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The two species of bracken fern, Pteridium esculentumand Pteridium aquilinum, are well known to produce neoplastic lesions and thiamine deficiency when consumed by mammals, with severe consequences to health. New Zealand Pre‐European Māori are known to have consumed rhizomes of P. esculentumas food with little or no recorded consequences to health. Processing methods by Māori prior to consumption may have helped to detoxify this food. We carried out LDH toxicity tests on rhizomes that had been pre‐processed before simulated digestion to test this possibility. We tested rhizomes harvested each month of the year, different components of the rhizome, both raw and roasted rhizomes, rhizomes stored for up to 12 months, and rhizomes leached for up to 24 hours. All specimens remained equally toxic within experimental error. We carried out a detailed analysis of nutrients in bracken rhizome and compared this with kūmara, Ipomoea batatas, another important food plant for pre‐European Māori, and found that bracken rhizome has c. 70% of the caloric value of kūmara. A cost/benefit analysis of the two plants suggested that the reward for effort is greatest for kūmara by a modest amount. Analysis of historic ethnographic observations relating to bracken rhizome from AD 1769 to the 1840s provides complex and contradictory evidence of the role of bracken rhizome in the Māori economic system. Although there is clear evidence that Māori greatly favoured chewing rhizomes, this fondness may result from the presence of one or more plant secondary metabolites (PSM), such as ecdysone, which are known to be addictive. Our analysis of the evidence favours the plant being essentially a famine food, filling in the period between planting and harvest of kūmara, known as the ‘hungry gap’ between October and April in the southern hemisphere. However, it would also have provided an important source of food for travellers, as fern‐lands are widespread. Our analysis of archaeological information did not produce unequivocal direct evidence of bracken rhizome consumption. However, the presence of extreme tooth wear and a unique pattern of first molar dislocation, attributed to the use of teeth to strip starch from rhizomes, has been shown to be present at all periods of New Zealand prehistory. This is contrary to the finding of some other researchers. Les deux espèces de fougères aigles, Pteridium esculentum et Pteridium aquilinum, sont bien connues pour produire des lèsions néoplasies et carence en thiamine lorsqu'elles sont consommées par des mammifères, avec de graves conséquences pour la santé. Nouvelle‐Zélande Maoris Pré‐ Les européens sont connus pour avoir consommé des rhizomes de P. esculentum comme nourriture avec peu ou pas des enregistrements des conséquences sur la santé. Les méthodes de transformation par les Maoris avant la consommation peuvent avoir aidé à détoxifier cet aliment. Nous ont effectué des tests de toxicité de la LDH sur des rhizomes qui avaient été prétraités avant digestion simulée pour tester cette possibilité. Nous avons testé des rhizomes récoltés chaque mois de l'année, différents composants du rhizome, à la fois crus et rhizomes grillés, rhizomes stockés jusqu'à 12 mois et rhizomes lessivés jusqu'à 24 heures. Tous les specimens est resté également toxique dans les limites de l'erreur expérimentale. Nous avons effectué une analyse détaillée des nutriments dans le rhizome de fougère et nous avons comparé cela avec le kumara, Ipomoea batatas, une autre plante alimentaire importante pour les Maoris pré‐européens, et a constaté que rhizome de fougère a c. 70% de la valeur calorique du kumara. Une analyse coûts/bénéfices des deux usines a suggéré que la récompense pour l'effort est la plus grande pour le kumara d'un montant modeste. Analyse des observations ethnographiques historiques relatives à le rhizome de fougère de 1769 à 1840 fournit des preuves complexes et contradictoires du rôle de la fougère rhizome dans le système économique Maori. Bien qu'il soit clairement prouvé que les Maoris favorisaient grandement les rhizomes à mâcher, cette affection peut résulter de la présence d'un ou plusieurs métabolites secondaires végétaux (PSM), comme l'ecdysone, qui sont connus pour être addictifs. Notre analyse des preuves favorise la plante étant essentiellement un aliment de famine, remplissant le période entre la plantation et la récolte de kumara, connue sous le nom de «trou affamé» entre octobre et avril dans le sud hémisphère. Cependant, il aurait également fourni une importante source de nourriture pour les voyageurs, car les fougères sont répandu. Notre analyse des informations archéologiques n'a pas produit de preuves directes sans équivoque de fougères consommation de rhizomes. Cependant, la présence d'une usure dentaire extrême et d'un schéma unique de luxation de la première molaire, attribuée à l'utilisation des dents pour enlever l'amidon des rhizomes, a été démontrée présente à toutes les époques de la Nouvelle‐Zélande préhistoire. Ceci est contraire à la conclusion de certains autres chercheurs.

