Most agriculturally important plants, including cotton, are colonised by soilborne fungi known as arbuscular mycorrhizal fungi (AMF). The AMF depend on the plant to supply their energy, in the form of sugars. These fungi colonise the roots internally and develop highly branched structures (arbuscules) inside individual cells of the root. Fungal filaments also grown into the soil surrounding the roots, where they absorb 'immobile' elements such as phosphorus and zinc. The phosphorus and zinc are transported to the roots and transferred to the plant in the arbuscules. Generally, the improved nutrition of the plant outweighs the cost of supplying the fungi with sugars. This type of partnership, is known as arbuscular mycorrhizal symbiosis. In the field, cotton is highly dependent upon AMF for successful growth and always forms arbuscular mycorrhizas (Nehl et al 1994).

While the importance of biodiversity in ecosystem function has been accepted for some time (Tilman & Downing 1994), only recently has the relative importance of the diversity of functional characteristics of the biota been recognised (Grime 1997). Studies of above ground diversity predominate in the literature (Loreau et a1 2001). Little is known of diversity in soil. Soil is more complex and biologically diverse than above ground ecosystems (Wardle & Giller 1997). Thus it might be argued that the loss of a small number of taxonomic groups from a complex substrate such as soil will have little impact because many different microbes would contribute to the functions of soil and therefore, many species would be functionally redundant. However, research has found that high biodiversity may be considerably more important in complex ecosystems, such as soil, than in simple systems (Grime 1997) especially when changes over time and space affect the system (Loreau et al. 2001). Soil is the location for mineral cycling, decomposition of organic materials, and flow of energy. Understanding the processes regulating these functions, and their affect on plant growth, justifies understanding the biological diversity housed in soil

Final Report

Final Report of action grant

Final Reports National invertebrate pest initiative

The problem of water scarcity has become one of the most controversial topics in Australia over the past decades, with particular focus being the 'sustainable' allocation of water between extractive and environmental purposes. Geographical factors are defining the extreme variability in climate and water supply in Australia and, in the past, this was used as a rationale for the construction of large irrigation projects to deliver water to rural, urban, and industrial users. During this 'expansionary' phase of Australia's water use sector, the cost of augmenting supply was relatively low and environmentalconsiderations were secondary to the development imperative. As a result, water resources became over-allocated for extractive uses spurred on by consistent underpricing of water, which indicated a failure to reflect the true cost of water supply. As Australia's water economy entered a 'mature' phase, it was no longer possible to increase supply cheaply as the most easily accessible water resources had already been captured. This was followed by widespread environmental degradation manifested in the Murray- Darling Basin, the nation's largest river basin which hosts much of Australia'sagricultural production. Consequently, the focus shifted towards demand management, leading to a myriad of regulation aimed at increasing the allocative efficiency of scarce water resources. Towards this end, substantial government funding was injected into the various initiatives throughout the water reform process.Despite the on-going government activities in the area of water reform, the understanding of the actual economic impact and environmental outcomes of various water policies in practice remains limited. In the absence of such understanding, the effectiveness of various government water initiatives is ambiguous and inevitably compromised.The present study addresses this knowledge gap by establishing a method for evaluating the economic and environmental outcomes of environmentally-oriented polices that affect irrigated industries in a catchment. The method is based on an integrated biophysical and economic modelling approach, which enables spatial relationships to be captured accurately allowing a more realistic analysis. Information generated from a computer based biophysical simulation model form the basis of an economic optimisation model with constraints pertaining to environmental targets and water supply limits. The economic model consists of a linear programming and dynamic programming component, and involves the optimisation of resource use from a catchment manager's perspective, seeking to achieve efficient resource use but at the same time conform to given environmental objectives. This two-stage modelling process was required to determine the optimal intra-seasonal and inter-seasonal water allocation, given various catchment environmental targets. The interdisciplinary approach enables the economic and ecological outcomes of the catchment management policies to be simulated and assessed at a spatially explicit scale, due to the link to Geographical Information Systems (GIS) in the biophysical model.

The Technology Transfer Project has had the responsibility of providing a public face for the Cotton Catchment Communities CRC. It promoted the cotton, NRM and community research industry and the wider public. This was successfully achieved mainly through the development and maintenance of the Cotton Catchment Communities web site. The project also assisted with the production of materials for hardcopy and distribution of same using contact lists maintained by this project.The site is the main repository of research and extension material produced by Cotton CRC and CRDC projects. The project aimed to keep the web site up to date and available to industry (via various means such as what's new pages, RSS feeds, up to date site mapping and promotion via electronic newsletters and paper publications and recently Twitter feeds). This was in order to promote visitation and consequent exposure to the latest research and extension material.Where possible the opportunity was made to enhance paper base publications or present them in a web friendly fashion with enhanced utility over paper based documentation. The Weed ID guide (on the web the Weed ID tool) from WEEDpak Section A3 Charles. G et al) is a good example.The project coordinated with the national cotton extension team and Cotton Development and Delivery teams to assist industry wide extension campaigns to assist local extension officers.The project also provided web services to researchers for conducting surveys and also provided services to the Cotton CRC for the running of conference -registration, web sites contacts, resource creation (booklets and MP3 CD's).

