Despite the increased adoption of pressurised irrigation systems in recent years, furrow irrigation is and will remain to be the dominant application technique in the Australian cotton industry in the foreseeable future. Furrow irrigation involves relatively low capital investment making it ideally suited to the opportunistic nature of cotton production where the area planted varies from season to season depending on commodity prices and water availability.
The Australian Cotton industry can stake the claim of being one of the leaders in irrigation practice and innovation. Nowhere is this more apparent than for surface irrigation where the industry has made significant gains in water management leading to direct increases in productivity. One key driver of this change is the ability to monitor and model furrow irrigation provided through the use of the Irrimate™ in field evaluation system. Over the past decade, hundreds of evaluations have been performed in order to guide individual growers and inform researchers. The resulting data resides in the archives of each of the parent government institutions and consulting firms. The data recording and reporting processes are inconsistent between organisations and often also between individuals. Consequently it has been difficult to perform industry wide benchmarking of water use management.
Each organisation has adopted unique ways of analysing, and archiving field data, resulting in large quantities of data with limited hope being able to conduct industry wide studies. The Cotton Catchment Communities CRC and National Centre for Engineering in Agriculture (NCEA) have developed a web database, the Irrimate Surface Irrigation Database (ISID) with the following aims:
1. To allow the industry to benchmark the performance and potential performance of furrow irrigation
2. To provide added value to the process of irrigation evaluation where growers will be able to compare practices with others
3. To collate the large quantity of field measurements and evaluations that have been conducted over the past decade, a valuable source of information for future research in irrigation management.
Once completed, ISID was populated with data collected from all major catchments across NSW and QLD where cotton is grown with measurements stretching from the 1998-1999 to the 2011-2012 seasons. In excess of 630 separate irrigation events have been collated to date each with full field measurements, performance estimates and optimisation strategies.
The data capture and transfer process has been streamlined by integration of the database into the software model SISCO used during the evaluation process. This will ensure that the database is maintained and updated into the future. ISID also functions as a means to standardise and archive evaluations, a major shortcoming identified during collation of historical data.
Preliminary results from the database indicate that measured application efficiency across all seasons and districts is approximately 64.6% or 76.1% when accounting for tail water recycling. Optimisation of inflow rates and cut off times to improve irrigation performance results in an average water saving of 0.155 ML/ha per event. The design of ISID also enables users to interrogate the database in order to summarise the results according to criteria such as catchment, season, soil type and field length adding further value to the benchmarking process.
While individually the evaluations have been useful to growers, combined these results provide a valuable resource to the industry as a whole. The previous project failed to capture datasets across the industry due to (i) the limited amount of time available and (ii) the time required for manual data preparation and entry.
