Seven C's for irrigation efficiency: care, cost, create

Caring for systems and being inventive about where the energy comes from is important when improving efficiency.

Even the best systems in the world with the most sophisticated control and monitoring will only work if someone cares enough to use them properly.

This is especially important with irrigation because automatic sensing and control can only take you so far. Good irrigation management will always require a generous measure of knowledge, experience and motivation to get things right.

The impact on energy may be important, but crop performance is the main issue here. A host of additional problems may be magnified through poor water management, including algae and pest-management problems, leaching fertilisers and increased disease pressure.

Individual motivation comes through training and good staff management to lead workers to understand the importance and impact of doing things properly.

Cost is not in itself an efficiency issue, but it drives the need for better efficiency and indicates the highest priority issues and those which, although desirable, might not be justifiable economically. It’s, therefore, important to analyse what improvements might cost and try to estimate what impact they might have on value and output. Only then can you derive a rational plan for improvement.

If systems can avoid the use of bought-in energy, then energy efficiency may no longer be quite as relevant.

Some examples of this might be:

• Where sites are hilly, water storage can sometimes occur at a higher elevation than the growing site, resulting in the head pressure of the storage being enough to drive the irrigation distribution system
• Use of solar and wind-powered pumps, perhaps in conjunction with gravity-fed systems, can provide the energy needed in the irrigation distribution system. Systems with gravity water storage take the time pressure off renewably powered pumps, so they can work when the solar or wind energy is available and effectively store the water pressure energy over an extended period