The aim of this review is to report changes in irrigated cotton water use from research projects and on-farm practice-change programs in Australia, in relation to both plant-based and irrigation engineering disciplines. At least 80% of the Australian cotton-growing area is irrigated using gravity surface-irrigation systems. This review found that, over 23 years, cotton crops utilise 6–7ML/ha of irrigation water, depending on the amount of seasonal rain received. The seasonal evapotranspiration of surface-irrigated crops averaged 729mm over this period. Over the past decade, water-use productivity by Australian cotton growers has improved by 40%. This has been achieved by both yield increases and more efficient water-management systems. The whole-farm irrigation efficiency index improved from 57% to 70%, and the crop water use index is >3kg/mm.ha, high by international standards. Yield increases over the last decade can be attributed to plant-breeding advances, the adoption of genetically modified varieties, and improved crop management. Also, there has been increased use of irrigation scheduling tools and furrow-irrigation system optimisation evaluations. This has reduced in-field deep-drainage losses. The largest loss component of the farm water balance on cotton farms is evaporation from on-farm water storages. Some farmers are changing to alternative systems such as centre pivots and lateral-move machines, and increasing numbers of these alternatives are expected. These systems can achieve considerable labour and water savings, but have significantly higher energy costs associated with water pumping and machine operation. The optimisation of interactions between water, soils, labour, carbon emissions and energy efficiency requires more research and on-farm evaluations. Standardisation of water-use efficiency measures and improved water measurement techniques for surface irrigation are important research outcomes to enable valid irrigation benchmarks to be established and compared. Water-use performance is highly variable between cotton farmers and farming fields and across regions. Therefore, site-specific measurement is important. The range in the presented datasets indicates potential for further improvement in water-use efficiency and productivity on Australian cotton farms.

The article discusses several misconceptions about deep drainage. It looks at whether deep drainage happens during the sealing up during the season behavior of some soils used for irrigation. It also discusses the two types of soil moisture monitoring devices which are those that measure the pressure at which the water is held within the soil and those that measure the water content of the soil.

The article discusses a project on seepage losses initiated by the Darling Downs Cotton Growers Inc. and funded by the Condamine Alliance through Cotton Australia. The Central Downs Irrigators Limited (CDIL) was tasked to probe on how to invest in water use efficiency work that would benefit irrigators in Australia. However, Total Ag Services (TAGS) Dalby and FSA Consulting Toowoomba identified the cause of seepage problems from on-farm storages and showed the cost-benefit of alternative repair methods.

The article reports on the results of a project which assessed the profitability and risk associated with converting a furrow irrigation systems to center pivot and lateral move (CPLM) irrigation systems. Irrigators who are considering such an investment must consider a number of factors. The size of each farm and the cropping system without the CPLM irrigation system and with the CPLM installed was analyzed to determine the annual operating profit. Cash flow of the business was analyzed, including debt repayments, drawings by investors and taxation.

The article presents three case studies which highlighted problems with center pivot and lateral move overhead irrigation machines in Australia. In the first case, several issues were discovered in such machines, including the incorrect placement of the pressure regulators at the top of the dropper instead directly above the sprinkler. It was also found that the center pivot machine had lost end pressure that resulted to more water releases at its head ditch whenever the machine reaches the highest point of a field.

The article details the examination by farmers David and Wayne Lobwein of the efficiency of their furrow irrigation practices. It is said that the examination was prompted by the continued dry conditions. Diviner probes were used by Trev Philp of Landmark to help irrigation scheduling decisions. The Lobweins were enabled by yield mapping of fields to prioritize those fields that most likely to benefit from furrow evaluation.

