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1.
Kaiwen Pan Zhihong Xu Tim Blumfield Shane Totua Manxin Lu 《Journal of Soils and Sediments》2008,8(6):398-405
Background, aim, and scope Hoop pine (Araucaria cunninghamii) is a nitrogen (N) demanding indigenous Australia softwood species with plantations in Southeast Queensland, Australia. Soil
fertility has declined with increasing rotations and comparison study of N cycling between hoop pine plantations, and adjacent
native forest (NF) is required to develop effective forest management for enhancing sustainable forest production and promoting
environmental benefits. Field in situ mineral 15N transformations in these two forest ecosystems have not been studied. Hence, the present study was to compare the differences
in soil nutrients, N transformations, 15N fluxes, and fate between the hoop pine plantation and the adjacent native forest.
Materials and methods The study sites were in Yarraman State Forest (26°52′ S, 151°51′ E), Southeastern Queensland, Australia. The in situ core
incubation method was used in the field experiments. Mineral N was determined using a LACHAT Quickchem Automated Ion Analyzer.
15N were performed using an isotope ratio mass spectrometer with a Eurovector elemental analyzer. All statistical tests were
carried out by the SPSS 11.0 for Windows statistical software package.
Results Soil total C and N were significantly higher in the NF than in the 53-year-old hoop pine plantation. Concentrations of NO3
– were significantly higher in the NF soil than in the plantation soil. The plantation soil had significantly higher 15N and 13C natural abundances than the NF soil. The NF soil had significantly lower C/N ratios than the plantation soil. NO3
––N was dominated in mineral N pools in both NF and plantation soils, accounting for 91.6% and 70.3% of the total mineral N
pools, respectively. Rates of net nitrification and net N mineralization were, respectively, four and three times higher in
the NF soil than in the plantation soil. The 15NO3
––N and mineral 15N were significantly higher in the NF soil than in the plantation soil. Significant difference in 15NH4
+–N was found in the NF soil before and after the incubation.
Discussion The NF soil had significantly higher NO3
––N, mineral N, total N and C but lower δ15N, δ13C, and C/N ratios than the plantation soil. Moreover, the rates of soil net N mineralization and nitrification were significantly
higher, but ammonification rate was lower in the NF than in the plantation. The NF soil had many more dynamic N transformations
than the plantation soil due to the combination of multiple species and layers and, thus, stimulation of microbial activity
and alteration of C and N pool sizes in favor of the N transformations by soil microbes. The net rate of N and 15N transformation demonstrated differences in N dynamic related to the variation in tree species between the two ecosystems.
Conclusions The change of land use and trees species had significant impacts on soil nutrients and N cycling processes. The plantation
had larger losses of N than the NF. The NO3
––N and 15NO3
––N dominated in the mineral N and 15N pools in both forest ecosystems.
Recommendations and perspectives Native forest soil had strong N dynamic compared with the plantation soil. Composition of multiple tree species with different
ecological niches in the plantation could promote the soil ecosystem sustainability. The 15N isotope dilution technique in the field can be quite useful for studying in situ mineral 15N transformations and fate to further understand actual N dynamics in natural forest soils. 相似文献
2.
A laboratory incubation experiment was conducted to demonstrate that reduced availability of CO2 may be an important factor limiting nitrification. Soil samples amended with wheat straw (0%, 0.1% and 0.2%) and (15NH4)2SO4 (200 mg N kg–1 soil, 2.213 atom% 15N excess) were incubated at 30±2°C for 20 days with or without the arrangement for trapping CO2 resulting from the decomposition of organic matter. Nitrification (as determined by the disappearance of NH4+ and accumulation of NO3–) was found to be highly sensitive to available CO2 decreasing significantly when CO2 was trapped in alkali solution and increasing substantially when the amount of CO2 in the soil atmosphere increased due to the decomposition of added wheat straw. The co-efficient of correlation between NH4+-N and NO3–-N content of soil was highly significant (r =0.99). During incubation, 0.1–78% of the applied NH4+ was recovered as NO3– at different incubation intervals. Amendment of soil with wheat straw significantly increased NH4+ immobilization. From 1.6% to 4.5% of the applied N was unaccounted for and was due to N losses. The results of the study suggest that decreased availability of CO2 will limit the process of nitrification during soil incubations involving trapping of CO2 (in closed vessels) or its removal from the stream of air passing over the incubated soil (in open-ended systems). 相似文献
3.
