Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Journal of Chromatography A 643 (1993), S. 261-270 
    ISSN: 0021-9673
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Journal of Chromatography A 509 (1990), S. 141-146 
    ISSN: 0021-9673
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Biology and fertility of soils 22 (1996), S. 53-58 
    ISSN: 1432-0789
    Keywords: Key words Dehydrogenase activity ; Heavy metal content ; Phosphatase activity ; Lead ; Soil pollution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We studied the effects of Pb pollution on soil dehydrogenase and phosphatase activity. Samples of four soils (Saxe, Podestà, Porto Teulada, and Sa Xia Manna) were collected from various locations in southwestern Sardinia, Italy. The soils, which differ mainly in heavy metal contents of pedologic origin (Cu, Zn, Cd, and Pb), were treated with Pb (0, 100, 500, 1000, and 5000 μg Pb g–1 soil) and incubated in the laboratory. Samples of the incubated soils were collected periodically (0, 1, 2, 4, 8, and 16 weeks) and the enzymes were measured. Soil dehydrogenase activity was influenced by both the Pb additions and variations in soil moisture content. Only the addition of 5000 μg Pb g–1 soil led to a significant decrease in dehydrogenase activity compared to the controls, while the other doses of Pb did not always result in a clear reduction in enzyme activity. Drying the soil led to a considerable reduction in dehydrogenase activity, sometimes so far as to render the differences found between the various treatments not statistically significant. Soil phosphate activity was also influenced by the Pb additions, but the effect of the variation in soil moisture content was less than that found for the dehydrogenase. After the 2nd week of incubation, the phosphate activity in the Podestà and Saxe soils had decreased proportionally to the increase in Pb content. At the end of the incubation period, in the Porto Teulada and Sa Xia Manna soils, a net reduction in phosphatase activity versus controls was found only at the highest Pb concentration. Although both enzyme activities were influenced by the Pb additions, the phosphate activity was less sensitive to variations in the soil moisture content and may thus be a more suitable indicator for soil pollution by Pb.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Nutrient cycling in agroecosystems 25 (1990), S. 167-174 
    ISSN: 1573-0867
    Keywords: Enzymatic hydrolysis ; humified materials ; humification parameters ; organic carbon ; organic fertilizers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract An enzymatic approach to assess the stability of organic matter extracted from organic fertilizers and amendments is proposed. The use of 0.1M NaOH plus 0.1M Na4P2O7 previously suggested as a suitable extractant solution for soil organic matter was also found satisfactory for the extraction of organic matter from organic fertilizers and amendments, especially when the temperature was raised to 65°C. The presence of nonhumified compounds in the extracts from organic fertilizers may interfere considerably during fractionation of organic carbon. An enzymatic hydrolysis with lipase, lysozyme and pronase, added sequentially to the extracts, led to an appreciable reduction in the interference. The interference was further reduced by carrying out a successive acid hydrolysis with 3N H2SO4; in this case the DH values (percentage of humified fractions with respect to total extractable carbon) were reduced to less than 10% in all organic fertilizers, but remained higher than about 70% in organic amendments.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1573-0867
    Keywords: Organic fertilizers ; electrofocusing (EF) ; humified substances
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The objectives of the study were to test the electrofocusing technique to determine its suitability as a method for the characterization of organic fertilizers from a qualitative point of view and identification of the organic matrix in an unknown fertilizer; no laboratory methods for this purpose are presently available. Analytical electrofocusing (EF) is shown to fulfill these objectives and may be easily adopted as a routine manual procedure. A solution of sodium hydroxide was chosen as the extractant because it allows comparisons between various types of humified materials and permits the evolution of organic matter to be followed during “maturation” of the fertilizer itself. The organic fertilizers considered included many nitrogen-rich waste materials, mostly of animal origin. They are divided into different groups according to origin and EF profiles.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1573-0867
    Keywords: Nutrient content ; tolerance exploitation ; superphosphate ; t-test ; Wilcoxon test ; fertilizers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A given tolerance value on the declared nutrient content of fertilizers is permitted by some national laws. A statistical method to assess systematic exploitation of tolerance values by single nutrient fertilizer producers is proposed. Production of superphosphate was selected as the case study. The method was tested on a yearly production, on randomly selected samples, and on a generated series of samples; it was found to be simple and reliable. The method is theoretically expected to be more reliable than the Wilcoxon test recommended by French law for normal distributions; it appears to fit better than the Wilcoxon test to uneven production of fertilizers.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Nutrient cycling in agroecosystems 44 (1995), S. 65-72 
