Phosphorus Nutrition on Leaching Sands.

The excessive amounts of nutrients entering the Peel-Harvey Estuarine system have resulted in a marked increase in the abundance of algal species .within the estuary and reduced production on the sandy coastal soils of the catchment from which the nutrients are being leached. Recent stream samplings by D.C.E have shown that the deep grey Bassendean sands may be contributing up to 40 per cent of the total P loading in the Harvey River. Agriculture Department trials around Albany on similar sands have shown that up to 80 per cent of the bicarb extractable P may be lost after only 150 mm of rain. Phosphorus rundown trials. 82HA14, 82HA15, 82HA16, 82HA17, 82HA18. Soil test calibration curve trials. 82HA20, 82HA21, 82HA22, 82HA23, 82HA24, 82HA25, 82HA26, 82HA27, 82HA28, 82HA29, 82HA30. P sources x rates x times of application trials. 82HA31, 82HA32. P sources leaching trials. 82HA33, same site as 82HA31, 82HA34, same site as 82HA32. Lime rates with + P. 82HA36, 82HA37, 82HA38, Old land same site as 82HA28. Overall summary. The reverted superphosphates are at least as good as normal superphosphate as far as pasture yield and P uptake are concerned, however bicarb P results indicate considerably less leaching. The very insoluble phosphate areas do not leach to any degree but are less efficient than superphosphate in pasture nutrition. The performance of these less leachable sources is expected to improve relative to superphosphate in subsequent years. The two leaching trials show that there is little difference in P leaching on new and old land sites, however the build-up of organic material on old land appears to have a marked effect on Potassium retention. In 1983 all treatments in the soil test calibration curve trials should have different residual values of P and splitting each plot into untreated and adequately supplied halves should give many points for the soil test calibration curves. From the three trials reported here it would appear that there is no interaction between P nutrition and added lime, however improved pasture management on these trials in 1983 should give more data

Phosphorus nutrition of high rainfall pastures - Peel Harvey estuarine system study (phase II) and related phosphorus work

A. Sources, rates, time of application of phosphorus on high rainfall pastures. 80AL2, 80AL5, 81AL5, 81AL6, 81KE2, 81MA4, 82AL10, 82HA31, 82HA32, 83HA26, 83HA27. B. Soil test calibration curve trials on Bassendean sands. 82HA20, 82HA21, 82HA22, 82HA23, 82HA24, 82HA25, 82HA26, 82HA27, 82HA28, 82HA29, 82HA30. C. Soil test calibration curve trials on Coolup sands. 83HA20, 83HA21, 83HA22, 83HA23, 83HA24, 83HA25. D. Phosphorus rundown. 82HA14, 82HA15, 82HA16, 82HA18. NOTE: Summary is in two parts. 1. Peel Harvey catchment program (Deeley, Barker). 2. General program on high rainfall sandy soils (Yeates, Clarke). Summary of Experimental Work. General Aims. The work summarized here was commenced with the following aims: 1. To improve the efficiency of agricultural utilization of phosphorus applied to pastures on the deep leaching sands of the high rainfall areas. 2. To minimize phosphorus loss to drainage from the deep sand, and thus reduce eutrophication problems in adjacent waterways. Five potential ways of reducing the phosphorus losses from fertilizer sources while still maintaining optimum level of agricultural productivity were considered possible. These were: 1. The use of accurate soil tests for predicting phosphorus requirements and thus ensuring that only phosphorus actually required is applied. 2. Modification of times of application of soluble phosphorus fertilizer to maximise the plant utilisation.of applied P, and to minimise losses. 3. Development of phosphorus fertilizers of lower water solubility than ordinary superphosphate (and hence with reduced leaching losses). 4. Use of deep rooted and/or perennial plant species which are better able to utilize applied soluble P. 5. Modification of the sandy soils to increase phosphorus adsorption capacity and hence reduce or eliminate leaching losses. To date research has been chiefly concerned with the first three of these possibilities

Modifying fertiliser practices

If modified fertiliser practices are adopted phosphorus losses from the Peel-Harvey catchment can be reduced. Farmers can save money on fertiliser applications and the need for more expensive catchment management measures to reduce algal pollution of the estuary will be avoided. Research data available so far indicate that, with farmer co-operation and the use of the new slow release fertiliser New Coastal Superphosphate, long-term phosphorus application rates can be reduced by 30-40 per cent - and possibly even halved - without lowering agricultural production. This will also reduce phosphorus loss to drainage water. Although much of the research since 1982 has concentrated on the Peel-Harvey catchment, many of the results apply to all of the high rainfall coastal belt between Perth and Albany. Already farmers throughout this area have benefited from the researc

Rock phosphates : fertilisers for sandy soils?