Svetlana Bykova Pascal Boeckx Irina Kravchenko Valery Galchenko Oswald Van Cleemput 《Biology and Fertility of Soils》2007,43(3):341-348
Methane oxidising activity and community structure of 11, specifically targeted, methanotrophic species have been examined
in an arable soil. Soils were sampled from three different field plots, receiving no fertilisation (C), compost (G) and mineral
fertiliser (M), respectively. Incubation experiments were carried out with and without pre-incubation at elevated CH4 mixing ratios (100 ml CH4 l−1) and with and without ammonium (100 mg N kg−1) pre-incubation. Four months after fertilisation, plots C, G and M did not show significant differences in physicochemical
properties and CH4 oxidising activity. The total number of methanotrophs (determined as the sum the 11 specifically targeted methanotrophs)
in the fresh soils was 17.0×106, 13.7×106 and 15.5×106 cells g−1 for treatment C, G and M, respectively. This corresponded to 0.11 to 0.32% of the total bacterial number. The CH4 oxidising activity increased 105-fold (20–26 mg CH4 g−1 h−1), the total number of methanotrophs doubled (28–76×106 cells g−1) and the methanotrophic diversity markedly increased in treatments with a pre-incubation at elevated CH4 concentrations. In all soils and treatments, type II methanotrophs (62–91%) outnumbered type I methanotrophs (9–38%). Methylocystis and Methylosinus species were always most abundant. After pre-incubation with ammonium, CH4 oxidation was completely inhibited; however, no change in the methanotrophic community structure could be detected. 相似文献
4.
The exchangeable portion of the selectively sorbed 137Cs extractable by a 1 M ammonium acetate solution (α
Ex
) for soils, illite, bentonite, and tripolite was found to increase with the increasing concentration of the competitive cation
M+ (K+ or NH4+) and can be approximated by a logarithmic relationship. For clinoptilolite, the values of α
Ex
did not depend on the concentration of M+. The expression 1 − α
Ex
(C
M=n
)/α
Ex
(C
M
= 16) as a function of the M+ concentration (where α
Ex
(C
M=n
) is the α
Ex
value at the competitive cation concentration equal to 16 mmol/dm3) was proposed to compare the dependence of α
Ex
on the concentration of K+ or NH4+in different sorbents. For soils and illite, these dependences almost coincided, which indicated that the selective sorption
of 137Cs in soils is determined by the presence of illite-group minerals. 相似文献
5.
Zhiqun Huang Zhihong Xu Timothy J. Blumfield Chengrong Chen Ken Bubb 《Journal of Soils and Sediments》2008,8(6):389-397
Background, aim, and scope
Mulching is frequently used to overcome the drought problem in hardwood plantations that are increasingly being established in lower rainfall areas of Queensland, Australia because of increasing land values. In addition to soil water content, soil nitrogen (N) availability is another critical determinant of plantation productivity in these areas. The purpose of this study was to understand how soil mineral N dynamics, in situ N mineralization, and the fate of fertilized N would be affected by mulching during the early establishment of hardwood plantations. 相似文献6.
