Prolonged Testing of Metal Mobility in Mining-Impacted Soils Amended with Phosphate Fertilisers

The aim of the study was to determine whether the application of superphosphate fertiliser to soils contaminated with mine wastes can inhibit metal and metalloid mobility (Cu, Pb, Zn, Cd, Fe, Mn, As, Sb) in the long term. Contaminated soils contained sulfide- and sulfate-rich waste materials from the Broken Hill and Mt Isa mining centres. Results of long-term (10 months) column experiments demonstrate that fertiliser amendment had highly variable effects on the degree of metal and metalloid mobilisation and capture. Rapid release of metals from a sulfate-rich soil showed that phosphate amendment was ineffective in stabilising highly soluble metal-bearing phases. In a sulfide-rich soil with abundant organic matter, complexing of metals with soluble organic acids led to pronounced metal (mainly Cd, Cu and Zn) release from fertiliser-amended soils. The abundance of pyrite, as well as the addition of fertiliser, caused persistent acid production over time, which prevented the formation of insoluble metal phosphate phases and instead fostered an increased mobility of both metals and metalloids (As, Cd, Cu, Sb, Zn). By contrast, fertiliser application to a sulfide-rich soil with low organic carbon content and a sufficient acid buffering capacity to maintain near-neutral pH resulted in the immobilisation of Pb in the form of newly precipitated Pb phosphate phases. Thus, phosphate stabilisation was ineffective in suppressing metal and metalloid mobility from soils that were rich in organic matter, contained abundant pyrite and had a low acid buffering capacity. Phosphate stabilisation appears to be more effective for the in situ treatment of sulfide-rich soils that are distinctly enriched in Pb and contain insignificant concentrations of organic matter and other metals and metalloids.     

Phosphorus bioavailability of biochars produced by thermo‐chemical conversion

Recycling of P is a common strategy in efficient use of P. The aims of our investigation were to study the P extractability of biochars produced by low temperature conversion and to determine the effect of soda application on low‐temperature conversion of organic compounds and the bioavailability of P to rye grass (Lolium perenne L., cv. Grazer). In this study canola cake, dried distillers grains with solubles, and meat‐and‐bone meal were converted to biochars with thermo‐chemical conversion at 400°C. The P availability was measured in terms of solubility in water, 2% citric, and 2% formic acid, and in a pot experiment with rye grass (Lolium perenne L.) which was cut three times. Application of 8% (w/w) soda to the process of thermo‐chemical conversion of canola cake, dried distillers grains with soluble and meat‐and‐bone meal resulted in an increase of water‐, 2% citric‐, and 2% formic‐acid‐extractable P in the biochars. In contrast to the application of soda, addition of 12% wood ash (w/w) to the conversion of dried distillers grains with solubles resulted in a lower increase of water‐soluble P in the corresponding biochar compared to processing biochar without additives. Addition of biochar P (100 mg P [kg soil]^–1) to a Luvisol resulted in an increase of CAL‐extractable soil P. The P uptake of rye grass from biochars produced with the addition of soda was as effective as basic slag and MgNH₄ phosphate fertilizers and even better than rock phosphate.     

Die Rolle der Ertragssteigerung im Anpassungsprozess der Landwirtschaft

Measures undertaken in the Federal Republic of Germany to rationalize agricultural production, viz. a reduction of intensive farming, simplification of farm production methods, and the introduction of specialization and mechanization, have been carried to their near completion in modern agricultural holdings. It is now necessary to introduce a new overriding economic principle if we are to successfully meet further wage increases and price reductions and improve the income level of the agricultural population. A new farm management concept based on the idea of a radical increase in specific intensive production methods is now being developed. In view of the high fixed costs in West German agriculture, the degression of fixed costs per production unit outweights the progression of variable costs when output is increased. In other words, higher yields per hectare and animal effect a decrease in unit costs. Nitrogen fertilizer being the most important factor in output increase, its profitable level is examined by means of six marginal value analyses. The fertilizer optimum is reached when marginal costs and marginal yields balance each other out. In all six examples this optimum coincides almost exactly with the point of maximum yield per hectare. This simplifies the problem considerably, at least under the conditions established for six examples. The optimal input level of nitrogen fertilizer does not have to be determined by means of a complicated marginal value analysis. It lies just under the maximum yield per hectare. We cannot expect that price-cost alterations will push this fertilizer optimum up within the near future. However, we may assume that new possibilities will open up for nitrogen fertilizer. In the first place, the majority of the agricultural holdings are still a long way from having reached the fertilizer optimum now economically feasible. Secondly, the present level of fertilizer optimum is constantly being raised as the result of technological advances. It is the task of economic counselling to achieve the fullexploitation of available earning power resources and the task of scientific research todevelop new earning power resources. The exploitation and the development of earning power resources can have very positive results in the case of inorganic fertilizer, since through its application it is possible to even out income disparities in agriculture

