Keytah System Comparison

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Keytah System Comparison

Keytah System Comparison

For five years now the Keytah System Comparison has been gathering comprehensive and insightful data to benefit the industry as a whole. Data collected over the following seasons, 2009-2010, 2011-2012, 2013-2014 and 2015-2016 has proven extremely valuable. The recent 2017-2018 season continued the trial with the incorporation of automation techniques in the bankless channel and the siphon systems.

This is a unique project run by growers with the specific intention to collect relevant commercial data. See why growers see this as important.
A key part of the project is to demonstrate innovation in irrigation and provide cotton growers greater insight into the four different systems under review; siphon, bankless channel, lateral move and subsurface drip.
In February each year the GVIA host a field day to give growers an opportunity to see the field activities of the project and to discuss the findings, get your copy of the 2018 brochure.

During the project, the Gross Production Water Use Index (GPWUI) was calculated for each of the systems. The GPWUI is used to enable a comparison of the systems across years and across farms. It combines total seasonal water use (irrigation water and rainfall) with soil moisture and yield. The higher the GPWUI the more water efficient the crop.


The most important finding is that the greatest differences in GPWUI and yield are between years, not between systems. Results show significant variation in the GPWUI between years principally due to climatic conditions. Each of the seasons have been very different, from cool and wet, to hot and dry, with one season where there was no irrigation or rainfall to finish the crop.

The 2017-2018 season has produced the highest yield for each of the four systems, this year the bankless channel system was the strongest performer with a yield of 14.8 bale/Ha and a GPWUI of 1.29 bales/ML. Both the siphon and the lateral also performed strongly with yields of 14.7 bales/ha and 14.3 bales/ha respectively.  The GPWUI results for both siphon and lateral were also good at 1.23 and 1.24 bales/ML.

The five year average has shown the lateral move to have the highest average yield and GPWUI.  The bankless channel had the second highest average yield and GPWUI.

The siphon field had significantly higher labour requirements, but along with the bankless channel it had very low operating energy costs. In contrast, both the pressurised systems, the lateral and drip, had high operating energy costs. These two systems also had high capital setup costs.
As labour resourcing is becoming more difficult, especially in the more remote areas the 2017-2018 expanded to evaluate the practical constraints of installation, management, reliability and suitability of automation of flood irrigation.
The siphon field was fitted with small pipes through the bank attached to Smart Siphons. Capital set-up costs  for the smart siphon will be significantly influenced by field specifications and installation process adopted. Details from the findings this year are being updated into a technical report and brochure which will be available on line in the near future.
In the mean time, the following links will take you to the 2016  brochure, the report and the video which provide more detail on the project.

During the 2017-2018 season the project trialled a telemetry and smart siphon management system managed with an EnviroNode Hub a platform developed for customisation. There was an ultrasonic wireless water level sensor installed in the head ditch and capacity for water advance sensors. The project also enabled the trial of a customised mobile device web App, which was provided initially with a display of current and graphed water levels, a display of the smart siphon system status and a capacity to download data. 

The project has shown that although important, water alone is not the only driver growers must consider when making decisions on irrigation systems. The reliability and the potential yield achievable under each of the systems are key considerations for growers. In areas where there is low reliability of water capital costs will be critical, as will labour resourcing, energy costs, maintenance and servicing. This project provides growers a detailed data set to inform their irrigation infrastructure investment decisions. 
The trial has been well received by growers and industry since its inception, with data continually enhancing grower’s capacity, knowledge and understanding of the efficiencies of alternative irrigation systems.

Many growers have altered their irrigation systems following a visit to Keytah, or from discussions with people involved in the project, which is an extremely pleasing adoption rate.

Making Every Drop Count

Securing a future for the Gwydir Valley through Irrigated Agriculture.