Alternative silvicultural systems were introduced in Coastal Western Hemlock forests of British Columbia, Canada, to reduce
disturbance incurred by conventional clear-cutting and to maintain the forest influence on soil nutrient cycling. As we hypothesized,
in situ pools and net mineralization of NH4
+ were lower under no and low disturbance (old-growth forest and shelterwood) compared to clear-cuts (high disturbance); in
situ pools and net production of NO3
− were very low across all treatments. Gross transformation rates of NH4
+ increased while those of NO3
− decreased with increasing disturbance, suggesting that these processes were uncoupled. We conclude that shelterwood harvesting
reduces the impact on forest floor NH4
+ cycling compared to clear-cutting, and that neither low nor high disturbance intensity results in substantial NO3
− accumulation, as what occasionally occurs in other ecosystems. We hypothesize that the uncoupling of NH4
+ and NO3
− dynamics may be due to the predominance of heterotrophic nitrification by lignin-degrading fungi that oxidize organic N rather
than NH4
+–N, and whose activities are suppressed at high NH4
+ concentrations. 相似文献
7.
In this study, the effects of 1 h aeration, nitrogen gas N2(g) sparging (15 and 30 min) and increasing ferric ions (Fe+3) as FeSO4 (10, 20 and 50 mg L−1) and Fe3O4 nanoparticles (1, 2 and 4 g L−1) concentrations on three less hydrophobic and three more hydrophobic polycyclic aromatic hydrocarbons (PAHs) and toxicity
removals from a petrochemical industry in Izmir (Turkey) were investigated in a sonicator with a power of 650 W and an ultrasound
frequency of 35 kHz; 1 h aeration increased the yields in benzo[b]fluoranthene, benzo[k]fluoranthene and benzo[a]pyrene PAHs (less hydrophobic) from 62% to 67% to around 95–97% after 150 min sonication at 60°C. However, 1 h aeration did
not contribute to the yields of more hydrophobic PAHs (indeno[1,2,3-cd]pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene). The maximum yields were obtained at acidic and alkaline pH for more and less hydrophobic PAHs, respectively, after
60 and 120 min sonication at 30°C; 30 min N2(g) sparging, 50 mg L−1 Fe+3 increased the yields of less hydropobic PAHs after 150 min sonication at 60°C. Two milligrams per liter of Fe3O4 nanoparticles increased both less (87–88%) and more (96–98%) hydrophobic PAH yields. The Daphnia magna acute toxicity test showed that the toxicity decreased significantly with an hour aeration, 30 min N2(g) sparging, 50 mg L−1 Fe+3 and 2 g L−1 Fe3O4 nanoparticles at 60°C after 120 and 150 min sonications. Vibrio fischeri was found to be more resistant to the sonicated samples than D. magna. Significant correlations were found between the physicochemical properties of sonicated PAHs and acute toxicities both organisms. 相似文献
8.
Hongbo He Huijie Lü Wei Zhang Songmei Hou Xudong Zhang 《Journal of Soils and Sediments》2011,11(5):731-740
Purpose
Amino acids are highly associated with biogeochemical cycling and represent an important potential source and sink of carbon (C) and nitrogen (N) in terrestrial ecosystems. Tracing the isotope dynamics of amino acids can improve the understanding of the origin and transformation of amino acids in soil matrix at process-levels; hence, the liquid chromatographic/mass spectrometric (LC/MS) method to evaluate 13C or 15N enrichment in amino acids is necessary to be established. 相似文献9.
A. I. Scheglov O. B. Tsvetnova E. P. Popova 《Moscow University Soil Science Bulletin》2016,71(2):83-87
Accumulation and distribution of 137Cs by the root systems of forests in the radioactive contamination zone of Bryansk oblast have been discussed. It has been found that the phytomass and distribution of roots of pine and birch trees along the soil profile in the studied BGCs differ considerably. The specific activity of 137Cs in the roots changes depending on their diameter: the lowest specific activity is observed in small fractions of the roots, and the highest one in large fractions. It has been shown that the contribution of roots in the total reserves of 137Cs in the soil layer of 0–50 cm of various biogeocenoses is different: the largest contribution is characteristic for birch forests (1.66%) with variation of this parameter in separate soil layers from 1.12 to 3.53%, while the contribution for pine forests is lower (0.97%) with the variation from 0.82 to 7.5%. The contribution of roots to the overall contamination of soils in the studied plant communities increases with depth. 相似文献
10.
