Tuesday 8 September 2015

Variable Rate Irrigation Pioneers

Ashburton cropping farmers Eric and Maxine Watson (Rangitata Holdings) were the South Island’s original Precision VRI pioneers. Ordering four VRI systems in 2008, after only two systems had been built and tested less than twelve months earlier, Eric and Maxine took a lot of trust and belief that the system would achieve what Precision Irrigation claimed.

This 3 News clip has been bought out of the archives from 2008. Eric and Maxine Watson along with Stu Bradbury, one of the engineers who developed the technology, showcasing the first system up and running in the South Island. And the results exceeded their expectations. The Watsons now have seven out of their nine lateral-move irrigators fitted with Precision VRI. 

The Watsons farm 490 hectares on the Canterbury Plains, with annual rainfall of 600mm, growing a wide range of crops on different soil types. In 2005 Rangitata Holdings water right restricted their annual and daily water take, so they started looking for ways to stretch their available irrigation water. With an annual water volume of 1,183,500m³, 3.7mm per hectare per day and 5ha of irrigator overlaps, VRI was considered as the solution to save water where it was being wasted. An unlooked-for advantage was the negated need for turning taps off and on when watering in pivot mode.
At least partly as a result of maximising water efficiency, and being able to prove minimal wastage, ECan raised the Watsons’ annual water volume to 1,420,000m³, 4.1mm per hectare per day. This consent only permits pumping 270 litres per second across all pumps. When one irrigator is watering in an over-lap situation or using different rates over different crops, they are able to use the saved water to turn on another smaller irrigator elsewhere on the property, thus ensuring soil moisture levels are maintained at critical times.

“It’s a great system with a big future... Now that I have VRI, I wouldn’t want to run the machines without it.”

Caption: Eric and Maxine say that the Growsmart Precision VRI system exceeded their expectations allowing them to maximise the use of their limited annual water volume allocation.

The couple’s dedication to efficient water use has seen them recognised with numerous awards including the 2011 Canterbury Ballance Farm Environment Award and the Environment Canterbury Water Efficiency Award. The Watsons say they were just doing what was needed to get the best out of their limited water take. Once they identified the greater efficiency with Growsmart Precision VRI, the opportunities snowballed. 

Eric and Maxine had the property electro-magnetically (EM) mapped and the soil water holding capacities quantified. Soil moisture sensors were installed to measure the actual moisture content of the soil. This allows the Watsons to schedule the correct amount of irrigation to individual zones which is then applied by the intelligent Growsmart Precision VRI system. This results in the crops getting the exact quantity of moisture required and no water is wasted. Resulting in a considerable saving of 15% of water that can then be used elsewhere.

"Being able to match application rates to the exact amount of water needed to ensure the soil has enough moisture is important to water efficiency and means that over-watering of crops is eliminated."

For More information contact your local Zimmatic by Lindsay irrigation dealer or visit growsmartprecisionvri.com.