School of Health, Medical and Applied Sciences (HMAS), CQ Univeristy, Rockhampton, QLD 4702, Australia

Speech Title: Hydrogen peroxide injection in irrigation water for improving the efficiency of drip irrigation
Abstract
Irrigated agriculture contributes significantly to global food security. Flood and furrow are common irrigation methods in the world, but are known to have poor irrigation water use efficiency (WUE). The WUE of irrigated agriculture must be improved because of the declining allocation of irrigation water due to competing demand for fresh water with industry, domestic and environmental use and also the uncertainty brought about by the global climate change impacting the water resources. The future access to irrigation water could be greatly affected in the arid and semi-arid regions of the world where the supply of irrigation water is already under stress. Alternative water resources such as treated effluents can be major target of irrigation water in such water limiting societies. Future irrigation methods, therefore, should be tuned for harnessing the use of low quality water.
Micro-irrigation methods, such as drip irrigation (DI) can be options both for enhanced irrigation WUE, and means for conveying poor quality irrigation water. In spite of recorded efficiency, drip irrigation system can regularly suffer from emitter clogging due to scales deposit, biofouling and root intrusion, which can greatly affecting the performance of drip irrigation. DI system is also known for developing wetting fronts exposing the rhizosphere to low oxygen environment. Therefore, optimization of drip irrigation is required in order to harness WUE in irrigation. Our research on optimization of DI and SDI with oxygation (use of aerated water irrigation), multigation (adapting oxygation with fertigation) and use of hydrogen peroxide shows improved irrigation uniformity through cleaning drip emitters of scales, biofoul, root intrusion and through aeration effect of rhizosphere enhancing the crop performance. We present results of continuous injection of low concentration of hydrogen peroxide products for enhancing irrigation efficiency and crops performance under different soil and water environments. We also present evidences for the mechanism of hydrogen peroxide actions that improve the oxygen delivery in the rhizosphere, control of scale and biofoul contributing to uniformity of drip emitter flow rate. The positive effects of low concentration hydrogen peroxide dosing in irrigation water resulted on improved yield and WUE under diverse soil and water quality regimes. We also highlight a need for collaborative approach and linkage bringing irrigation and allied industries, growers, researchers and technology transfer agencies together in R&D for impact oriented irrigation research.