MAF Sustainable Farming Fund trials, headed by Carolyn Hedley of Landcare Research, aim to compare the irrigation water use efficiency for uniform rate irrigation (URI) to variable rate irrigation (VRI) at three trial sites over two irrigation seasons (2011/2012). The trails are being run at Tahuna (arable/livestock) in the Rangitikei, Rangitata Holdings (arable) and Wainono Dairy Partnership both in the Canterbury region.
Season one results of the improved irrigation water use efficiency trials indicate sustained crop and pasture yields under reduced water usage is achievable with a VRI Precision Irrigation system.
The VRI system allows irrigation to be controlled to meet the requirements of the different soil zones. Therefore water can be saved where it is not needed, also saving money through reduced pumping costs.
Hedley’s goal is to validate desk top studies indicating 15-20 percent irrigated water and associated pumping cost savings through the implementation of a VRI system without detriment to crop yield or milk production.
Comparison trial plots were carefully chosen at each site to represent comparable growing conditions including soil variation and crop/pasture management practises. The three trial sites have been EM (electromagnetic) surveyed to characterise the soil variation under each irrigator. The available water holding capacities (AWC) for the different soils were then calculated by ground-truthing the EM survey results. Irrigation plans for the VRI zones were created using Precision Irrigation’s VRI programming software. Water meters were installed on all the properties to log water use. Yields were assessed through a combination of yield mapping and hand harvesting.
The 75ha Rangitikei trial site consisted of excessively drained sand to imperfectly drained loamy sand areas. Variation was divided into three zones. Using VRI to irrigate to the variation in soils and keep water out of the drains produced water and pumping cost savings. Yield difference from VRI and URI trials was statistically insignificant. Hew Dalrymple, owner of Tahuna, was pleased with the results as previously the trial site was producing up to 4 tonne/ha less than his best crops. The extent of soil variation creates a huge challenge to set optimum URI rates across the crop, VRI eliminates this problem.
Tahuna trial site in the Rangitikei, crop variability issues (left) and irrigation management zones for the 2010/2011 irrigation season (right)
The 174ha irrigated area at Wainono Dairies was divided into four zones based on variability in soils, water was able to be saved in areas where over-watering typically occurred. Pasture production was measured using a C-Dax pasture meter and was not compromised with the reduction in irrigated water.
Rangitata Holdings near Ashburton grew wheat and beans under one of their lateral-move irrigators which was assessed for the purposes of the trial. The combination of Rakaia and Wakanui soils, including stony sandy loams and silt loams and contour of the paddock produces varying irrigation requirements across the length of the irrigator. Irrigation water use efficiency was improved in both crops through VRI, with a statistically insignificant difference in crop yield. If VRI water savings for the trial areas were extrapolated over the entire field, 1 million litres of water and associated pumping costs could be saved per day.
The results presented in this report are provisional, trials are to continue over a second irrigation season this summer. Further details of the trials and findings of the project will be presented through literature and a series of field days run at the various trial sites. The field day at John Wright’s Fairlie property is being run on the 16th of February, kicking off at 11am, visit the DairyNZ website for more details (Variable Rate Irrigation Field Day - Fairlie).
January 17th 2012
We are excited to announce that on the 3rd of November 2010 Lindsay
International (ANZ) Pty Limited acquired the business of WMC Technology
Limited, which included the trading divisions of Precision Irrigation and
Wheresmycows.com Farm Mapping.
The company will carry on operating as they have been, continuing to develop cutting edge farm mapping and irrigation products for the benefit of the farming industry. And, as always, will provide the high quality service which our customers have come to expect from us.
Call the team today on 0800 GET MAP (0800 438 627) for any enquires.
After only 5 years in business, Manawatu based company WMC Technology Limited which encompasses two trading divisions (Wheresmycows.com Farm Mapping and Precision Irrigation) emerged to take out three separate awards at the Manawatu Business Awards, held in Palmerston North on Friday 19 November.
The team's first appearance on stage to accept the New Zealand Trade and Enterprise Innovation in the Manawatu Award was shortly followed another appearance to receive the ACC Workplace Safety Award and then at the end of the night, the Westpac Manawatu Supreme Award.
WMC Technology started out as Wheresmycows.com Farm Mapping while directors Stu Bradbury and George Ricketts were studying engineering at Massey University. Since then, the company has grown to employ 7 full time staff (5 of whom studied together at Massey) and has taken on a further two summer students. Wheresmycows.com provides GPS and aerial photography farm mapping solutions to New Zealand, and exports their "Do It Yourself GPS farm Mapping kits" (which include a Garmin handheld GPS and Wheresmycows software) around the globe.