A. Yu. Kudeyarova 《Eurasian Soil Science》2016,49(5):519-528
The participation of anionic aluminum hydroxo complexes in the binding of phosphate anions on the surface of gibbsite has been shown. The succession of changes in the anionic aluminum phosphate complexes under increasing concentration of phosphate solution has been studied. It has been found that aluminum polyphosphate complexes responsible for the intensive dissolution of gibbsite are formed, along with aluminum orthophosphate complexes, at phosphate solution concentrations of 1 and 2 mol P/L. The decisive role of polyphosphate (P–O–P) groups in the ligand structure of anionic complexes in the transformation of gibbsite to a phosphate mineral (ammonium taranakite) has been revealed. The role of hydrogen bonds with the participation of ligand P(O)OH groups in the formation of ammonium taranakite crystals has been discussed. 相似文献
11.
In order to investigate the effect of soil water and texture on C and N mineralisation of applied organic matter, sheep manure was sandwiched between two halves of intact soil cores and incubated at 20°C. The soils contained 10.8% (L1), 22.4% (L3) and 33.7% (L5) clay, respectively, and were drained to seven different matric potentials in the range -15 to -1,500 hPa. Evolution of CO2-C was determined during 4 weeks of incubation. Contents of NO3--N, 15N and microbial biomass N were determined at the end of the incubation. The net release of CO2-C from the manure (estimated as the difference between soils with and without manure) and the total CO2-C evolution from soils with manure was not related to soil water content. Most CO2-C evolved from manure-amended soils in the least clayey L1 soil. The manure caused immobilisation of soil NO3--N but the soil matric potential had no major effects on the net NO3--N production. Less than 1% of the manure 15N was found as NO3--N at the end of the incubation. When unamended, the sandy L1 soil held the least N in microbial biomass but the largest increases in biomass N caused by manure application were found in this soil. Despite the higher increases in microbial biomass N in the L1 soil, the total content of microbial biomass N in soils with manure application peaked in the most clayey soil (L5). The recovery of manure 15N at the end of the incubation ranged from 89% to 102%. The variation in 15N recovery was not related to soil clay content nor to soil matric potential. The experimental set-up was designed to mimic field conditions where manure is left as a discrete layer surrounded by structurally intact soil. In this situation the soil clay content and the soil water level appeared to have little influence on the C and N turnover in the manure layer. 相似文献
12.
Background, aim and scope
This paper discusses a method investigating the reduction of free heavy metal cation contents in soil through the use of microbe-inducing precipitate (MIP). 相似文献13.
The purpose of this greenhouse experiment was to examine the short-term effects of competition between pine seedlings and the soil microbial biomass in sandy oligotrophic pine barrens upland forest soils subjected to varying levels of prescribed fire severity. Pine seedling growth performance, microbial biomass nitrogen, extractable soil nutrients and leaching loss from the soil were determined, throughout a single growing season following fire treatment. Replicate soil cores exposed to three levels of fire severity were maintained in a greenhouse with or without a pine seedling. Throughout the following growing season replicate cores from each treatment were harvested and analyzed monthly. The data allowed testing for two main effects: soil fire treatment and tree presence/absence. In no instance was a significant fire treatment X tree presence/absence interaction found. Our results indicate that biological activity strongly influences soil conditions. Reduced microbial activity resulted from the interaction of soil microbial biomass and an individual pine seedling. Increased plant growth performance correlates with reduced soil mineral nitrogen concentration and decreased pH. At the levels of fire severity utilized in this experiment immobilization due to biological uptake and abiotic soil fixation prevented significant leaching losses above that of unburned control samples. In the oligotrophic, pine barrens soils, nitrogen and phosphorus mineralized by fire are largely conserved by biological processes. These results also suggest that plant growth is subject to limitation by phosphorus availability in these soils. 相似文献
14.