Rock phosphates, from which water solubls phosphorus fertilisers such as superphosphate are manufactured, sometimes appear attractive to farmers because of their relatively low cost. But redearch has shown t6hat on most western australian soils they are not economical fertilisers. However, some deep sandy soils of the State\u27s high rainfall area are exeptions. On these soils, rock phosphates compare favourably with superphosphate for plant growth. But how can these deep sands be identified. This article describes research to define the soil characteristics necessary for rock phosphates and fertilisers containing rock phosphate, such as Coastal superphosphate, to be effective substitutes for superphosphate

A study of psychiatrists’ concepts of mental illness

Background: There are multiple models of mental illness that inform professional and lay understanding. Few studies have formally investigated psychiatrists' attitudes. We aimed to measure how a group of trainee psychiatrists understand familiar mental illnesses in terms of propositions drawn from different models. Method: We used a questionnaire study of a sample of trainees from South London and Maudsley National Health Service (NHS) Foundation Trust designed to assess attitudes across eight models of mental illness (e.g. biological, psychodynamic) and four psychiatric disorders. Methods for analysing repeated measures and a principal components analysis (PCA) were used. Results: No one model was endorsed by all respondents. Model endorsement varied with disorder. Attitudes to schizophrenia were expressed with the greatest conviction across models. Overall, the ‘biological’ model was the most strongly endorsed. The first three components of the PCA (interpreted as dimensions around which psychiatrists, as a group, understand mental illness) accounted for 56% of the variance. Each main component was classified in terms of its distinctive combination of statements from different models: PC1 33% biological versus non-biological; PC2 12% ‘eclectic’ (combining biological, behavioural, cognitive and spiritual models); and PC3 10% psychodynamic versus sociological. Conclusions: Trainee psychiatrists are most committed to the biological model for schizophrenia, but in general are not exclusively committed to any one model. As a group, they organize their attitudes towards mental illness in terms of a biological/non-biological contrast, an ‘eclectic’ view and a psychodynamic/sociological contrast. Better understanding of how professional group membership influences attitudes may facilitate better multidisciplinary working

Phosphorus nutrition of high rainfall pastures - Peel Harvey estuarine system study

1. Field experiments. A. Sources, rates, time of application of phosphorous on high rainfall Pastures - 80AL2, 80ALS, 81AL5, 81AL6, 81KE2, 81MA4, 82AL10, 82HA31, 82HA32, 83HA26, 83HA27. B. Soil test calibration curve trials. 82HA20, 82HA26, 82HA29, 83HA20, 83HA21, 83HA22, 83HA23, 83HA24, 83HA25. C. P sources and rates on sandy soils of the high rainfall areas - 84AL33, 84AL34, 84HA18, 84HA25. D.Maintenance P trials - 84AL32, 84HA17, 84HA24, 84HA28. 2.Glasshouse Experiments. 84GL5 - 1. Phosphorus sources on subterranean clover on sandy soils. 2. Soil test calibration experiment

Phosphorus nutrition of high rainfall pastures, Sulphur nutrition of pastures and Sulphur - low rainfall.

Phosphorus nutrition of high rainfall pastures - Peel Harvey Estuarine System Study and related phosphorus work. (1) Sources, rates, time of application of phosphorous on high rainfall pastures. 81AL5, 81AL6, 82AL10, 82HA32, 83HA26, 83HA27. (2) P sources and rates on sandy soils of the high rainfall areas. 84AL33, 84AL34, 84HA18, 84HA25. (3) Maintenance rate of P on pastures on sandy soils. 84AL32, 84HA17, 84HA24, 84 HA28. Sulphur nutrition of pastures A. Sulphur - high rainfall (2684 EX/4054EX) (1) Sources, rates, time of application of sulphur to pastures. 80AL4, 80AL4B (2) S sources and rates on pastures on sandy soils of the high rainfall areas. 84HA20, 84HA27 (3) Maintenance rate of S on pastures on sandy soils. 84AL35, 84HA19, 84HA26 B. Sulphur - low rainfall (1) Sulphur on pastures. 82AL9, 82KA4 (2) Sulphur requirements of wheat. 85TS24 81AL5, 81AL6, 82AL10, 82HA32, 83HA26, 83HA27, 84AL33, 84AL34, 84HA18, 84HA25, 84AL32, 84HA17, 84HA24, 84HA28, 80AL4, 80AL4B, 84HA20, 84HA27, 84AL35, 84HA19, 84HA26, 82AL9, 82KA4, 85TS24

Fluid observers and tilting cosmology

We study perfect fluid cosmological models with a constant equation of state parameter $\gamma$ in which there are two naturally defined time-like congruences, a geometrically defined geodesic congruence and a non-geodesic fluid congruence. We establish an appropriate set of boost formulae relating the physical variables, and consequently the observed quantities, in the two frames. We study expanding spatially homogeneous tilted perfect fluid models, with an emphasis on future evolution with extreme tilt. We show that for ultra-radiative equations of state (i.e., $\gamma>4/3$), generically the tilt becomes extreme at late times and the fluid observers will reach infinite expansion within a finite proper time and experience a singularity similar to that of the big rip. In addition, we show that for sub-radiative equations of state (i.e., $\gamma < 4/3$), the tilt can become extreme at late times and give rise to an effective quintessential equation of state. To establish the connection with phantom cosmology and quintessence, we calculate the effective equation of state in the models under consideration and we determine the future asymptotic behaviour of the tilting models in the fluid frame variables using the boost formulae. We also discuss spatially inhomogeneous models and tilting spatially homogeneous models with a cosmological constant