http://hdl.handle.net/2123/116 Search the Channel search http://ses.library.usyd.edu.au/simple-search http://hdl.handle.net/2123/192 Title: Study Of Water Use And Environmental Aspects Of Rice Growing<br/><br/>Authors: Caldwell, Bruce<br/><br/>Abstract: The Council of Australian Governments (COAG) has agreed to a nationwideapproach to water reform. The outcomes of the reform process are already havingan impact on irrigation and ricegrowing and further impacts can be expected. Suchchanges should affect the direction of some of the future research to be undertakenby the Co-operative Research Centre for Sustainable Rice Production.The long-term sustainability of irrigation systems in arid zones has been shown,world wide, to have technical difficulties. As ricegrowing in arid zones is absolutelydependent on irrigation it is obvious the eventual sustainability of rice is inextricablylinked to the sustainability of the irrigation systems as a whole.If irrigation systems start to fail for whatever reason (e.g. environmental degradation,water allocated to other purposes) then ricegrowing will decline.It is recognised that ricegrowing, as an irrigation activity, contributes to theenvironmental problems associated with irrigation. It is thus of fundamentalimportance to have a full understanding of this aspect of ricegrowing. It is alsoimportant that current rice farming practices and research efforts are adequatelyaddressing such issues.This study examines the extent of ricegrowing as the predominant irrigation activity inthe Murrumbidgee and Murray Valleys of New South Wales. Past and currentpolicies of governments are reviewed in relation to access to water for irrigation andits use for ricegrowing. Data has been compiled on rice production, water availability,water use, ground watertables and salinity as these relate to the rice industry. http://hdl.handle.net/2123/191 Title: Analysing the Benefits of Growing Crops after Rice in the Rice Growing Areas in Australia<br/><br/>Authors: Faour, Khaled; Singh, Rajinder; Humphreys, E; Smith, David; Mullen, John<br/><br/>Abstract: The Murrumbidgee Irrigation Area (MIA), the Coleambally Irrigation Area (CIA), and theMurray Valley (MV) constitute the major Australian rice growing areas and are located insouthern east Australia. According to the Ricegrowers' Association of Australia Inc. (2002),the annual value of production of rice was $357 million in 2001 and the industry generatesmore than $500 million from value-added exports annually, allowing these rice growing areasto play a significant role in the Australian economy.The rice growing areas are also among the areas where the sustainability of irrigatedagriculture is under threat from rising watertables, soil salinity and other environmentalconsequences. The depth to watertables in more than 70 per cent of the MIA (MIAL&WMP, 1998), around 35 per cent of the CIA (CICL, 2001), and around 60 per cent of theMV (Murray Irrigation, 2001) is now around two metres from the soil surface. With thecurrent land use practices, around 20 to 30 per cent of regions such as the MIA couldbecome moderately salinised in the next 30 years due to rising watertables (Humphreys et al.,2001). Water leaching and run-off from rice-based farms form further problems.Paddocks are flood-irrigated during rice growing period between November to March.Although irrigation water is released prior to rice harvest, much of the water is retained bythe soil even after rice harvest. The soil then slowly drains this water along with the addedwinter rainwater into the watertable beyond the root zone. This wet soil profile has thepotential to become an extra economic resource for rice-based farms whenever it can be usedto grow another crop during winter straight after rice.Growing winter crops immediately after rice harvest may reduce the amount of waterdrainage into watertables on rice-based farms. Successful adoption of this potentiallyattractive option seems to depend on good weather and rootzone water conditions, gooddrainage and timeliness in the rice harvesting, stubble burning, and winter crop sowingoperations. Among the constraints for adding crops after rice are too much rain orwaterlogging for the winter crop to survive, problems with stubble burn, pests, weeds, andunsuitable machinery leading to a high risk of crop failure (Humphreys and Bhuiyan, 2001).As one of the strategies to overcome the problems of rising watertables in rice growing areas,the Rice CRC is conducting Project 1205 “Quantifying and Maximising the Benefits of Cropsafter Rice”, henceforward referred to as Project 1205. Project 1205 aims at determining theconstraints and the success factors for rice growers to produce