    ISSN: 1573-0867
    Keywords: Cr ; hurnification parameters ; isoelectric focusing ; leather meal ; mineralization ; organic fertilizer ; organic matter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Leather meal fertilizer was mixed with a soil (Typic Xerorthent) and incubated in the laboratory for one year at room temperature. Soil samples were collected periodically and analyzed in order to follow the transformation of the organic matter as well as the availability of Cr and certain plant nutrients. The results obtained showed intense mineralization during the first 60–120 days of the incubation period. The amount of humic acids (HAs) separated from the alkaline extracts showed that the humification level increased markedly after the first 60 days of incubation and, as shown by IEF analysis, organic compounds similar to the soil humic substances were formed. Variations in the amount of available nutrients were observed; only the extractable Cr increased during the first period of mineralization.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Nutrient cycling in agroecosystems 44 (1995), S. 225-230 
    ISSN: 1573-0867
    Keywords: humic extracts ; humification parameters ; isoelectric focusing ; leonardite ; organic fertilizers ; peat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Several samples of peat and leonardite (organic fossil material of vegetable origin) and of humic extracts from peat and leonardite were characterized using some humification parameters and isoelectric focusing (IEF). The HA/TOC and the humification rate (HR) show values lower than 60% for peat and higher than 70% for leonardite samples. These two parameters are useful to distinguish peat from leonardite, but unable to identify the organic materials in the humic extracts. Peat an leonardite samples and their humic extracts were characterized using IEF and evaluating the quantitative distribution of the bands of the profile. The group of bands in the range from pH 4.8 to 5.5 (region C) is characteristics in all samples. In particular, the relative area is less than 55% for peat and humic extracts from peat and higher than 60% for leonardite and humic extracts from leonadite.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Nutrient cycling in agroecosystems 44 (1995), S. 249-253 
    ISSN: 1573-0867
    Keywords: Blood meal ; organic fertilizers ; organic-mineral fertilizers ; hemoglobin ; heme ; spectrophotometric characterization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A simple and useful analytical method is proposed for the characterization of blood meal fertilizer, a quality organic fertilizer commonly used in agriculture. Despite the agronomical and commercial importance of this organic fertilizer, Italian law does not indicate an analytical method for its identification in organic matrices. This situation is very unsatisfactory because unscrupulous producers could declare the presence of a quality organic fertilizer, such as blood meal, instead of a poorer fertilizer. In this work the heme group of the hemoglobin contained in blood meal was characterized spectrophotometrically and a calibration curve prepared using different concentrations of hemoglobin was used to determine the hemoglobin content in six blood meal samples. The method was successfully applied for the qualitative identification of hemoglobin in mixtures of organic and/or organic fertilizers with small amounts (3–10%) of blood meal.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Biology and fertility of soils 22 (1996), S. 53-58 
    ISSN: 1432-0789
    Keywords: Dehydrogenase activity ; Heavy metal content ; Phosphatase activity ; Lead ; Soil pollution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We studied the effects of Pb pollution on soil dehydrogenase and phosphatase activity. Samples of four soils (Saxe, Podestà, Porto Teulada, and Sa Xia Manna) were collected from various locations in southwestern Sardinia, Italy. The soils, which differ mainly in heavy metal contents of pedologic origin (Cu, Zn, Cd, and Pb), were treated with Pb (0, 100, 500, 1000, and 5000 μg Pb g-1 soil) and incubated in the laboratory. Samples of the incubated soils were collected periodically (0, 1, 2, 4, 8, and 16 weeks) and the enzymes were measured. Soil dehydrogenase activity was influenced by both the Pb additions and variations in soil moisture content. Only the addition of 5000 μg Pb g-1 soil led to a significant decrease in dehydrogenase activity compared to the controls, while the other doses of Pb did not always result in a clear reduction in enzyme activity. Drying the soil led to a considerable reduction in dehydrogenase activity, sometimes so far as to render the differences found between the various treatments not statistically significant. Soil phosphate activity was also influenced by the Pb additions, but the effect of the variation in soil moisture content was less than that found for the dehydrogenase. After the 2nd week of incubation, the phosphate activity in the Podestà and Saxe soils had decreased proportionally to the increase in Pb content. At the end of the incubation period, in the Porto Teulada and Sa Xia Manna soils, a net reduction in phosphatase activity versus controls was found only at the highest Pb concentration. Although both enzyme activities were influenced by the Pb additions, the phosphate activity was less sensitive to variations in the soil moisture content and may thus be a more suitable indicator for soil pollution by Pb.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...