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Nitrogen (N) management is critical to the profitability of grain production systems, however careful management of fertiliser is needed to minimise environmental impacts. We investigated the effect of five N fertilisation strategies on nitrous oxide (N 2 O) emissions and nitrogen use efficiency (NUE) of rainfed wheat grown on a clay soil in a temperate, semi-arid environment of south eastern Australia during 2013 and 2014. Treatments included urea application (50 kg N/ha) at sowing with and without nitrification inhibitor (3,4–dimethylpyrazole phosphate) and surface broadcasting of urea with and without urease inhibitor (n-butyl thiophosphoric triamide) at the end of tillering plus an unfertilised control. Daily N 2 O emissions were low and responsive to in-season rainfall and fertiliser addition at sowing. Cumulative emissions from sowing until harvest were highest where N was applied at sowing in 2013; 160 g N 2 O-N/ha, while the 0 N control emitted 28 g N 2 O-N/ha (over 201 days). Emissions during 2014 were 77% lower than 2013 due to dry seasonal conditions; cumulative emissions were 49 g N 2 O-N/ha where N was applied at sowing, with background emissions of around 0 g N 2 O-N/ha (over 177 days). Inhibitors showed limited scope for reducing N 2 O emissions in this environment, however deferring N application until the end of tillering reduced N 2 O emissions. Grain yield responses to fertiliser were significant; increasing grain yield by 11–31% and NUE was generally high (recovery efficiency > 68%). However, deferring N application until the end of tillering in 2014 reduced yield (− 19%) and recovery of applied N (− 74%).

OBJECTIVE: To decrease unnecessary antibiotic use for acute respiratory tract infections in adults in a point‐of‐service health care setting. DESIGN: Prospective, nonrandomized controlled trial. SETTING: An urban urgent care clinic associated with the major indigent care hospital in Denver, Colorado between October 2000 and April 2001. PATIENTS/PARTICIPANTS: Adults diagnosed with acute respiratory tract infections (bronchitis, sinusitis, pharyngitis, and nonspecific upper respiratory infection). A total of 554 adults were included in the baseline period (October to December 2000) and 964 adults were included in the study period (January to April 2001). INTERVENTIONS: A provider educational session on recommendations for appropriate antibiotic use recently published by the Centers for Disease Control and Prevention, and placement of examination room posters were performed during the last week of December 2000. Study period patients who completed a brief, interactive computerized education (ICE) module were classified as being exposed to the full intervention, whereas study period patients who did not complete the ICE module were classified as being exposed to the limited intervention. MEASUREMENTS AND MAIN RESULTS: The proportion of patients diagnosed with acute bronchitis who received antibiotics decreased from 58% during the baseline period to 30% and 24% among patients exposed to the limited and full intervention, respectively (P < .001 for intervention groups vs baseline). Antibiotic prescriptions for nonspecific upper respiratory tract infections decreased from 14% to 3% and 1% in the limited‐ and full‐intervention groups, respectively (P < .001 for intervention groups vs baseline). CONCLUSION: Antibiotic use for adults diagnosed with acute respiratory tract infections can be reduced in a point‐of‐service health care setting using a combination of patient and provider educational interventions.

