Making nutrition decisions in high-cost environments

Take home messages • At average fertiliser costs, return on investment to nitrogen applications exceed 5:1, i.e. every dollar spent on nitrogen results in $5 of additional profit • When N prices double, growers are still receiving$2.10 in profit for every dollar spent on nitrogen, and at triple the cost nitrogen is still expected to return $0.85 in additional profit for every dollar spent • With higher N prices profitable N responses to winter cereals are only expected under favourable grain prices or seasonal conditions • Soil testing and precision/variable nutrient application become more valuable as nutrition costs rise

Nitrogen cycling and management decision making in Central Queensland farming systems – N availability and recovery across the farming system – N impacts on productivity – implications for management in CQ

Take home messages The nitrogen (N) fertiliser demand for cereal cropping systems can increase due to two factors: 1. A reduction in the amount of soil organic N mineralised due to the continued decline of natural capital (soil organic carbon and total nitrogen) that occurs under cropping; and 2. An increased crop N demand due to higher yield potentials resulting from optimising other components of the cropping system. The amount of biological N fixation by pulse crops (chickpea/mungbean) is related to the crop yield and biomass and the availability of soil mineral N from mineralisation or carry-over of residual fertiliser. Where deep phosphorus (P) and potassium (K) application increases chickpea biomass (and grain yield), there is generally more N fixed. While some of this is re-exported in grain, the greater residue return means more N is carried forward to the next crop. Growers have a selection of fertiliser N management practices that have differing strengths and weaknesses – it is not a one-size-fits-all model for CQ (or northern region) farming systems. The 4R framework allows choice of rate, source, time and place for any nutrient applied to be implemented suiting each growers’ preferences, with on-going research addressing several themes in regional Qld

Diversity, Trends, Opportunities and Challenges in Australian Grasslands–Meeting the Sustainability and Productivity Imperatives of the Future?

Grassland production systems contribute 40% to Australia’s gross agricultural production value and utilise over 50% of its land area. Across this area a broad diversity of systems exist, but these can be broadly classified into four main production systems: 1. Pastoral grazing of mainly cattle at low intensity (i.e. \u3c 0.4 DSE/ha) on relatively unimproved native rangelands in the arid and semi-arid regions of northern and central Australia; 2. Crop-livestock systems in the semi-arid zone where livestock graze a mixture of pastures and crops which are often integrated; 3. High rainfall permanent pasture zone in the coastal hinterland and highlands and; 4. Dairy systems covering a broad range of environments and production intensities. A notable trend across these systems has been the replacement of wool sheep with beef cattle or meat sheep breeds, which has been driven by low wool prices. Although there is evidence that most of these systems have lifted production efficiencies over the past 30 years, total factor productivity growth has failed to match the decline in terms of trade. This has renewed attention on how research and development can help increase productivity. In addition, these industries are facing increasing scrutiny to improve their environmental performance and develop sustainable production practices. We propose several areas in which grasslands research and development might help provide gains in system productivity and sustainability. In particular, pasture productivity might be improved by filling gaps in the array of pastures available either through exploring new species or improving the adaptation and agronomic characteristics of species currently sown. Meanwhile there is a need to maintain efforts to overcome persistent and emerging constraints to pasture productivity. Improving livestock forage feed systems and more precise and lower cost management of grasslands would translate into improved utilisation and conversion of forage produced into livestock products. There is significant scope to capture value from the ecological services grasslands provide and mitigate greenhouse gas emissions from livestock production. Multi-purpose grasslands provide not only grazing for livestock but produce other food products such as grain which may also have potential to integrate livestock with cropping. However, reduced human research capacity in pasture science will challenge our ability to realise these potential opportunities unless efforts are made to attract and support a new generation of pasture scientists

Evaluation of Crop Production and Water Use Efficiency of Autumn-Sown Annual Forage Crops on the Rainfed Region of Loess Plateau China

The Loess Plateau is one of the most important rainfed regions in China, but rainfall is the most significant factor limiting crop production. In this region rainfall from July to September accounts for 56% of the annual total, providing enough water resources for the growth of autumn-sown crops. Although increasing forage production with autumn sown crops is considered an important means of balancing crop forage and livestock management, suitable species with high yields and good water use efficiency (WUE) are not well defined. The relationship between yield and water use efficiency has been shown to vary with plant species and harvest time (Siahpoosh et al. 2011), indicating that good water management can increase yields. It is therefore necessary to establish efficient water management strategies to increase the yield of autumn-sown crops. The objective of this study was to evaluate annual production of forage crops under autumn sowing conditions and identify their optimal WUE, based on crop production and evapo-transpiration (ET)

Relation of Residue Biomass after Defoliation to Regrowth Dry Matter, WSC and Grain Yield of Winter Wheat

The importance of defoliation height on final yield in dual-purpose wheat is inconsistent. In one study no difference in final wheat yield following a severe grazing at 2 cm compared to light grazing at 6 cm was found (Dann et al. 1983). In contrast, clipping at 3 cm above ground level significantly reduced grain yield compared to 7 cm (Arzadun et al. 2006). An explanation for these inconsistent results may be an underestimation of the value of the remaining biomass and its role in the regrowth process (Fulkerson and Donaghy 2001). In this study, the percentage of residue biomass remaining after defoliation was considered when examining the effect of defoliation height on dry matter accumulation and water-soluble carbohydrate (WSC) during wheat regrowth on the Loess plateau, China

Nitrogen and water dynamics in farming systems – multi-year impact of crop sequences

Take home messages • Grain legumes have utilised soil mineral nitrogen (N) to the same extent as cereal crops and have higher N export which often offsets N fixation inputs • Additional applied N reduced the depletion of background soil mineral N status at most sites; we are recovering a high percentage (>50%) in soil mineral pool. • Application of ~50 t/ha of compost or manure (10 t/ha OC) coupled with N fertiliser rates for 90th percentile yield potential has dramatically increased the soil mineral N in four years • Decreasing cropping frequency has reduced N export and so stored more N over the longer fallows, which has reduced N fertiliser requirements for following crops • Long fallows are mineralising N and moving N down the soil profile even under some very dry conditions • Most excess N is not lost in the system rather it is moved down the soil profile for future crops • The marginal WUE of crops (i.e. the grain yield increase per extra mm of available water) is lower when crops have less than 100 mm prior to planting. Hence, waiting until soil moisture reaches these levels is critical to maximise conversion of accumulated soil moisture into grain • The previous crop influences the efficiency of fallow water accumulation with winter cereals > sorghum > pulses. Long fallows are also less efficient than shorter fallows (<8 months). This has implications for assuming how much soil moisture may have accumulated during fallows

End stage renal disease and survival in people with diabetes:a national database linkage study

© The Author 2014. Published by Oxford University Press on behalf of the Association of Physicians. Funding This work was supported by the Wellcome Trust through the Scottish Health Informatics Programme (SHIP). The SHIP is collaboration between the Universities of Aberdeen, Dundee, Edinburgh, Glasgow and St Andrews and the Information Services Division of National Health Service National Service Scotland. Funding for diabetes register linkage and data extraction was provided by the Chief Scientist’s Office of the Scottish Government. The Scottish Diabetes Research Network receives financial support from National Health Services Research Scotland. The Scottish Renal Registry is funded by the Information Services Division of National Health Service National Services Scotland but relies heavily on the goodwill of the contributing renal units who spent a large amount time working with Scottish Renal Registry staff to ensure that the data held within the register are accurate and complete.Peer reviewedPublisher PD