Soil organic carbon (SOC) is an indicator of soil health, as it exercises vital roles as a nutrient source as well as a contributor to a favourable soil structural conditions. It is well documented that cultivation and cropping of soil under native vegetation may lead to reduction in SOC. Estimates of 54% and 60% loss of SOC from initial levels have been reported for cotton and cereal based farming systems in the cropping region of north-western NSW. These estimations are useful in terms of gauging SOC levels under past management practices. However, of greater interest is the need to know how and at what rate SOC had changed over time as well predicting these changes into the future under existing and improved management practices. The Rothamsted Carbon Model (RothC) is a tool that facilitates the estimation of SOC changes in the past and their prediction into the future.In his study, we used soil profile data from the Australian Cotton Soil Database (ACSD) (Odeh et al. 2004) as inputs for a modified version of the RothC model to simulate SOC changes under existing management practices in a 3000km2 study area, west of Narrabri, NSW. Based on actual measurements performed in 1996, modelled estimates of SOC were considered reseanable. Estimates for 'continuous cotton' systems performed best (RMSE=0.19%), followed by 'cotton-legume rotation', 'cotton-grain rotation', 'native vegetation' and 'continuous grain' systems (RMSE= 0.24, 0.31, 0.35, 0.40% respectively). We then used the model outputs to interpolate onto a dense grid of the study area, the change in SOC from initial levels to 2003, using various ancillary data. We concluded that, in areas of irrigated cotton, there has been between 45-53% reduction in SOC from initial levels. To improve upon the models predictive ability, adjustments to some model inputs, verification of initial levels of SOC, determination of land clearing events and a harmonious land use classification, compatible to the ACSD are some means in which to do so. Overall, the base methodology developed during this exercise could be extended to other areas detailed by the ACSD. Value adding to this data through estimation of SOC fluxes under modified management systems and future climate scenarios are likely possibilities in future studies.

This research has shown that community beliefs about the future role of cotton in traditional 'cotton communities varies considerably. This will certainly have implications for the cotton industry in realising its vision for the next 20 years, particularly in the contexts of remaining resilient to future challenges, and as a respected part of the communities where the industry operates. Undoubtedly, cotton will remain part of the economic future of these communities, but the drivers and associated consequences identified here will influence the relative contribution cotton makes to the lives and lifestyles of the members of these 'cotton communities'.Perhaps the most telling finding of this research has been the recognition that regional economic diversification can help regional 'cotton communities' to become more resilient - that is, to better weather the environmental, demographic and economic variability and uncertainty that is a constant companion of the Australian farmer. Importantly, farming and non-farming members of cotton communities may have different perceptions of the need for economic diversification (though the distinction is a complex one that can only be partially understood with the minimal data obtained in this research). Cotton farmers have historically adapted to environmental variability and water uncertainty by adopting a flexible farming approach - growing crops as a response to water availability and market price. Members of cotton communities (who aren't directly involved with the cotton industry) have traditionally relied on the economic success of the farmers in their communities as the primary source of local economic contribution, but suffer in poor times. The physical detachment of the non-farming cotton community from the land (the opposite of which often encourages the cotton grower to continue in difficult times) means they are more open to new opportunities that economic diversification prospects like mining and tourism might offer.Importantly, the consequences of environmental, demographic and economic drivers on the cotton community are all closely connected, with the reliance on local agriculture playing a key role in the 'life' and functioning of those cotton communities included in this research project. For example, agricultural efficiency in cotton mechanisation (and also falling water allocations and drought), have reduced the labour intensity of cotton growing in Australia. This in turn reduces the population base of cotton communities, and subsequently the quality of central services (like health and education) that are provided in these places. These changes further reduce the attractiveness of regional areas, and the likelihood that people choose to settle in these locations.Even so, community members who took part in this research generally had strongly positive attitudes to the future of their communities, and felt that cotton would play a central role in the future. This highlights the fact that most rural and regional areas in Australia continue to be dependent on agriculture, which contributes to the social and economic vitality of these communities. As such, visions of the future of the community, particularly of those communities where cotton, and agriculture in general, predominate will closely revolve around the contributions of agriculture and farming people to those communities into the future.

Aquaculture is the fastest growing food-producing industry in the world, and currently contributes nearly 50% of total fisheries production. It has great potential in Australia because of our limited wild fisheries, over-exploitation of some fisheries, and importation of large quantities of fish. Freshwater fish contribute around half the global aquacultural production. The native freshwater fish silver perch (Bidyanus bidyanus) has significant potential, and R&D by the NSW Government has provided a technical basis for industry development. Although around 500 tonnes are produced annually in ponds, the industry has not realised its potential to date due to difficulties with pond management, slow growth and losses to bird predation and infectious diseases during winter, the high cost of feeding and the small scale of most farms. Cages are easy to manage, facilitate efficient feeding, and protect fish from birds. Cages also enable the use of water bodies such as storages on cotton farms that are otherwise unsuitable for commercial aquaculture. Water for irrigation is a substantial and recurring cost to cotton farmers, and freshwater aquaculture may offer an opportunity to add value to the water and improve water-use efficiencies. This study demonstrated that silver perch is an excellent species for cage culture. High survival and good growth at high stocking densities lead to high production rates. Optimal stocking densities based on fish performance and welfare were identified for different production phases (e.g.100 fish/m3 for grow-out to > 500 g). Commercially-available diets with 30-45% protein and 10-17 MJ/kg energy were suitable, and the cost-effectiveness of feeding was determined principally by purchase price. A new strategy of over-wintering fingerlings at elevated temperatures in a tank-based recirculating aquaculture system (RAS) significantly improved survival and growth, and shortened the overall culture period.