—help small holdings in particular, mineral fertilizer being a divisible input factor

—come closer to a solution of the central probrem of the agriculture of the Federal

—Republic of germany, that of combining high labour productivity with high soil productivity.

     

Use of C-reactive protein to predict outcome in dogs with systemic inflammatory response syndrome or sepsis

Background – There is a high mortality rate in patients with systemic inflammatory response syndrome (SIRS) or sepsis. Therefore, an early diagnosis and prognostic assessment is important for optimal therapeutic intervention. The objective of the study was to evaluate if baseline values and changes in serum C-reactive protein (CRP) might predict survival in dogs with SIRS and sepsis.
Design – Prospective study; July 2004 to July 2005.
Setting – Small Animal Clinic, Berlin, Clinic of Small Animal Medicine, Munich.
Animals – Sixty-one dogs.
Measurements and Main Results – For the CRP analysis blood was drawn on day 0, 1, and 2; CRP was measured using a commercial ELISA test kit. Thirteen dogs suffered from nonseptic SIRS and 48 dogs from sepsis. The 14-day survival rate was 61% (69% nonseptic SIRS, 58% sepsis). Serum CRP was higher in sick dogs compared with controls ( P <0.001). Over the 3-day period surviving dogs ( n =31) displayed a significantly greater decrease in CRP than nonsurvivors ( n =10) ( P =0.001). No correlation was found between the initial CRP concentrations and the survival rate. The changes in CRP corresponded to the survival rate ( P =0.01).
Conclusion – There was no significant relationship between the survival rate in dogs with nonseptic SIRS or sepsis and the initial serum CRP concentrations. There was a correlation between decreasing CRP concentrations and recovery from disease. However, the changes in CRP concentrations over a 3-day period correctly predicted survival in 94% of dogs and death in 30% of the dogs (false positive rate 22%).     

Molecular characterization of PRR13 and its tissue-specific expression in rainbow trout (<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>)

The proline-rich protein 13 (PRR13) is reported to be a key regulator of the resistance to cytostatica by decreasing the copy number of the proapoptotic gene thrombospondin-1. We isolated and characterized the complete PRR13 gene sequence of rainbow trout (Oncorhynchus mykiss). The gene comprises four exons and three introns, the latter of comparatively short lengths (100–811 bp). The full-length PRR13 cDNA consists of 1,101 nucleotides, including an open reading frame of 563 bp, which is predicted to encode a 187 amino acid protein with a molecular mass of 18.8 kDa. A continuous stretch of ten serine residues at the C-terminus is highly conserved and characteristic for vertebrate PRR13, but not for other known proline-rich proteins. Phylogenetic analyses suggest a clear separation of teleostean PRR13 proteins and those from mammalian and reptilian species. Comparison of the tissue-specific PRR13 mRNA abundance in two strains of the rainbow trout coastal form (TCO Steelhead II-WA vs. BORN Steelhead II-Germany) revealed an increased expression in the BORN trout in nearly all examined tissues. The major expression differences were detected in gill (2.29-fold) and in liver tissue (2.16-fold). Hence, the increased PRR13 expression in BORN trout might cause improved protection from natural cytostatica and therefore support our assumption that PRR13 is a candidate gene possibly involved in the varying ability of the two rainbow trout strains to handle environmental stress under local conditions of the Southern Baltic.