This paper reviews the factors influencing the nitrogen (N) and phosphorus (P) exports from Australian catchments. Pristine, forested catchments export little N and P and the predominant form of N is dissolved organic nitrogen (DON). As catchments are cleared, exports increase and the predominant form of N changes from DON to dissolved inorganic N (DIN). Soluble reactive P (SRP) represents a roughly constant fraction of total P in these systems. As catchments are cleared, DIN:SRP export ratios increase sharply and DIN comes to represent a larger and larger fraction of the total N. The ratios of total N:P and DIN:SRP in rivers reflect land use and the residence times of the water. In Australian lakes and reservoirs, DON and total Kjeldahl N (TKN)are consumed and DIN is exported downstream. Australian freshwater systems with long residence times show stoichiometric evidence of N limitation, and the frequent occurrence of N-fixing cyanobacterial blooms. Despite TN:TP loading ratios equalling or exceeding Redfield stoichiometry, many Australian estuaries and coastal lagoons also show extensive evidence of rapid denitrification and N limitation. Coastal lagoons also have long water residence times (up to 1 year) and a high proportion of the N load is denitrified.

It is generally accepted by scholars that potatoes were first introduced to New Zealand in the late 18th century by Captain James Cook and the French explorer, Marion du Fresne. Further introductions of potatoes from a variety of sources including possible direct introductions from South America, followed into the 19th century. Maori were quick to recognize the advantages that these new introductions had over their traditional food crops including kumara (sweet potato) Ipomoea batatas and Taro Colocasia esculentum both of which they introduced from east Polynesia some 800-100 years previously. Potatoes soon became a staple item in the Maori diet and an important trade commodity and by the mid-19th century they were growing thousands of hectares of potatoes for that purpose. The various cultivars that were introduced were given Maori names and many of these early types are still grown by Maori, having been passed down through families for many generations. With their deep set eyes, often knobbly irregular shape, "open" leaves and colourful tubers these "Maori Potatoes" are quite distinctive in appearance from modern potatoes and some retain many of the features of Solanum tuberosum subsp. andigena types. This paper discusses the adoption of the potato by Maori, the effects it had on Maori society and the perpetuation of the early cultivars within Maori families and communities. This examination of an introduced crop plant and its intersection with an indigenous people is essentially an ethnobotanical study which in addition to its botanical and anthropological foci includes elements of Matauranga Maori (traditional Maori knowledge) history, geography and horticulture. The preservation of these old potato cultivars by generations of Maori people has made a valuable contribution to conservation of biological diversity.

An editing experiment is presented that selects for a peak on the basis of its chemical shift and that of one of its scalar coupling partners. The selected multiplet is pure in-phase. The editing procedure can be used in conjunction with 1D TOCSY/HOHAHA and NOE measurements. The pulse sequence described is particularly suitable for small molecules; data is presented for Gramicidin S and dehydrotestosterone.

The use of CAD is product. Its use is widespread in the car industry, through most of the process of designing a new most uneven and various at the concept stage when stylists make their contribution. The appearance design of a new vehicle is crucial if it is to be a success in the marketplace. CAD is contributing to reducing lead times and hence to a greater responsiveness to the market. If stylists are to make their contribution effectively they need to be able to maintain the ease and productivity of conventional concept sketching, whilst adding the 3D capability of CAD. Sketch mapping provides the tools and techniques for doing this, and recent refinements to the interface have enhanced its utility.

Measurement of nuclear Overhauser enhancement is one of the mainstays of structural studies of molecules in solution. Measurements, particularly over long distances, are often compromised by spin diffusion. A robust and accurate method for measuring nuclear Overhauser enhancements that are largely free of spin diffusion effects is presented. The effects of using imperfect radiofrequency pulses are considered and experimental data are presented for Amphotericin B.

