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1.
The lignite and pyrite containing spoil substrates of the Lusatian mining district are marked by very high acidity and salt
concentrations due to pyrite oxidation and by a very low content of pedogenic organic matter and nutrients. The effects of
fly ash application to neutralize the produced acid and of organic waste material application to improve the ecological soil
functions were studied considering the carbon and nitrogen cycling. Nineteen, 38 and 57 t ha−1 sewage sludge and 22, 44 and 66 t ha−1 compost were applied to ameliorated lignite and pyrite containing substrate. An automated soil microcosm system was used
to analyse the solid, gaseous and liquid phases. Almost 9% of total N applied with sewage sludge (620, 1240 and 1860 t N ha−1 applied) were lost over a period of 150 days mainly as NO3-N. The total N losses from compost treatments were three times lower (2.8–3.1% of applied Nt) and occurred in similar quantities
as NH4-N and NO3-N. Only sewage sludge treatments showed slightly increased N2O emissions at the beginning of the experiment. CO2 emissions determined the carbon losses of all treatments. The C losses amounted to 3.2–4.7% and 1.5–2.7% of Ct applied with sewage sludge and with compost, respectively.
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
2.
Due to a large reclamation (recultivation) demand in the Lusatian lignite mining district, efficient strategies for the rehabilitation
of abandoned mine sites are needed. A field study was conducted for comparing the effects of three different fertilizer treatments
(mineral fertilizer, sewage sludge and compost) on soil solution chemistry of both a lignite and pyrite containing spoil as
well as a lignite and pyrite free spoil. The lignite and pyrite containing spoil was ameliorated with fly ash from a lignite
power plant (17–21 t ha−1 CaO), whereas the lignite and pyrite free site received 7.5 t ha−1 CaO in form of limestone. Fertilizer application rates were: mineral fertilizer 120 N, 100 P and 80 K kg ha−1. 19 t ha−1 sewage sludge and 22 t ha−1 compost were applied. Soil solution was sampled in 20, 60 and 130 cm depth for the period of 16 months. Solution was collected
every fortnight and analysed for pH, EC, Ca2+, Mg2+, K+, Na+, Fen+, Aln+, Mn2+, Zn2+, NO3
−, NH4
+, SO4
2−, Cl−, PO4
3−, Cinorg and DOC. Lignite and pyrite containing spoil differed clearly from lignite and pyrite free spoil regarding soil solution
concentrations and composition. Acidity (H+) produced by pyrite oxidation led to an enhanced weathering of minerals and, therefore, to at least 10 fold higher soil solution
concentrations compared to the lignite and pyrite free site. Major ions in solution of the lignite and pyrite containing site
were Ca2+, Mg2+, Fen+, Aln+ and SO4
2−, whereas soil solution at the lignite and pyrite free site was dominated by Ca2+, Mg2+ and SO4
2−. At both sites application of mineral fertilizer led to an immediate but short term (about 1 month) increase of NO3
−, NH4
+ and K+ concentrations in soil solution down to a depth of 130 cm. Application of sewage sludge caused a long term (about
16 months) increase of NO3
3
− in the topsoil, whereas NO3
− concentrations in the subsoil were significantly lower compared to the mineral fertilizer plot. Compost application resulted
in a strong long-term increase of K+ in soil solution, whereas NO3
− concentrations did not increase. Concentrations of PO4
3− in soil solution depend on solution pH and were not correlated with any treatment.
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.
Organic matter composition and degree of humification in lignite-rich mine soils under a chronosequence of pine 总被引:1,自引:0,他引:1
In the Lusatian mining district, in the eastern part of the Federal Republic of Germany, organic matter of reclaimed mine
soils consists of a mixture of lignite and recently formed soil organic matter (recent carbon). The aim of the study was to
investigate the recent carbon accumulation and the degree of humification of a chronosequence of young mine soils under forest.
