排序方式: 共有3条查询结果,搜索用时 15 毫秒
1
1.
In pot experiments cuttings of grapevine rootstock cultivar 5C were grown on a soil from a grapevine nursery affected with replant disease (replant soil) and on a similar soil that had not been planted with grapevines before (non-replant soil). Plants were also inoculated with the vesicular-arbuscular (VA) mycorrhizal fungus,Glomus mosseae, or left without mycorrhizal fungus inoculation. Shoot and root growth, mycorrhization of roots and numbers of total aerobic bacteria and fluorescent pseudomonads on the rhizoplane of grapevines were determined at several sampling dates. On replant soil, numbers of fluorescent pseudomonads on the rhizoplane were higher compared to non-replant soil, before differences in shoot and root weight between replant and non-replant soil occurred. Without inoculation withG. mosseae, the mycorrhization of roots was much lower on replant soil (13%) than on non-replant soil (51%). On replant soil, inoculation withG. mosseae increased mycorrhization to 39% and increased shoot length, leaf area and shoot weight. The beneficial effect of VA-fungus inoculation on replant soil was not due to increased nutrient concentrations in leaves. On replant soil, the inoculation withG. mosseae reduced the number of fluorescent pseudomonads on rhizoplane of grapevine, while the numbers of total aerobic bacteria were not influenced by inoculation withG. mosseae. These results suggest a direct or indirect role of fluorescent pseudomonads in replant disease of grapevine. 相似文献
2.
Many mine spoils present at the surface of reclamation sites in the Lower Lusatian mining district are carboniferous substrates,
i.e. contain geogenic organic matter. Depending on its susceptibility to microbial degradation, geogenic organic matter might
influence the establishment of a carbon requiring microflora in mine spoils. As geogenic organic matter contains substantial
amounts of organic nitrogen it is also a potential source for plant available N. The objective of the present study was to
quantify C and N mineralisation and microbial biomass in geogenic organic matter present at reclamation sites in Lower Lusatia.
We also studied, whether these properties can be influenced by raising the originally low pH to near neutral conditions. In
laboratory incubation studies, the rates of CO2 evolution and net N mineralisation were determined in geogenic organic matter and carboniferous mine spoil with and without
addition of lime. At the same time, microbial biomass carbon was estimated. As a reference, soil organic matter originating
from the humus layer of a 60-year-old Pinus sylvestris stand was used. As indicated by the initial rates of C mineralisation,
geogenic carbon was microbially available but to a lower extent than soil organic carbon. During incubation, C mineralisation
remained constant or tended to increase with time, depending on the origin of the sample, while it decreased in soil organic
matter. Unlike in soil organic matter, in geogenic organic matter and carboniferous mine spoil, C mineralisation was not consistently
promoted by lime addition. Prior to incubation, microbial biomass in geogenic organic matter and carboniferous mine spoil
was about 10-fold lower than in soil organic matter and tended to increase with incubation time while it decreased in soil
organic matter. Similar to C mineralisation, microbial biomass in geogenic organic matter increased after liming, while it
declined in carboniferous mine spoil immediately after lime addition. Rates of net N mineralisation were very low in geogenic
organic matter and carboniferous mine spoil regardless of the length of incubation and could not be enhanced by raising the
pH. It was concluded, that in mine spoils where accumulation of soil organic matter has not yet occurred, geogenic organic
matter can be favourable for the establishment of a heterotrophic microflora. However, in the short term, geogenic matter
is no source for plant available N in mine spoils.
This revised version was published online in June 2006 with corrections to the Cover Date.
This revised version was published online in June 2006 with corrections to the Cover Date.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
3.
The impact of organic waste material and fly ash on microbial and chemical pyrite oxidation was investigated in a field experiment,
as well as in column tests under laboratory conditions. For the field experiment, pyritic mine spoil was ameliorated with
fly ash and treated either with mineral fertiliser, with sewage sludge or with compost. Independent of treatment, during the
18 months following application, the pyrite-S contents decreased steadily in the top spoil (0–30 cm depth). However, high
variations of the pyrite-S content were observed. Compared to other pyrite oxidation studies, the pyrite content of the mine
spoil at the experimental site was low. Therefore, a model spoil with a higher pyrite content, derived from Tertiary strata
of the overburden sequence in the same open-cast mine, was used for the column experiments. For the first column experiment,
the model spoil was mixed with fly ash and mineral fertiliser, reflecting the common reclamation practice in the Lusatian
open-cast lignite mining district. Columns with this spoil were either inoculated with different cell numbers of autochthonous
acidophilic bacteria, isolated from the model spoil, or with a commercial strain of Thiobacillus ferrooxidans. The ratio of
sulphate-S to total S was used as a measure for the degree of pyrite oxidation. The ratio of sulphate-S to total S increased
within 28 days of incubation. The increase was related to the inoculated cell numbers of bacteria, but independent of the
origin of the bacteria. It can be stated, that autochthonous bacteria from the model spoil oxidised pyrite at a similar rate
as did the commercial T. ferrooxidans strain. For the second column test, mineral fertiliser, sewage sludge or compost were
applied to the model spoil. The columns were inoculated with autochthonous bacteria, isolated from the model spoil. Application
of sewage sludge and compost seemed to promote the weathering of pyrite, as the ratio of sulphate-S to total S increased more
rapidly in these treatments compared to control or mineral fertiliser application. Both experiments showed an increase of
cell numbers of inoculated bacteria, independent of the ratio of sulphate-S to total S.
This revised version was published online in June 2006 with corrections to the Cover Date.
This revised version was published online in June 2006 with corrections to the Cover Date.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
1