NSW Department of Primary Industries aims to develop and introduce efficient and environmentally sustainable methods of agricultural practice for Murray Valley farmers through a Participatory Action Research approach. Staff at the Deniliquin Agricultural Research and Advisory Station work in partnership with the RIRDC Rice Research Committee, Murray Irrigation Limited, the CRC for Irrigation Futures, the Murray Land and Water Management Plan and district farmers. Research is concentrated on farming systems and agronomy with an emphasis on improving water use efficiency.

Irrigated Farming Systems

A series of discussion groups and field trips initiated by NSW DPI’s research and extension staff has assisted district farmers to identify the need to find more profitable and sustainable farming systems. A number of sites have been offered for long-term on-farm experiments while short-term demonstrations are located at Murray Valley Field Station. Trials have begun with the goal of assessing, comparing and improving whole farm water use efficiency in five key areas:

• irrigation and water management
• soil management
• rotations
• stubble management
• in-field crop variability 

Farming Systems Comparison – Deniliquin and Moulamein

Three farming systems are being examined over a number of years on two properties in order to find the most sustainable and profitable crop rotation. The standard 1 in 4 rice/wheat/pasture rotation is being compared with a 1 in 4 rice/winter cropping rotation and with a winter cropping only (excluding rice) rotation. Controlled traffic, conservation tillage and stubble retention practises are being applied where possible.

Soil and Stubble Management

Soil health and crop yields are the criteria against which the questions of burning or retaining stubble, adding biological soil ameliorants, adding gypsum, or cultivating are being assessed.

Centre Pivot Irrigation - Crop and Variety Evaluation

Wheat, barley and canola grown in rotation under pivot irrigation will enable data to be obtained of water use efficiency and profitability between crops and between varieties.

Agronomy

Wheat crop being grown as part of the crop rotation study (photo: C. Parks)

Improving Water Use Efficiency of Rice

The cost of irrigation water accounts for 20-30% of the total variable costs of rice production. Research elsewhere indicates a reduction in water use when rice is grown on a raised bed layout rather than using conventional permanent flood. When tested in the Murray Valley, even though water use was reduced by 14%, grain yield was also reduced by an average of 10% compared with yields from permanent flood. Other water saving strategies, including intermittent irrigation prior to panicle initiation and mid-season drainage are being investigated. This work links closely to research on landforming and soil infiltration.

Rice Breeding and Physiology

In temperate regions, rice yields and quality are high and the incidence of disease relatively low due to dry summers, high solar radiation and cool temperatures during the ripening period. NSW DPI’s rice breeding program, with the support of rice growers and the Australian Government through the Rural Industries Research and Development Corporation, conducts trials throughout the Murray Valley each season to evaluate impacts of regional differences in climate and soil types. These trials have contributed to the release of fifteen rice varieties for the NSW industry since 1987. Ten of these varieties are still grown commercially and are responsible for more than 95% of NSW production.