier to explain, and since the sections are also largely interconnected, you can understand that one cannot go without the other:

• Tools/equipment/material • Data recording • Programmes and planning

Gone are the days that we water our gardens making use of merely a sprinkler with the hosepipe connected to the tap, leaving it to stand on one spot for hours and forgetting about it while we watch the Saturday game.

What makes tools and equipment so important? Simply put, you cannot have a good programme in place if you do not also have the ability to manage it correctly.

Turf pitches and good landscape installations always start with a basic irrigation installation, one that is controlled by a computer. It could be as basic as a block system, controlled with solenoid valves opening four sprinklers at a time, or more advanced – using individual solenoid sprinklers that can be controlled individually. This is seen as a good starting point to manage water effectively.

Golf courses usually like to make use of block systems on their fairways and tee boxes and when it comes to their greens, they will have individual solenoids controlling each sprinkler for a specific area that might need more water than the others. This enables them to micromanage their water output. In order to control the output or usage of water, you would need an irrigation installation with permanently placed and well positioned sprinklers.

Satellite boxes with an average of 40 to 80 controllable stations (four sprinklers per station) help for effective time setting per station and enables golf courses or sport pitches to be watered at night when no-one is playing. This is obviously the most time efficient.

Not only do satellite boxes give you the freedom of setting times and controlling sprinklers at a specific time of the day, but you can now also connect your satellite boxes (four or five per golf course) up to what they call a central control system. The central system enables you to run more effective watering programmes from your laptop in the office, and this data can be retrieved by your phone. The central control system also enables you to connect to a weather station, and moisture sensors that are spread out on your course. This links to your laptop for more accurate readings, which in turn allows you more control over activating or disabling run times as the moisture readings take place in your soil profile.

If you can't afford one of these advanced systems and need stats to ensure that you have the right watering programme in place – one that is sufficient for plant uptake and spot

checks – you could make use of a portable moisture sensor in the garden or on greens. Moisture readings, in conjunction with calculating evapotranspiration rates weekly, is essential to forecast and planning. The take home is that to manage water, we need tools and materials to make it possible.

I say that data recording is important because to plan you need stats, without stats we cannot do any predictions, and without predictions we cannot plan and have effective programmes in place.

Water flow meters are probably one of the easiest installations to install that will give water usage reports per cycle. A simple way of monitoring total water usage is if you break up the watering into sections to establish how much certain sections use. For instance, if I need to know how much water I use on just the front lawn at an office block I manage, I can run a full watering cycle and take the reading. By doing this and breaking up the sections, you effectively increase your water management capabilities on the facility you maintain.

Another simple way of tracking water flow is sourcing your sprinkler and nozzle product info book, which will give you flow ratios and optimal working rate under bar pressure used. Quickly counting how many sprinklers you have with coloured nozzle sizes; you can then establish what your flow rate is per second. Do a quick calculation (sprinklers x flow rate x total time) and you now have your total use of water for the whole facility. Probably not as effective as having a central control system but this will still give you at least 95% accuracy.

We now have a good irrigation system in place combined with the ability to record usage of water, so now what? How do I plan for how much water needs to be put down and when? Working out a programme does not have to be tricky when you have all the above in place.

• Soil moisture.

• Type of plant used, and water needed for optimal growth. • Data of how much water you distribute in a specific timeframe. • Evapotranspiration rate (how many mm of moisture you lose per week via temperature). • Spot checks on leaks and if irrigation (pumps, sprinklers, satellites, solenoid valves) are functioning at optimal levels.

It is imperative to adjust your watering schedule daily, according to soil moisture readings and current heat/temperatures.

Evapotranspiration = Evaporation rate x crop factor rate of specific plant.

• Kikuyu evapotranspiration average daily rate is 4.41 mm/day (J D Jansen van Vuuren Turf Grass research). • Sprinkler x supplies with five bar pressure 13 mm/h with a blue colour nozzle (see sprinkler manual). • 13 mm ÷ 60 min = 0.216 mm/min • 4.41 mm/day (ET) ÷ 0.216 mm/min = 20.41 min/water

This means that an average of 20 minutes of water needs to be put back into the soil for plant uptake. This figure could be much higher as leaching/loss of available water is almost guaranteed. Rate of moisture uptake by specific plants also needs to be considered, but this is a discussion topic for another article all on its own.

Having the basic setup of a good irrigation installation is crucial to setting yourself up for a sufficient programme. Continual maintenance checks are also important. It is essential to ensure that the sprinklers are working, there are no leaks on the irrigation system, that the sprinkler settings are appropriate and that the arc circle is optimal. Weekly checklists, and educating employees on these matters, will determine a sustainable future with our water usage and conserve resources for the future.

Saving a little today can mean a lot for tomorrow.

By Henk Buitendach, general manager at Thatchfield Golf, Chairperson for the Turf Grass

Manager's Association of Gauteng and SALI

Gauteng regional judge.