Durum wheat : a potential new crop for Western Australia

The export orientation of our grains industries and the current favourable position of durum wheat in the world trade make this an opportune time to examine the propsects for durum wheat in Western Australia. Alfredo Impiglia and Wal Anderson summarise the known requirements for consistant production of high quality durum that will lead to the establshment of a new industry in Western Australia

Production of high-value wheats : one sustainable answer to the cost:price squeeze

Farmers and scientists alike over the past decade have sought to address the declining terms of farm trade (the cost.price squeeze) by increasing wheat yields in ways that will ensure both their economic and ecological survival. Nevertheless, costs have continued to increase as a proportion of the value of the product. Many farmers have increased their wheat yields substantially and the industry as a whole is more conscious of the quality of its product. Over the past 10 years or more there has been intense interest in, and considerable adoption of. conservation farming techniques such as minimum tillage, residue retention, cultivation on the contour, diverse rotations and tree planting. Yet in many places salinity has increased, soil erosion has continued, herbicide resistant grasses have appeared and soil fertility has possibly declined

Early sowing : one key to improved yields of cereal crops

Early sowing of cereal crops is one of the most important management practices through which Western Australian cereal growers can increase yields. Researchers have long known that in theory early sowing should mean improved growth and water use efficiency - which both contribuite to increased yields. Application of this knowledge has had to await new tillage and herbicide technology, but recent research in the northan and central wheatbelt has now demonstrated the advantages of early sowing in practice. And more exciting yet, there is evidence that yield responses to weed control and applied fertilizers may also be greater in early sown crops. Nothing comes without some cost, and there are also specific risks associated with early sowing of crops. Management may have to change to allow for these risks, but the benefits may be substantial

Where to settle in a rapidly expanding bird colony : A case study on colony expansion in High Arctic breeding geese

Acknowledgments Juliet Blum, Malcolm Parsons and Troels Hastrup are thanked for their contributions to data collection in the field. We are indebted to Christiaane Hübner for her considerable help before, during and after fieldwork. The Norwegian Polar Institute supplied the vital logistic support and the Governor of Svalbard allowed access to Sassendalen.Peer reviewedPublisher PD

High-Arctic nesting geese occupying less favourable nest sites are more vulnerable to predation

We thank Norwegian Polar Institute for logistical sup-port and the Governor of Svalbard for allowing access to Sassendalen. The authors thank the Climate-ecological Observatory for Arctic Tundra programme for assistance with this study. Comments and suggestions from review-ers greatly improved the manuscript, and we thank them for their time and recommendations.Peer reviewedPublisher PD

Disturbance, recovery and tundra vegetation change : Final report project 17/92 - to Svalbard Environmental Protection Fund

Preprin

Laser-noise-induced correlations and anti-correlations in Electromagnetically Induced Transparency

High degrees of intensity correlation between two independent lasers were observed after propagation through a rubidium vapor cell in which they generate Electromagnetically Induced Transparency (EIT). As the optical field intensities are increased, the correlation changes sign (becoming anti-correlation). The experiment was performed in a room temperature rubidium cell, using two diode lasers tuned to the $^{85}$Rb $D_2$ line ($\lambda = 780$nm). The cross-correlation spectral function for the pump and probe fields is numerically obtained by modeling the temporal dynamics of both field phases as diffusing processes. We explored the dependence of the atomic response on the atom-field Rabi frequencies, optical detuning and Doppler width. The results show that resonant phase-noise to amplitude-noise conversion is at the origin of the observed signal and the change in sign for the correlation coefficient can be explained as a consequence of the competition between EIT and Raman resonance processes.Comment: Accepted for publication in EPJ

Biding time before breeding: flexible use of the Arctic landscape by migratory geese during spring

We thank the Governor of Svalbard for allowing access to study sites and the University Centre in Svalbard and Norwegian Polar Institute for logistical support.Peer reviewedPublisher PD

Crops in the woolbelt : current options and emerging prospects

It has traditionally been more profitable to grow sheep for wool in the medium rainfall parts of the south-west of Western Australia than to grow crops . Crop production has been difficult owing to the hilly terrain, the frequency of waterlogging, the high incidence of damaging frosts in some areas, the frequency of losses from diseases, difficulties with wet weather at harvest, and a lack of adapted crop varieties. Advances over the past decade have made cropping on a limited scale potentially profitable in the woo/belt. This article is intended to bring the various options for crop production to the attention of wool growers. Further detailed information will be required for successful production and is available from your local office of the Department of Agriculture

Short-term variability in Greenland Ice Sheet motion forced by time-varying meltwater inputs: implications for the relationship between subglacial drainage system behavior and ice velocity.

High resolution measurements of ice motion along a -120 km transect in a land-terminating section of the GrIS reveal short-term velocity variations (<1 day), which are forced by rapid variations in meltwater input to the subglacial drainage system from the ice sheet surface. The seasonal changes in ice velocity at low elevations (<1000 m) are dominated by events lasting from 1 day to 1 week, although daily cycles are largely absent at higher elevations, reflecting different patterns of meltwater input. Using a simple model of subglacial conduit behavior we show that the seasonal record of ice velocity can be understood in terms of a time-varying water input to a channelized subglacial drainage system. Our investigation substantiates arguments that variability in the duration and rate, rather than absolute volume, of meltwater delivery to the subglacial drainage system are important controls on seasonal patterns of subglacial water pressure, and therefore ice velocity. We suggest that interpretations of hydro-dynamic behavior in land-terminating sections of the GrIS margin which rely on steady state drainage theories are unsuitable for making predictions about the effect of increased summer ablation on future rates of ice motion. © 2012. American Geophysical Union