The lignite content of the forest floor, Ai (0–5 cm) and Cv horizons (1 m depth) was determined by 14CU activity measurements and the structural composition of the organic matter was characterised by 13C CPMAS NMR spectroscopy. To obtain a characterisation of the degree of humification, the soil samples were analysed for the
content of polysaccharides, proteins, lignin and lipids by wet chemical methods. 14C activity measurements indicate that at the oldest site, comparable amounts of carbon accumulated in the first few centimetres
of the soil profile than in natural forest soils. 13C CPMAS NMR spectra of the organic matter in the Ai horizons of the three soil profiles were dominated by aromatic and alkyl
carbon species characteristic for lignite, but indicated as well an increasing contribution of carbon species from decomposing
plant litter with soil age. When the results from wet chemical analyses were normalised to the total carbon content no changes
with age could be noticed. After normalisation of the amount of litter compounds to the recent carbon content, the carbon
identified by plant litter compound analysis decreased with increasing depth and increasing age of the soils. After 32 years
the values are comparable to those of natural forest soils. These observations were confirmed by increasing degree of lignin
alteration with stand age and soil depth. The data of wet chemical analyses complement data obtained by 14C activity measurements and 13C CPMAS NMR spectroscopy and lead to the conclusion that 32 years after reforestation the degree of humification of the soil
organic matter is in the same range as those of natural sites.
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
4.
Greenhouse experiments were conducted in order to determine for carboniferous and non-carboniferous mine spoil substrates
from the Lusatian lignite mining area (i) the suitable extraction method for plant available P, (ii) the soil capacity for
immobilisation of P and (iii) the impact of sewage sludge and compost on P availability. Ca-lactate extraction (DL) and NH4F-extraction (Bray) were both suited equally well for the determination of plant available P as they extracted similar amounts
of P on both spoils, they showed a close correlation with each other (R=0.97 2) and they showed a close relation with plant P uptake (R2=0.63 and R2=0.66, respectively). Phosphorus recovery from limed carboniferous mine spoil five days after mineral fertiliser application
was only 50%, and decreased to 30% after 54 days. As pH was increased from 3.0 to 5.0 the amount of P immobilised decreased
only by about 5%. Several pH dependent processes of P immobilisation and release could occur concurrently counteracting each
other. One process could be P sorption to newly formed hydroxy-Al-surfaces but P desorption could also take place as pH increases
by decreasing surface positive charge. Finally, due to high Ca concentrations in spoil solution formation of Ca-phosphates,
even at lower pH values, cannot be excluded as a possible mechanism of P immobilisation. As part of the P is bound in organic
matter, application of P with organic matter resulted in a lower P recovery compared to mineral P-fertiliser. However, the
amount of P recovered did not differ between carboniferous and non-carboniferous mine spoil, if P was applied in the form
of organic matter, indicating that the application of P with organic matter might be a measure to overcome P immobilisation
in carboniferous 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
5.
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
6.
On a study site in the Lusatian lignite mining region (Germany), sandy mine spoil was ameliorated with either sewage sludge,
compost or mineral fertilizer. Plots were sown with the grass Secale multicaule and planted with pine seedlings except for
a control that was not meliorated and not revegetated. Pitfall catches of ground beetles in 1996/97 yielded high numbers of
species and individuals directly after revegetation. The dominant beetles were xerophilic species, known to prefer open sandy
sites. Catches in different plots were positively correlated with the amount of vegetation cover and declined as follows:
amelioration with sewage sludge > compost > mineral fertilizer > untreated control. Even beetles characteristic of open sandy
sites showed a distinct preference for plots with high vegetation cover treated with organic waste. For the dominant species,
an attraction to shelter and a more balanced, humid microclimate is assumed. A year-to-year comparison showed an increase
in beetles typical of dry grasslands and ruderal sites in the second year, while characteristic species of open sandy sites
decreased. Application of organic waste combined with revegetation led to an immediate increase in beetle numbers. In the
long term, revegetation would be expected to reduce suitable habitats for endangered ground beetles which prefer open sites
with poor sandy soils.
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
7.
To fulfill the purpose as a sink for trace elements, soils must not be overloaded with As and Cd. Therefore, it is necessary
to get knowledge of the sorption capacities of soils on a regional scale. The determination of these sorption capacities for
large areas is, however, impeded by the great expenditure of laboratory work involved. With data presented here retention
capacities for cadmium and arsenic from routinely determined soil parameters are estimated. In batch experiments the sorption
behaviour of 40 soils from the area of Freiberg/Saxony in Germany was examined. The obtained sorption isotherms from the laboratory
were fitted to the Freundlich equation (S = k*Cm). The two constants (k, m) of this equation were used for multiple linear regression to correlate the sorption capacity and
the soil parameters, namely clay content, pH value, total organic carbon, and dithionite extractable Fe contents. Due to long
lasting ore mining of Freiberg there exist high background levels in that area for the two surveyed elements As and Cd. Therefore,
this study offers two different mathematical procedures to take these contaminations into account. Thus the experimental data
were corrected before they were fitted to Freundlich and pedotransfer equations were determined. Using the transfer equation,
parameter k and m for cadmium sorption could be estimated with statistical certainties of 91% and 61% (adjusted R2), respectively, whereas the predictability for the arsenic sorption is not practicable because achieved R2 values are very low (17% and 7%).