15.
Kwang Seop Kim Man Park Choong Lyeal Choi Dong Hoon Lee Young Jin Seo Chan Yong Kim Jong Su Kim Seok-In Yun Hee-Myong Ro Sridhar Komarneni 《Journal of Soils and Sediments》2011,11(3):416-422
Purpose
A large amount of nitrogen (N) fertilizers has been broadcasted over soil surface for reliable crop production. Unfortunately, the broadcasted N vulnerable to volatilization and leaching can lead to serious environmental problems. As a new approach to mitigate N loss of broadcasted fertilizers, massive intercalation of urea into montmorillonite (MMT) was recently proposed to innovatively enhance the urea use efficiency. This study focuses on demonstrating the behaviors of the urea intercalated into MMT in soils. 相似文献16.
Large amounts of C and N are returned to pasture soils by grazing animals in the form of urine and dung. Therefore, a field
trial was carried out to investigate the mid-term effects of 15N-labeled excrements, produced by feeding a cow with 15N-labeled grass silage, on the soil microbial biomass. Simulating the deposition of excrements, 15N-labeled urine and dung were applied to a 0.09-m2 area of a sandy pasture soil in October 2000 and 2001. Applied amounts
of N were 1,030 and 1,052 kg ha−1, respectively. Soil was sampled at 0–15 cm depth, three times over 7 months and analyzed for total C and N, and microbial
biomass C and N. Recovery of urine and dung N in microbial biomass was determined by 15N analysis of K2SO4 extracts of pre-extracted fumigated and unfumigated soils. Under dung patches, microbial biomass C was 16% and 45% higher,
and microbial biomass N was 24% and 57% higher than under the untreated soil in 2001 and 2002, respectively. Under urine patches,
microbial biomass C was increased after 12 weeks and decreased after 27 weeks. Microbial biomass assimilated 7% to 17% and
10% to 21% of the 15N applied initially as urine and dung, respectively. These percentages were considerably higher than those for artificially
with spiked 15N urea-created and labeled manures reported in previous experiments. An important reason may be that the naturally 15N-labeled N components behave differently in soil than urea spikes. 相似文献
17.
Haiyan Chu Jianguo Zhu Xiangui Lin Rui Yin Zubin Xie Zhihong Cao Takeshi Fujii 《Biology and Fertility of Soils》2007,43(6):811-814
In this study, we investigated the effects of lanthanum (La), one of the rare earth elements (REEs), on microbial biomass
C as well as the decomposition of 14C-labelled glucose in a fluvo-aquic soil in 28 days. The soil was collected from the field plots under maize/wheat rotation
in Fengqiu Ecological Experimental Station of Chinese Academy of Sciences, Henan Province, China. Application of La decreased
soil microbial biomass C during the experimental period, and there was a negative correlation (P < 0.01) between microbial biomass and application rate of La. La increased microbial biomass 14C after 14C glucose addition, and the increase was significant (P < 0.05) at the rates of more than 160 mg kg−1 soil. La slightly increased 14CO2 evolution at lower rates of application but decreased it at higher rates 1 day after 14C glucose addition, while there was no significant effect from days 2 to 28. For the cumulative 14CO2 evolution during the incubation of 28 days, La slightly increased it at the rates of less than 120 mg kg−1 soil, while significantly decreased (P < 0.05) it at the rate of 200 mg kg−1 soil. The results indicated that agricultural use of REEs such as La in soil could decrease the amount of soil microbial
biomass and change the pattern of microbial utilization on glucose C source in a short period. 相似文献
18.