Improving nitrogen (N) fertiliser uptake of crops growing in soils susceptible to waterlogging could potentially reduce fertiliser input costs and harmful losses of N to the surrounding environment. The fate of 15 N labelled urea applied to wheat cv. Bolac was studied on brown chromosol soils at Hamilton and Tarrington, in the high rainfall zone of south western Victoria, in south eastern Australia. Wheat was fertilised with 15 N-urea solution, either deep banded 0.1 m below the seed at sowing or top-dressed with or without the nitrification inhibitor DMPP (3,4- dimethylpyrazole phosphate or ENTEC ® ) later in the crops development. Daily temporal topsoil (0–0.1 m) water was monitored, throughout the growing season, and at physiological maturity the recovery of 15 N-urea in straw, grain and soil (to 0.4 or 0.6 m depth) was measured. Delaying untreated 15 N-urea application until top-dressing at mid-tillering to first node stage of growth resulted in significantly ( P  < 0.001) greater recovery of applied N than when deep banded at sowing or top-dressed shortly after crop emergence. However, top-dressing with DMPP did not significantly improve crop recovery of 15 N-urea compared with untreated urea, except when top-dressed early in the growing season. Across all sites, between 64 and 84 % of the applied 15 N-urea was recovered in the plant and soil at maturity when top-dressed at mid tillering to first node, compared with 7–42 % when 15 N-urea was either deep banded at sowing or top-dressed shortly after crop emergence. The poor recovery of 15 N-urea when applied around sowing appeared to result from wet to waterlogged soil and subsequent gaseous or drainage losses before wheat reached peak growth and demand for N in spring. Despite, the poor recovery from 15 N-urea applied early in the growing season, wheat grain yields were the same as those top-dressed with 15 N-urea; the former treatment compensating for low fertiliser recovery by sourcing more N from the soil. All sites had high concentrations of topsoil organic C (>2.8 %) and the potential for large rates of mineralisation during the growing season.

Nitrous oxide (N 2 O) is a potent greenhouse gas released from high rainfall cropping soils, but the role of management in its abatement remains unclear in these environments. To quantify the relative influence of management, nitrogen (N) fertiliser and soil nitrification inhibitor was applied to separate but paired raised bed and conventionally flat field experiments in south west Victoria, to measure emissions and income from wheat and canola planted 2 and 3 years after conversion from a long-term pasture. Management included four different rates of N fertiliser, top-dressed with and without the nitrification inhibitor Dicyandiamide (DCD), which was applied in solution to the soil in the second year of experimentation. Crop biomass, grain yield, soil mineral N, soil temperature and soil water and N 2 O flux were measured. Static chamber methodology was used to identify relative differences in N 2 O loss between management. In the second crop (wheat) following conversion, N 2 O losses were up to 72 % lower ( P  < 0.05) in the furrows, receiving the lower rate of N fertiliser compared with the highest rate, with less frequent reductions observed in the third crop (canola); losses of N 2 O from the beds was unaffected by N rate, perhaps from nitrate leakage into the adjacent furrow of the raised bed experiment. On the nearby flat experiment, nitrate leaching may have diminished the effects of N rate and DCD on N 2 O flux. Furthermore the extra N did not significantly increase grain yield in either the wheat or canola crops on both experiments. The application of DCD in the canola crop temporarily reduced ( P  < 0.05) N 2 O production by up to 84 % from the beds, 83 % in the adjacent furrows and 75 % on the flat experiment. Grain yield was not significantly ( P  < 0.001) affected however, canola income was reduced by $1407/ha and $1252/ha, compared with no addition of inhibitor on the respective bed and flat experiments. Although N 2 O fluxes are driven by environmental episodic events, management will play a role in N 2 O abatement. However, DCD currently appears economically unfeasible and matching N fertiliser supply to meet crop demand appears a better option for minimising N 2 O losses from high rainfall cropping systems.

Superfund, one of the main programs used by the Environmental Protection Agency to clean up serious, often abandoned, hazardous waste sites, has been improved considerably in recent years. Notably, progress has been made in two important areas: the development of risk assessments that are scientifically valid yet flexible, and the development and implementation of better treatment technologies.

One of the most contentious aspects of Superfund cases is the allocation of response costs among potentially responsible parties. The statute allows courts to consider a variety of equitable factors, but the task is often complicated by incomplete data and missing parties. This Article reviews the case law and the practical problems faced by parties engaged in cost allocations. It describes some practical approaches, including formulas for evaluating and weighing the relevant factors, to assist practitioners in achieving reasonably fair allocations without excessive transaction costs

Under the amended law, cleanup of hazardous waste sites may be a real possibility.