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
8.
The effects of a slow-release N-enriched rock powder on soil chemistry, on the development of the soil vegetation (field layer
vegetation), on the nutritional status of pine seedlings (Pinus sylvestris L.), and on decomposition rates of cellulose in
lignite-poor mine spoils were studied. In the initial phase after afforestation fertilization caused a significant increase
in NO3
−-N concentrations in the soil solution of the top-soil (0–60 cm). Subsequently, NO3
−-N concentrations of all N fertilized treatments decreased with the exception of the highest N application area (500 kg N
ha−1). This decrease of NO3
−-N concentrations was related to the establishment of a field layer vegetation, which developed according to the amount of
N applied. In the above-ground phytomass of the field layer vegetation a maximum N accumulation amount of 22 kg ha−1 was measured. Cellulose decomposition increased with higher N application rates. In the second year after N-fertilization,
the pine needles indicated insufficient supply for almost all nutrients except for N. The deficiency symptoms were most pronounced
at the plots that had received the highest amounts of nitrogen. This phenomenon appears to be related to the competition by
the field layer vegetation.
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
9.
Decomposition of fresh plant residues in soil is expected to produce humic fractions varying in molecular size. It was hypothesized
that metal adsorption by soil, to some degree, will depend on humic acid content and molecular size. The latter is expected
to vary in number and type of functional groups. In this study, illite-humic complexes were used to evaluate Ca2+, Cd2+, and Cu2+ adsorption and how this adsorption was affected by humic acids, differing in molecular size, under various pH values. Potentiometric
titration using ion-selective electrodes with a stop-and-go procedure was employed to evaluate metal-[illite-humic] complex
formation. The results showed that illite-humic complexes exhibited at least two types of metal-ion adsorption sites (low
and high affinity) and molecular size of humic fractions had a large potential influence on total metal adsorption but a relatively
smaller influence on metal-complex stability. Relative strength of metal-ion-[illite-humic] complexes followed the order of
Cu2+>Cd2+>Ca2+ and were affected by pH, especially for low metal-ion affinity sites. Magnitude of metal-[illite-humic] stability constants,
depending on molecular size of humic fraction and pH, varied on a log-scale from 3.52 to 4.21 for Ca2+, 4.38 to 5.18 for Cd2+and from 5.23 to 5.83 for Cu2+. There was an approximate 5-fold difference in these stability constants between the three different sizes of humic fractions.
The larger the humic fraction, the lower the metal-[illite-humic] stability constant.
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
10.
On the basis of long-term field experiments, the impact is demonstrated of the periodic application of organic fertilizers
on the accumulation of organic matter and the development of the micro-pollutant content of reclaimed loess soils of the Rhineland
lignite mining area under agricultural use. The oldest of these experiments (‘Berrenrath Humus Accumulation Experiment’) was
begun in 1969. The results show that the regular input of organic matter (e.g. manure, waste compost, sewage sludge) favors
the accumulation of soil organic matter (SOM). However, the type of organic material applied seems to be less important to
the long-term accumulation process than the application rate. This is also true for composted and uncomposted manure, if the
decay of organic matter during the composting process is taken into account. Nevertheless, the application of similar amounts
of organic C in the form of manure resulted in a higher accumulation of SOM in a nitrogen-reduced farming system. Depending
on the treatment, accumulation rates were between 0.02 and 0.08% SOM per year with values decreasing with time. From these
results, it is estimated that reclaimed soils will take much longer to reach the former SOM level than was previously assumed.
However, it is important to determine which SOM level is adequate for different soil functions (e.g. production function,
filter and buffer function, transformation function), and whether the young SOM of reclaimed soils has the same properties
as older SOM in undisturbed topsoils. As was expected, long-term fertilization with sewage sludge and waste compost led to
an accumulation of some micro-pollutants in the topsoils treated. Nevertheless, the observed concentrations are quite low
compared to background levels in topsoils of rural regions in North Rhine-Westphalia.