Alberto Agnelli Judith Ascher Giuseppe Corti Maria Teresa Ceccherini Giacomo Pietramellara Paolo Nannipieri 《Biology and Fertility of Soils》2007,44(2):353-361
The aim of this work was to obtain pure extracellular DNA molecules so as to estimate their longevity in soil by an isotope-based
approach. Extracellular DNA molecules were extracted from all horizons of a forest soil and purified by the procedure of Davis
(Purification and precipitation of genomic DNA with phenol–chloroform and ethanol. In: Davis LG, Dibner MD, Battey JF (eds)
Basic methods in molecular biology. Appleton & Lange, Norwalk, 16–22, 1986) without (DNA1) or with (DNA2) a successive treatment with binding resins followed
by elution. The two differently purified DNA samples were compared for their A260/A280 ratio, polymerase chain reaction (PCR) amplification and natural abundance of stable (13C and 15N) and radioactive (14C) isotopes. The purity index and the PCR amplification did not differentiate the efficiency of the two purification procedures.
The isotopic signature of DNA was more sensitive and was strongly affected by the purification procedures. The isotopic measurements
showed that the major contaminant of extracellular DNA1 was the soil organic matter (SOM), even if it is not possible to exclude
that the similar δ
13C, δ
15N and Δ14C values of DNA and SOM could be due to the use of SOM-deriving C and N atoms for the microbial synthesis of DNA. For extracellular
DNA2, extremely low values of Δ14C were obtained, and this was ascribed to the presence of fossil fuel-derived substances used during the purification, although
in amounts not revealed by gas chromatography-mass spectrometry analysis. The fact that it is not possible to obtain contaminant-free
DNA molecules and the potential use of soil native organic compounds during the microbial synthesis of DNA make it not achievable
to estimate the age of soil extracellular DNA by radiocarbon dating. 相似文献
19.
Reducing CH<Subscript>4</Subscript> and CO<Subscript>2</Subscript> emissions from waterlogged paddy soil with biochar 总被引:1,自引:0,他引:1
Yuxue Liu Min Yang Yimin Wu Hailong Wang Yingxu Chen Weixiang Wu 《Journal of Soils and Sediments》2011,11(6):930-939
Purpose
A potential means to diminish increasing levels of CO2 in the atmosphere is the use of pyrolysis to convert biomass into biochar, which stabilizes the carbon (C) that is then applied to soil. Before biochar can be used on a large scale, especially in agricultural soils, its effects on the soil system need to be assessed. This is especially important in rice paddy soils that release large amounts of greenhouse gases to the atmosphere. 相似文献20.
B. F. Aparin E. V. Mingareeva N. I. Sanzharova E. Yu. Sukhacheva 《Eurasian Soil Science》2017,50(12):1395-1405
Data on the concentrations of natural (226Ra, 232Th and 40K) and artificial (137Cs) radionuclides and on the physicochemical properties of chernozems sampled in different years are presented. In 1952, upon the creation of the Penza-Kamensk state shelterbelt, three deep (up to 3 m) soil pits were examined within the former arable field under two-year-old plantations of ash and maple along the transect crossing the territory of the Beloprudskaya Experimental Station of the USSR Academy of Sciences in Volgograd oblast. The samples from these pits were included into the collection of dated soil samples of the Dokuchaev Central Soil Science Museum. Five pits were examined along the same transect in 2009: three pits under shelterbelts (analogues of the pits studied in 1952) and two pits on arable fields between the shelterbelts. In the past 57 years, certain changes took place in the soil structure, bulk density, and the content and composition of humus. The salt profile of soils changed significantly under the forests. The comparison of distribution patterns of natural soil radionuclides in 1952 and 2009 demonstrated their higher contents at the depth of 10–20 cm in 2009 (except for the western shelterbelt). Background concentrations of natural radionuclides in parent materials and relationships between their distributions and the salt profiles of soils have been determined; they are most clearly observed is the soils under shelterbelts. Insignificant contamination with 137Cs (up to 34 Bq/kg) has been found in the samples of 2009 from the upper (0–20 cm) horizon. The activity of 137Cs regularly decreases from the east to the west; the highest concentrations of this radionuclide are found in the topmost 10 cm. This allows us to suppose that 137Cs was brought with aerial dust by eastern winds, and the shelterbelts served as barriers to the wind flow. 相似文献