Chemische Zusammensetzung zweier quellnaher Waldbäche im Hochschwarzwald — Abflussabhängige Variabilität und Einfluss einer Bodenkalkung     

Martin Armbruster  Hayo Köhler  Karl-Heinz Feger 《European Journal of Forest Research》2000,119(1-6):249-262

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Methode zur Integration der Naturraum-Inanspruchnahme in Ökobilanzen     

Martin Baitz  Johannes Kreissig  Marc-Andree Wolf 《European Journal of Forest Research》2000,119(1-6):128-149

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Voluntary environmental initiatives: ISO14001 certified organisations in Singapore     

Sanjeev Singh  Martin Perry 《Asia Pacific viewpoint》2000,41(3):269-278

The value of environmental regulation through command and control measures has been questioned because of inflexibility and high cost. Voluntary environmental initiatives have been proposed as an alternative approach to save costs, overcome problems of inadequate enforcement and monitoring and to take advantage of the environmental leadership of transnational corporations (TNCs). Amongst voluntary environmental initiatives certified environmental management system standards have so far had most impact in Singapore and the rest of Southeast Asia. This paper investigates the environmental policy statements of 52 ISO14001 certified organisations in Singapore and shows that the environmental commitments being made are no substitute for traditional environmental regulations.  相似文献   

Colorimetric determination of arprinocid in feed.     

D W Fink  R P Martin  J V Pivnichny  J S Shim 《Journal of the Association of Official Analytical Chemists》1978,61(5):1078-1082

An analytical method has been developed for the determination of arprinocid (9-(2-chloro-6-fluorophenylmethyl)-9H-purin-6-amine) in feed, based upon measurement of the absorbance of the diazo chromophore formed from a product of zinc reduction of the drug in acidic solution. The analyte is extracted from the feed into chloroform in the presence of a pH 7 phosphate buffer and isolated by adsorption chromatography on alumina, followed by partitioning between hexane and 0.15M HCl. The reduction product in the aqueous phase is then treated for colorimetric measurement. This procedure has been applied to determining 0.0010--0.0080% arprinocid in feed with a precision of less than 5% relative standard deviation near the middle of this concentration range. Of 32 feed additives examined, only zoalene and sulfamethazine were serious interferences. A study and discussion of several factors, e.g., reaction time, pH, and amount of zinc metal, that affect the analytical reactions are also included.  相似文献   

Carbon loss from roots of wheat cultivars     

J.K. Martin  J.R. Kemp 《Soil biology & biochemistry》1980,12(6):551-554

The amounts of organic materials released into soil from roots during the first 4 weeks of growth were determined for 11 cultivars of wheat (Triticum aestivum L.). Carbon loss from roots was measured by supplying ¹⁴CO₂ continuously to the shoots and measuring the ¹⁴C content of the roots, root-free soil, water-soluble material and CO₂ flushed from the root chamber. Six cultivars were compared in each of two experiments, with the cultivar Condor common to both experiments. There were no significant differences between cultivars, relative to Condor, for ¹⁴C activity present in soil, roots, water-soluble material or rhizosphere CO₂. There was a significant difference between cultivars in experiment 1, but not in experiment 2, for the variate log₁₀ (¹⁴C lost from roots: ¹⁴C translocated to roots).There was evidence that a reduction in growth temperature, within the range 10–15°C, increased carbon loss from wheat roots into the rhizosphere.  相似文献   

Decomposition of algal cells and components and their stabilization through complexing with model humic acid-type phenolic polymers     