Measurements of the uptake and loss of 4C in the light and in the dark in the Tasman and Coral Seas have revealed methodological problems with the estimation of productivity in these waters. Rates of productivity estimated without replication, time series incubations and dark controls frequently overestimated the true rates of autotrophic production. The data showed unexpectedly high rates of both uptake and loss in the dark in oligotrophic waters. In oligotrophic oceanic waters, dark incorporation of 14C sometimes equalled the uptake of 14C in the light bottle. Rapid uptake of isotope in the dark controls appeared to be the result of rapid bacterial growth and metabolism. This problem was exacerbated by agitation of the sample before or during the incubation. Tropical samples were particularly susceptible to problems arising from the agitation of the samples. Latitudinal gradients of dark uptake and loss were revealed in these incubations. The loss of label during 8–12 hours in the dark (after 12 hr in the light) was as high as 50% in subtropical waters. The loss was frequently unmeasurable (< 10%) in temperate waters. The time course of 14C uptake indicated active grazing in the bottles and suggested that most of the nighttime losses of label were due to grazing by microheterotrophs. Respiratory losses appeared to be small. Calculated values of the assimilation number (or photosynthetic capacity) which did not correct for dark 14C uptake were too high to be biochemically realistic. The errors were due to the heterotrophic uptake of label and the lack of dark controls. Rapid release of 14C in the dark after incubation in the light meant that the estimate of ‘productivity’ was dependant on the trophic state of the sample and on the period of incubation.

Abstract This paper discusses the relationships between scaling and predictability in ecosystems. The logical basis of ecosystem modelling is explored using ideas first developed in complexity theory and analogies with the behaviour of complex adaptive systems. Any ecological model is a scale-dependent entity and both empirical and dynamic models of freshwater systems have their strengths and weaknesses. The logical basis of modelling using functional groups is explored. I conclude that such an approach can be justified and that such models have predictive power. Any predictive model of freshwater systems must take the major scales of external (atmospheric and catchment) forcing into account as well as the scales of key processes in the ecosystem itself. The importance of so-called ‘pink noise’ spectra, which arise both from external forcing and the internal dynamics of dynamic systems, is noted. The key scales of pattern and process in freshwater ecosystems are discussed in relation to the properties of the major functional groups. In order to have predictive power, I conclude that models of freshwater systems must include sediment exchanges and the properties of aquatic macrophytes as well as water column interactions and the pelagic components. When viewed at the scale of functional groups and the major biogeochemical processes, freshwater ecosystems may not be as complex as is often assumed.

The article deals with a study on the economic benefits and costs of converting furrow irrigation to drip irrigation. The adoption process of drip irrigation systems takes up to three years to achieve potential benefits such as 30 percent water saving and 15 percent yield increase. However, it was also found that investment in converting furrow irrigation to drip generation systems can generate a 20 percent increase in revenue if the irrigation is expanded as a result of water savings. Furthermore, factors like higher water prices, reduced water allocation and the possibility of selling water on the market enhance the benefits of drip irrigation system.

The article discusses the advantage of utilizing automatic weathers station (AWS) to irrigators. It states that AWS offer site-specific atmospheric data that irrigators can use to assist irrigation scheduling decision. It outlines several factors before buying an AWS such as sensor availability, accuracy, robustness, maintenance issues, and technical support availability. INSET: A TA GLANCE....

The article discusses a study in the northern cropping region of eastern Australia that pinpoints key management techniques for high yielding irrigated wheat in both high and low soil-nitrogen fields. Through the selection of varieties that have the highest yield potential and disease resistance, wheat yields of eight tonnes per hectare can reportedly be attained. It is also critical to pinpoint starting soil-N in order to manage water and nitrogen availability during the growing season.

The article focuses on maximizing profits from irrigated cotton. The issue reportedly hinges on both economic and agronomic factors. The economic factors include the relative association between crop price and production cost, while the agronomic factors include the yield response of cotton to irrigation. Economic and agronomic factors are reportedly highly variable with location and season. A simulation of farm gross margin for three scenarios is presented.

