The theme of this edition of RipRap is looking at overseas research, knowledge and experience to see what help we can get for river and riparian management in Australia.

With recent advances in technology irrigators can now more precisely control delivery of mineral nutrients and water to the roots of perennial tree crops. These technologies, collectively referred to as fertigation, provide the opportunity to adopt and implement highly technical management programs, such as open hydroponics, that use drip irrigation to deliver a balanced mixture of nutrients and water. This research bulletin provides an overview of a project, funded by the National Program for Sustainable Irrigation, that aims to investigate some of the issues specific to using fertigation in Australia and work with irrigators to upgrade their knowledge and skills to maximise the new technologies.

Despite the widespread promotion and adoption of precision agriculture in dry-land cropping systems, the concept of irrigation being part of precision agricultural systems is still getting off the ground, both in Australia and internationally. There is currently no cohesive framework available to guide research, development or adoption of precision irrigation and its associated support technologies. This project is reviewing irrigation research, existing technologies and the use of precision irrigation. It will assess the role of current irrigation application technologies in precision irrigation, variable rate applications, adaptive control, and the sensing and decision support requirements. Opportunities for adoption and future research will also be identified. The first stage of the project - conceptualising and defining precision irrigation - is summarised in this research bulletin. Any feedback on this information would be gratefully received. The newness of precision irrigation means there has been very little discussion around the concept-and any research being conducted will certainly benefit from shared knowledge.

To achieve consistency in data sets and to assist in interpretation and comparison of results, at the beginning of this program, the Land and Water Resources R&D Corporation (LWRRDC) requested that common protocols be established for sampling, data production and reduction, validation and completeness, for use by the separate projects of the joint program. It was recognised that the methods of analysis vary slightly to suit local needs of each laboratory and project, but a common basis was necessary for assessment of data, to provide consistency and for valid comparisons to be possible. LWRRDC also requested that a Quality Assurance project (QA) be conducted as part of the Minimising the Riverine Environmental Impact of Pesticides R&D Program. Both the original recommendations for sampling and analysis and the results of the QA are described in this publication.

In season 2001-02, the Central Highlands area

of experienced Australia's

first major outbreak of Silverleaf Whiteny

(Bentsi" tobcci biotype B) in a cotton

production system. The situation was managed

to some degree with existing products, and

whilst there is no indication that the quality of

Central Highlands cotton was diminished this

season, the industry realised that advances

needed to be made for the effective management

of this pest in the future.

Two key factors that made management of

Silverleaf Whitefly (SLW) difficult in 2001-02

were a lack of suitable insecticides and knowledge

of the pest and how it would react in cotton in the

Australian environment.

To address the second issue, the Cotton Research &

Development Corporation, Cotton Seed

Distributors, and the cotton grower associations of

the Central Highlands, Theodore and Biloela

sponsored 12 people involved in the cotton

industry in Central Queensland to visit regions in

the United States of America that had experienced

and managed problematic SLW populations.

Indigenous Law and cultural traditions remain strong and active in many parts of Australia. This project demonstrates a way for local Indigenous groups and other stakeholders to agree on the management of significant places and local issues with the aim of improving cultural and national heritage and Indigenous futures.

The objectives of the LWRRDC scoping review were: 1. To summarise wetland resources in general terms in Australia using existing information, and identify where information required for ecologically sustainable development is lacking. 2. To identify the key issues for wetlands management, within the context of overall natural resources management. 3. To identify and prioritise the generic, national or regional issues for which R&D investment could bring the greatest returns in terms of maximising national benefits. 4. To describe the current state of knowledge of the priority issues in a concise, well referenced format including the scale, impact, significance, costs, threats and opportunities. 5. To propose specific R&D requirements for each issue that will be sufficient to resolve the technical components of the problem. 6. To identify social, economic and policy impediments or constraints to resolving the priority issues and propose R&D or other projects that might assist in overcoming these impediments.

In this issue: Investigating the Salt of the Earth; Digging deep and the quest for super soils; Linking irrigator experience with measured data

This report describes a project undertaken to examine human perception of native vegetation. The project employed photo-questionnaire techniques designed for measuring psychological preferences, adapting these for the purpose of identifying attitudes that promote or hinder the protection of native vegetation. Landholders in south-eastern Australia and urban residents of Melbourne were surveyed to identify preferences for vegetation types.

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.