L. Verma  J.P. Martin 《Soil biology & biochemistry》1976,8(2):85-90

Axenic cultures of Anacystis, Microcoleus, Plectonema and Synechococcus isolated from Greenfield sandy loam and of Anabaena flos-aquae, Nostoc muscorum and Chlorella pyrenoidosa from other sources were cultured under light and constant aeration and with [U-¹⁴C]-glucose in the nutrient medium. Whole cells, cell walls, cytoplasm and extracellular polysaccharides of selected species readily decomposed in the soil and after 22 weeks between 61 and 81% of the added C had evolved as CO₂. Complexing of cell wall and cytoplasmic preparations from A. flos-aquae and N. muscorum with model humic acid-type phenolic polymers reduced decomposition of the cell walls by 40% and of the cytoplasm by 70%. Over 50% of the residual 14C activity in the soil amended with whole algal cells remained in the 0.5% NaOH-extracted soil. With exception of Microcoleus sp. more of the residual ¹⁴C from cell walls, cytoplasm and polysaccharide fractions was present in the humic acid or fulvic acid fractions.  相似文献   

Effect of montmorillonite and humate on growth and metabolic activity of some actinomycetes     

J.P. Martin  Z. Filip  K. Haider 《Soil biology & biochemistry》1976,8(5):409-413

In well-aerated culture solutions Ca-montmorillonite at 0.25% concentration markedly accelerated and increased growth, glucose consumption and CO₂ evolution by various Streptomyces, Micromonospora and Nocardia species. The montmorillonite was a little more active than Ca-humate and was usually still but somewhat less effective when confined to dialysis tubing. Ca-exchange resin, Na₂SiO₃ and finely powdered CaCO₃ exerted very little or no effect. In many cultures the relation of glucose consumption to biomass formation indicated a more efficient use of the glucose C for cell synthesis in the presence of clay. In other cultures the greater biomass formation was associated with a more rapid and complete utilization of the glucose present.  相似文献   

Factors influencing the loss of organic carbon from wheat roots     

J.K. Martin 《Soil biology & biochemistry》1977,9(1):1-7

Wheat plants were grown in an atmosphere containing ¹⁴CO₂ at temperatures of 10°C or 18°C for periods from 3–8 weeks. The plant roots were maintained under sterile or non-sterile conditions in soil contained in sealed pots which were flushed to displace respired ¹⁴CO₂. The ¹⁴C content of the shoots, roots and soil was measured at harvest. The loss of ¹⁴C from the roots, expressed either in terms of total ¹⁴C recovered from the pots or ¹⁴C translocated to the roots, ranged from 14.3–22.6%, mean 17.3% or 29.2–44.4%, mean 39.2%, respectively. The presence of soil microorganisms significantly increased ¹⁴CO₂ release from the rhizosphere but had no effect on the ¹⁴C content of the soil. Fractionation of 6 m HC1 hydrolysates from sterile and non-sterile soils showed the presence in all soils of material behaving as neutral sugars and amino acids, in quantities representing 5.9–9.2% and 13.4–17.2% of the soil ¹⁴C content for the sugar and amino acid fractions respectively. It is proposed that a major loss of root carbon resulted from autolysis of the root cortex. Root lysis was increased by soil microorganisms, apparently without penetration of the plant cell walls.  相似文献   

Effect of soil moisture on the release of organic carbon from wheat roots     

J.K. Martin 《Soil biology & biochemistry》1977,9(4):303-304

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COMPETITION BETWEEN PERENNIAL RYEGRASS AND MEADOW FESCUE UNDER FIELD-PLOT CONDITIONS     

R. L. Crocker  P. M. Martin 《Grass and Forage Science》1964,19(1):27-29

Perennial ryegrass and meadow fescue were grown alone and in association in field plots, to gain an idea of the nature and importance of the competitive interactions between them, and their relative contributions to the yield of the newly-established sward.
Experiments over 10 weeks and 9 months both showed that the contribution by fescue to the overall dry-matter yield was severely restricted by perennial ryegrass. There were no deaths of fescue plants during the experimental period (which included an overwintered treatment). The depression in yield was rather a result of a marked decrease in size and weight of the individual plants, brought about by competition for light and nutrients from the faster-growing ryegrass.  相似文献