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
11.
Soils disturbed by long-term opencast mining were treated with organic waste materials for reclamation. Humic substances were
extracted from waste and soil samples and analysed using pyrolysis-gas chromatography/mass spectrometry and electrofocusing.
Furthermore, analytical pyrolysis permits to study all starting materials in situ. According to structural similarities, the
statistical evaluation of the pyrolysis results clearly indicates three sample groups. The first group, called compost, implies
the waste materials compost and composted sewage sludge. Moreover, pyrolysis revealed that coal humic substances are predominant
in brown coal sludge, pure mine soils and mine soils treated with the different organic waste materials. They constitute the
second group. The sewage sludge contains a high nitrogen potential, as expected, and represents the third group. Finally,
pyrolysis generally showed the specific structural characteristics of humic and fulvic acids, respectively. Electrofocusing
yielded for all samples a signal pattern that is typical of humic substances. However, number and ratio of the signals differ
according to the special structural features of the samples.
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
12.
The individual-based combined forest model EFIMOD including the soil-sub model SOMM has been used for the simulation of Scots
pine stand growth and soil organic matter (SOM) accumulation on a humus-free bare mineral surface. The growth of Scots pine
plantation, with an initial density of 10 000 trees ha−1 and average tree biomass of 0.01 kg was simulated for 50 yr under Central European climatic conditions (i) with varying atmospheric
nitrogen inputs and (ii) different rates of initial application of raw undecomposed organic material or compost, on humus-free
parent material. The accumulation of typical raw humus was simulated in all cases. The accumulation was most intensive in
the simulation of high atmospheric nitrogen input. The humus pool in the mineral topsoil was small but achieved its maximum
value with compost application. SOM nitrogen accumulation was scant in all cases, except the compost applications with low
atmospheric nitrogen input. No statistically significant differences of SOM and stand parameters were found between variants
without organic matter and those with low input of organic manure. However, the maximum relative rate of SOM and nitrogen
accumulation was found in the scenario without organic manure, under slowly growing unstable Scots pine plantation.
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
13.
Experiments in a rewetted fen show large differences in root decomposition rates among Phragmites australis, Carex paniculata,
and Carex riparia. With equal water table fluctuations no differences in decomposition were observed in the two rewetting
variants, with temporary standing and constantly flowing water. The marked differences among species are therefore attributed
to differences in plant material quality, though C/N ratio is shown not to be of main influence. Based on low decomposition
rates, Phragmites australis proved the species most suitable for (renewed) peat accumulation under sufficient wet conditions.
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
14.
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
15.
5-Aminolevulinic acid (10-5 M), a key precursor in chlorophyll biosynthetic pathway, stimulated chlorophyll accumulation in the dark grown black pine
(Pinus nigra Arn.) seedlings and did not affect chlorophyll accumulation in the light.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
16.
Characterization of soil organic matter from a sandy soil in relation to management practice using FT-IR spectroscopy 总被引:1,自引:0,他引:1
Previous results from differently fertilized long-term field experiments on a sandy soil suggested that the chemical composition
of soil organic matter (SOM) is affected by fertilization. The objective of this paper is to confirm this finding for a site
with higher soil-clay contents. Four combinations of different fertilizer treatments at long-term field experiment located
at a sandy loam were selected: liquid manure (LM), liquid manure+N (LM+N), straw+N (S+N) and mineral nitrogen only (N). Soil
organic matter was extracted using sodium pyrophosphate solution at pH of 10 and hot water. The extracts were analyzed using
Fourier-Transform infrared spectroscopy. The results indicate that the composition of SOM from the hot water extracts did
not show significant differences while the sodium pyrophosphate extracted SOM is affected by the type of fertilization. Soil
samples fertilized with LM+N and S+N show the highest intensity of the carboxyl band. This can be explained by the fact that
the combination of S+N fertilization with green manure leads to an enrichment of carboxyl groups in SOM. Differences between
the band intensities of the treatments for the SOM samples are, however, not as distinct as for the sandy soil samples. This
is possibly a result of the higher clay content and lower age of the long-term experiment at the sandy loam site. The intensity
of the carboxyl band of the SOM is correlated with the cation exchange capacity of the soil samples. The composition of SOM
may, in addition to the SOM content, be used for studying quantitative effects of different management practices or even land
use changes on soil properties.