winter crops and pasturesafter rice, and at measuring the impacts of this practice on environmental and economicsustainability. In particular, the project aims to measure the effects of growing wheat afterrice on the productivity and water use efficiency of the rice-wheat cropping system.2The objectives of this economic analysis of project 1205 are:· To identify the common crop rotations in the main Australian rice-based farming systems,both with and without crops after rice;· To estimate the potential financial benefits of growing crops after rice;· To identify the economic benefits to the community from reduced accessions togroundwater; and· To compare returns with the costs to the CRC and its partners of developing andextending this technology.To measure the likely financial and economic benefits of growing crops after rice, the studyrelied heavily on the results from Humphreys et al. (2001). http://hdl.handle.net/2123/190 Title: Valuing a Test for Nitrogen Status in Rice<br/><br/>Authors: Singh, Rajinder; Williams, Robert; Mullen, John; Faour, Khaled<br/><br/>Abstract: Nitrogen is a crucial input for the efficient production of rice and is generally applied in twosplit treatments. The first treatment is given before flooding the rice paddocks at sowing timeie at the pre-flooding (PF) stage. The second treatment is applied within a week after thebeginning of the panicle initiation (PI) stage. There is no pre-sowing test to estimate nitrogenrequirements and farmers use cropping history to make this decision. Later in the seasonfurther nitrogen can be applied on the basis of existing Near Infra-red Reflectance (NIR) basednitrogen tissue test but yield potential has often been established by this time. A further sourceof yield risk is temperature prior to flowering and at high rates of nitrogen there is a potentialfor yield losses at low temperatures.The aim of one of the projects, funded by the Cooperative Research Centre (CRC) forSustainable Rice Production, is to develop a nitrogen test for soils of rice paddocks. Thiswould help determine the amount of nitrogen available in the soil and how much more nitrogenneeds to be applied at the PF stage.The aim of this study is to first value the information that is provided to the rice growers at PFby the soil test on nitrogen availability and then measure returns to investment on research andextension to develop and promote this test. The problem is first presented in a decision treeframework. The Bayesian framework is then applied, where information provided by the test isused to revise perceived probabilities of yield outcomes under different nitrogen regimes.MaNage rice, a bio-economic model, is used to work out payoffs from different rates ofnitrogen at PF on different nitrogen status soils. Finally, returns to investment on R&D aremeasured within a benefit-cost framework.The results reveal that the information provided by the soil test is valuable as the test helpsfarmers to use nitrogen more profitably. The outcome of the benefit-cost analysis shows thatwith the current accuracy levels the benefits from the new test are not sufficient to meet thecosts involved on research. If the scientists were able to improve the accuracy of the test (ie atpar with existing NIR tissue test), the returns to investment on the project would be quitesignificant. http://hdl.handle.net/2123/189 Title: Economic Analysis of Improving Cold Tolerance in Rice in Australia<br/><br/>Authors: Singh, Rajinder; Brennan, John P; Farrell, Tim; Williams, Robert; Lewin, Laurie; Mullen, John<br/><br/>Abstract: The occurrence of low night temperatures during reproductive development is one of thefactors most limiting rice yields in southern Australia. Yield losses due to cold temperatureare the result of incomplete pollen formation and subsequent floret sterility. Researchers havefound that in 75% of years, rice farmers suffer losses between 0.5 and 2.5 t/ha. Research isbeing undertaken to identify overseas rice varieties, that are cold tolerant under the localweather conditions and by using those genotypes as parent material, develop cold tolerancevarieties of rice. A yield simulation model was used to measure reduction in losses due tocold at different minimum threshold temperatures, while the SAMBOY Rice model was usedto measure the costs and returns of a breeding program for cold tolerance. The results of theeconomic analysis reveal that new cold tolerant varieties would lead to significant increase infinancial benefits through reduction in losses due to cold, and an increase in yield from thebetter use on nitrogen by the cold tolerant varieties. The returns to investment on the researchproject are estimated to be high.