Under the Precision Irrigation banner, the team has engineered a Variable Rate Irrigation system which controls every sprinkler individually on a centre-pivot or lateral move irrigator to combat variability in soil wet and dryness under a machine that would otherwise apply a uniform amount of water everywhere. This control is based on the Wheresmycows.com Farm Mapping software and is becoming popular in New Zealand, as well as being exported to the USA, Australia and South Africa.
Straight Furrow December 7th 2010
The Precision Irrigation variable rate control system for centre pivot and linear move irrigators gives total control of where water is applied beneath the irrigator. With remote programming and monitoring through the easy to use software interface and an advanced system controlling every sprinkler on the irrigator, water is applied at varying rates only where necessary. Water and pumping costs are saved and the irrigator will run to maximum efficiency.
Feilding-based Precision Irrigation began developing a VRI system in 2006. The system went through various stages of design and testing until the first prototype was installed on a dairy farm in 2008 with the aim being to keep water off the cow tracks. Since then 12 VRI systems have been installed nationally.
The mapping software runs on farm PC and takes many forms of a farm map including maps drawn from GPS, aerial photography or Google Earth. The irrigator’s specifications are loaded into the mapping software and then the areas are drawn on the map and programmed for how much water they are to receive. A programme is then generated and loaded into the VRI controller on the irrigator with the irrigator using GPS to determine its position and using a wireless network of control nodes turns on, off, or pulses valves individually for every sprinkler.
More than 3000 pivot and lateral sprinkler systems have been installed in NZ since 1997, irrigating an area of about 300,000ha and Bradbury believes 30-50% of these centre pivot irrigators could be retrofitted with VRI to provide immediate economic benefit to the famer with potential water and power savings estimated to be 10-20% using VRI to address the variable soil types.
Precision Irrigation had taken the concept of VRI and produced a package that can be fitted at installation or retrofitted to any existing centre-pivot or linear irrigator. They are supplying VRI systems to irrigation installers and plan to continue the development of the VRI system while providing support to existing customers.
Traditionally, centre pivot irrigators have been a somewhat blunt instrument - delivering a uniform amount of water to the land whether it needs it or not. This has led to losses in both terms of production - crops can't grow in a bog - and unnecessary water loss. Now, a group of current and former Massey students are changing that.
Research by a Massey PhD student has helped a Manawatu company, Precision Irrigation, lanuch its variable rate irrigation system, which will provide farmers with the ability to precisely target their water use. Part of the system was devised by Dr Carolyn Hedley at the Centre for Precision Agriculture in the Institue of Natural Resources.
Her reaserch coincided with development work being carried out by two former Massey graduates Stuart Bradbury and George Ricketts. Their company, Precision Irrigation, has developed the system that can deliver variable applications of water under a centre pivot irrigator. The system incorporates more sophisticated control of the irrigator through a simple-to-use interface that can utilise the scientific knowledge created through the PhD research.
Water application is matched to the exact requirements of the soil. The system creates a detailed map of the soil that indicates the soil's ability to absorb and hold water for plant use. These maps often show that soil is variable so uniform application may be wasteful in many areas, while being insufficient in others. Hedley says that the soil's available water holding cpacity is derived from an electro-magnetic surveying method.
Centre Associate Professor Ian Yule says centre pivots have become the main method of irrigation because they are much easier to manage than other systems, but they are terribly inflexible. "You are very limited if you want to grow different crops under the same irrigator, simply avoid irrigation on non-productive areas under it, or respond to variations in water demand," he says. "What Precision Irrigation has done is produce a system that overcomes all these difficulties; add Carolyn's work to this and we now have a system that can match water application to variable soils."
Bradbury says, "Interest is growing, we've had feedback from farmers who have installed the system, one farmer saying it has saved him $50,000 in potential lost crop in just one season... Another dairy farmer, who installed a system worth $30,000 says he's saving about $10,000 a year."
Case studies indicate that not only does the system lower water use, it reduces drainage and has the potential to reduce leaching from agricultural land. "Variable rate irrigation can reduce a farm's water, nutrient and carbon footprints," Yule says. "It's a win - win, creating better financial outcomes while improving our environmental performance."
DefiningNZ field days 2010 (Not whole article)