Farmers' Newsletter No 180, Autumn 2009

• Research has been conducted over many years to investigate the potential of double cropping systems – however there has been little adoption of the practice in northern Victoria or southern NSW
• Issues such as stubble management, harvest and sowing conflicts between summer and winter crops, and the best combination of winter and summer options were identified as barriers to adoption
• A ‘double cropping’ project was instigated in 2006 to target these barriers and better understand them or resolve them through field trials
• There are also many opportunities with double cropping and the results from the project have been highlighted in a best management practice guide, which will hopefully see a greater uptake of this farming system

Results from Kerang trial block 2008 (475 k)

• Pre irrigation was vital to the success of the irrigated cropping trials in 2008
• The move to sow canola in April has paid off again with the trial averaging over 4.0 t/ha
• Cereals can be sown for grazing without impacting on grain yields if managed correctly and all cereals can produce similar quantities of fodder

• The bread wheat trial at Griffith achieved average yields of 10 t/ha in 2008
• Twenty five triticale and two durum lines achieved over 10 t/ha at all trial sites in 2007and 2008
• Twenty seven named bread wheat varieties, 457 breeders’ lines and 21 international lines achieved over 10 t/ha at either Yanco, Coleambally or Griffith in 2008
• Key traits of lodging and maturity did not have large effects on yield in 2008

• Limited allocations have made decisions on the most profitable use of irrigation water very difficult
• Farmers who watered wheat in spring were often surprised by the high water use or lack of yield response
• A review of some irrigated wheat trials and methodologies showed that the response to spring irrigation was between 1.0 and 2.0 t/ML

• A range of new irrigation technologies was showcased to irrigators in the Murrumbidgee Valley at field days organised by the IREC Irrigation Technology Subcommittee – keep a look out for more fields days in 2009

• Developed in the Riverina in the 1990s, bankless channel irrigation systems were designed to improve water management and production performance in rice-based farming systems and are now used for row crop production in many parts of Australia
• Evaluation and optimisation of water application efficiency is a well defined procedure for most surface irrigation systems – however they cannot be applied to bankless channel systems
• Research at Griffith seeks to develop an evaluation method for bankless channels, which then enables design and management guidelines to be established to assist designers and irrigators optimise the performance of current systems and improve the design of new systems

• The delaying of permanent water resulted in reduced water use, but whether water productivity ($/ML) is increased will depend on grain yield
• Any financial benefit from delaying permanent water will be determined after grain harvest
• Research into nitrogen management and greenhouse gas emissions of the delayed flood practice is necessary

• Fast watering will best suit soils suited to border check, paddocks with high water use that can’t be explained by run-off losses, and frequently irrigated summer crops and pastures
• In rice layouts, decreasing drainage times will have a far greater effect on reducing deep drainage and improving irrigation efficiency than increasing supply flow rates

• The performance indicators for water efficiency in cotton growing are generally not well defined and calculations have not been standard across the industry
• A study of 36 farms has been analysed and some useful benchmarks established for comparison of water use between farms and regions, and across seasons
• The most meaningful water use index for comparing irrigation water use was gross production water use index (GPWUI), as it relates total production to the total amount of water used – the average industry GPWUI was 1.13 bales/ML
• Based on performance indicators of the ‘top’ 12 farms (on the basis of crop water use index) it was calculated that under best management practice cotton growers across the industry should be targeting a GPWUI of 1.39 bales/ML

• The Environmental Champions Program has provided irrigators with support and streamlined access to information important to irrigation farming businesses
• The program has also demonstrated to the community, decision makers and green groups that irrigators are proactive and responsible managers of the natural resources on their land

• A project targeting rural women has provided training and information sources to help them participate in their own farm businesses more fully and to contribute to a more environmentally sustainable region