The article discusses changes in water productivity in Australia over the past decade. The country has witnessed floods and extended drought during that period, but cotton growers have consistently improved yields and reduced water use. Irrigation Water Use Index (IWUI) has improved from 1.1 bales per megalitre in 2001-2001 to 1.9 bales per megalitre in 2009-2010. Such improvement allegedly represents a huge growth in crop water productivity, and shows the dedication of growers.

The article focuses on the significant improvement in water productivity in irrigated cotton in Australia in 2009. There was a 70% reduction in the volume of irrigation water used by the cotton industry in 2008-2009 compared with the volume in 2000-2001. The upward trend in the Irrigation Water Use Index is partly attributed to continued gain in yields due to genetics and crop management. Water availability has reportedly influenced the profitability of the irrigation sector.

Presents a letter to the editor which compared personal computers against programmable logic controllers.

Analyzes the geology and hydrology in Australia in an aim to examine the possibility of sustainable development in the continent. Impact of the arrival of European settlers on the continent; Status of Australian rivers; Signs of unsustainable land use.

The article explores cotton water related discipline research and development (R&D) done on cotton plants, fields, farms, catchments and communities in Australia. Among the research outcomes are a 40% spike in cotton water productivity over the last 10 years, changed attitudes on issues such as deep drainage, and local catchment groundwater knowledge and products. R&D priorities for 2013 include a focus on plant breeding, agronomy, soil and irrigation management, and monitoring water use.

The article reports on an on-farm storages project of Cotton Catchment Communities CRC which will receive funding from the National Water Commission's Raising National Water Standard Program. It is said to be aimed at measuring and monitoring the evaporation and seepage losses from at least 135 on-farm storages across all valleys in the Australian cotton industry. Also, it will provide information on the extent of losses occurring from storages.

The article focuses on the evaluation of the furrow irrigation practices of farmers David Lobwein and Wayne Lobwein and their families in Darling Downs, Queensland. The continued dry conditions led the farmers and their families to evaluate the efficiency of their furrow irrigation practices. The Irrimate Surface Irrigation Performance assessment equipment was used to evaluate the performance of irrigations in maize on three of their fields.

The article presents information on the Cotton Catchment Communities Cooperative Research Center Water Focus Team in Australia. It consists of 14 research staff from various government bodies and was formed to help cotton and grain irrigators. The team has been working on several projects related to irrigation including the Rural Use Efficiency project.

The paper focuses on WATERpak, the latest in the pak series from the Cotton Cooperative Research Centre (CRC) and Cotton Research & Development Corp. It has been in development from 2002-2004 as a cooperative effort between researchers, consultants, extension staff and growers throughout the Australian cotton industry. The WATERpak manual has been designed to provide technical and practical information to cotton rowers seeking to meet the requirements of the Best Management Practices program. WATERpak aims to empower irrigators to achieve higher levels of productivity and irrigation efficiency. The challenge for irrigators is to find the balance between the costs of improved water use efficiency, environmental stewardship and the maintenance of farm profits. While most irrigated cotton growers are looking to meet the accepted industry standard of one bale of cotton per megalitre, the leading growers are already achieving two bales per megalitre. The use teof WATERpak has been designed around the self assessment checklist for irrigation efficiency at the start of the pak. This season a CRC Water Focus Team member will attend grower meetings in each valley to introduce growers to the use of WATERpak.

Presents a letter to the editor on the reuse of furniture.

This paper reviews the biogeochemistry of carbon, nitrogen, phosphorus and their associated minor elements (iron and sulfur) in rivers, lakes and estuaries. The biogeochemistry of these elements can be explained by the physiology and stoichiometry of the major functional groups of micro- and macro-biota in these ecosystems. Furthermore, the global patterns of nitrogen and phosphorus limitation in freshwater and marine systems are explicable in terms of evolutionary differences between the major functional groups in freshwater and marine ecosystems, and their physiology and stoichiometry, as well as the interactions of carbon, iron, water residence times and ionic strength as the water flows from catchments to the sea. The highly non-linear responses of aquatic ecosystems to changing catchment loads of major and minor elements are explained by the interactions of the major functional groups and by competition between the pelagic and the benthos for nutrients and light.