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
17.
Carbon rhizodeposition and root respiration during eight development stages of Lolium perenne were studied on a loamy Gleyic
Cambisol by 14CO2 pulse labelling of shoots in a two compartment chamber under controlled laboratory conditions. Total 14CO2 efflux from the soil (root respiration, microbial respiration of exudates and dead roots) in the first 8 days after 14C pulse labelling decreased during plant development from 14 to 6.5% of the total 14C input. Root respiration accounted for was between 1.5 and 6.5% while microbial respiration of easily available rhizodeposits
and dead root remains were between 2 and 8% of the 14C input. Both respiration processes were found to decline during plant development, but only the decrease in root respiration
was significant. The average contribution of root respiration to total 14CO2 efflux from the soil was approximately 41%. Close correlation was found between cumulative 14CO2 efflux from the soil and the time when maximum 14CO2 efflux occurred (r=0.97). The average total of CO2 Defflux from the soil with Lolium perenne was approximately 21 μg C-CO2 d−1 g−1. It increased slightly during plant development. The contribution of plant roots to total CO2 efflux from the soil, calculated as the remainder from respiration of bare soil, was about 51%. The total 14C content after 8 days in the soil with roots ranged from 8.2 to 27.7% of assimilated carbon. This corresponds to an underground
carbon transfer by Lolium perenne of 6–10 g C m−2 at the beginning of the growth period and 50–65 g C m−2 towards the end of the growth period. The conventional root washing procedure was found to be inadequate for the determination
of total carbon input in the soil because 90% of the young fine roots can be lost.
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
18.
Irrigating arbuscular mycorrhizal plants with leachate from a waste disposal centre was examined in a set of experiments.
Application of leachate at half the average concentration found in the field or higher reduced the growth of the host plant,
the initiation of mycorrhizal colonisation, and hyphal growth of the mycorrhizal fungus Glomus pellucidum through the soil. Causes of these reductions are complex and interrelated, and associated with the electrical conductivity
of the solution, toxicity of specific ions, in particular NH4
+, NH3 and HCO3
−, and changes in the pH causing shifts in the equilibria of the soil solution.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
19.
Application of compost to agricultural soils may be beneficial for crop production by increasing soil fertility and supplying
plant nutrients, however, any raise of the soil organic matter content may increase the potential for unintended groundwater
contamination by nitrate leaching. In this paper, the effect of long-term compost applications on nitrate leaching, soil organic
matter content, and crop production is analyzed using results of simulation scenarios for agricultural sites with loamy and
sandy soils. Simulations were carried out using the Danish Nitrogen Simulation System (DAISY) which describes the nitrogen
balance in a one-dimensional soil-plant-atmosphere system and considers compost type and application rate as well as management
and cropping practice. Estimations of hydraulic and solute transport parameters are based on pedotransfer functions. Data
from a 4.5-year period of field experiments with compost applications in northern Germany as well as from laboratory experiments
with compost amended soil are used for model calibration. Simulation results suggest that: (i) with respect to nitrogen turnover
the differences between compost types (i.e., non-matured and matured) are small compared to site-specific properties (i.e.,
soil temperature and water balance) and management practices (i.e., crop rotation) when considering a compost application
period of 50 years; (ii) with respect to nitrate leaching the effect of different compost application scenarios is highly
sensitive at the sand and relatively small at the loam site; and (iii) relatively high crop yields and acceptably low nitrate
concentrations in the drainage water are obtained at the sand site when applying a combination of 10 t compost/ha/yr and soil-
Nmin adjusted mineral nitrogen additions of about 20 kg/ha/yr to a winter-grain dominated crop rotation. Further optimization
may be possible by applying reduced rates of the (economically interesting) non-matured compost.
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
20.
Emerging buds of rhizome of Alpinia galanga Willd produced shoots and roots simultaneously when cultured in MS medium supplemented
with kinetin 3.0 mg l-1. Each explanted shoot bud produced 8 shoots in average and roots simultaneously within 8 weeks. Shoot proliferation could
be continued even after a year by transferring each divided shoot explant to the same medium. Regenerated plantlets could
be sucessfully transferred to soil where they grew well within 10–12 weeks with 80% survivality.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献