Over the years a great deal of work has been directed towards improving the selection, testing and evaluation of biological control agents for weed control. This publication is one of a suite of 13 produced as part of a folder showcasing research from the Defeating the Weed Menace Research and Development program.

This edition of RipRap looks at the benefits that landholders can gain from managing their riparian zones as part of a total farm system. It also examines the work that is being done by Gary Brierley and Kirstie Fryirs on identifying the 'recovery potential' of a particular reach of river or stream. This work enables us to focus attention on those parts of the river and riparian zone that will respond best to rehabilitation activities. The result is that Gary and Kirstie's work can be used by landholders to identify and develop cost-effective river and riparian management strategies that will reap optimum ecological and economic benefits.

This fact sheet summarises the work Dr John K. Scott and his colleagues have completed using computer modelling of both plant characteristics and global climate change to predict how 41 of the nationally recognised 'environmental alert' species and agricultural 'sleeper weeds' are likely to behave as the effects of human-induced climate change become more apparent. It is now scientifically accepted that Australia's climate is changing and that these changes will continue over coming decades. Some weeds previously identified as either agricultural 'sleeper weeds' or weeds on 'environmental alert'* are likely to spread as a result of these changes in climate. This publication is one of a suite of 13 produced as part of a folder showcasing research from the Defeating the Weed Menace Research and Development program.

This update outlines design criteria for filter strip width to trap sediment and attached nutrients, and to accommodate typical soil losses from hill slopes.

The potential contribution of surface and ground water to overall nitrous oxide emissions from irrigated production systems has not yet been quantified. In this study we have used the International Panel on Climate Change (IPPC) emission factor five (EF5) to determine the indirect emissions from the irrigation water surface and from the ground water when it is pumped back onto the surface for irrigation. The additional land surface emission from the irrigation water source N was also calculated and termed the “indirect land surface emission”. The study primarily used data collected (2000–2010) from the Australian Cotton Research Institute, Narrabri, Australia to calculate indirect and direct farm emissions during the cotton production season from the research station. The average annual direct and indirect N2O-N emissions are 0.90 kg N2O-N ha−1 yr−1 direct; 0.30 kg N2O-N ha−1 yr−1 indirect emissions from the land surface; 0.08kg N2O-N ha−1 yr−1 from the head ditch; 0.03 kg N2O-N yr−1 from the tail drain. In total 26% of the emissions could be potentially emitted via the indirect pathway at the farm scale using river water for irrigation. If ground water with a concentration of (1.0 NO3-N mg L−1) was used to irrigate the crop then in total ∼1.4% of the emissions would be emitted via the indirect pathway at the farm scale. But further refinement of the indirect emission factor and improved monitoring of temporal and spatial surface and ground water total N concentrations are required for mass balance calculations. Direct measurement of the N2O-N water surface emissions is required to validate the IPCC calculated values

Discusses irrigation in Australia in the context of global food security, decreasing water resources and the contribution of research and development to innovation.

Over the past two hundred years we have physically and biologically degraded many Australian streams. Catchment managers at the end of the millennium face two daunting tasks: how to minimise further damage to rivers and streams, and how to repair the damage that has already occurred. We can return natural values to our waterways. This manual is designed to help those professional managers who are accepting the challenge of rehabilitating the physical and biological condition of Australian streams.

This report aims to summarise current and proposed GMO activities and make suggestions on targeted research investment that might better prepare Land & Water Australia (LWA) to help manage these new resources. This is despite the obvious limitations of trying to foresee the implications of such a new and broadly applicable form of technology.

On the whole, this research project showed that Australian farmers are alert to new weeds, and have a reasonably high level of commitment to their detection and control. As a group, farmers therefore need to be encouraged, and equipped to be vigilant and effective weed spotters. This may be achieved through training opportunities, greater extension and educational activities, increased resources devoted to weed detection, and greater cooperation between landholders and weeds authorities.

Stopping seed-set on weeds that have survived a treatment of glyphosate is an important part of an IWM approach to preventing the development of glyphosate resistance. The double knock method of seed-set prevention to avoid or significantly delay the evolution of glyphosate resistant ryegrass has been used successfully in southern Australia. The double knock tactic involves the use of sequential knockdown herbicide applications from different herbicide mode of action groups. This method has been developed so that survivors of the first herbicide application are controlled by the second