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2.
The regularities of the seasonal dynamics of the CO 2 emission from the surface of a podzolic soil under a bilberry pine forest of the middle taiga were revealed. In mid-May, after the snow melt, the CO 2 emission was 0.10–0.20 g of CO 2/m 2 per h. Then, the intensity of the CO 2 emission increased, reached its maximum (1.0 to 1.5 g of CO 2/m 2 per h) in July–August, and decreased down to 0.04–0.10 g of CO 2 g/m 2 per h in mid-October. The correlation between the rate of the CO 2 emission and the temperature and moisture of the soil was positive and negative: r = 0.34 to 0.91 and ?0.44 to ?0.86, respectively. According to the empirical model, 2.26–2.69 t of C-CO 2/ha were emitted during the warm time of the year. 相似文献
3.
Abstract The Ae, Bhf and Bf horizons of two podzolic soils from the Appalachian and Laurentian Highlands were treated with various reagents to remove the amorphous material prior to X‐ray diffraction analysis. Treatments were Na citrate, NaOH, Tiron, DCB and modified DCB, with a lower solid:liquid ratio. Samples treated with NaOH, Tiron and DCB were subsequently extracted with citrate. The latter extraction was necessary to remove Fe 2O 3 and SiO 2 that was not solubilized in the first treatment. The effectiveness of the reagents to extract SiO 2, Al 20 3 and Fe 2O 3 decreased in the following order: DCB 1:1 > Tiron = DCB > citrate > NaOH The total weight loss of the samples represented about 1.8 times the sum of the oxides and reached up to 70% of the Laurentian Bf sample. Organic matter accounted for a part of the weight loss and its removal was more complete in the less crystalline samples of the Laurentian profile. Tiron was the best reagent to improve the X‐ray diffraction patterns, closely followed by DCB 1:1 treatment. Removal of amorphous material and organic matter resulted in a decrease of the cation exchange capacity of the clay fraction, from a maximum of 73.5 meq / 100 g in the Laurentian profile to a minimum of 3.2 meq / 100 g in the Appalachian profile. The results suggested that in the Laurentian profile, very poorly crystallized minerals possibly contributed to a part of the extracted material. 相似文献
4.
The contents of organic compounds in water extracts from organic horizons of loamy soils with different water contents from the medium taiga zone of the Komi Republic were determined by gas-liquid chromatography and chromatography-mass spectrometry. The mass concentration of organic carbon in the extracts was in the range of 290?C330 mg/dm 3; the mass fraction of the carbon from the identified compounds was 0.5?C1.9%. Hydrocarbons made up about 60% of the total identified compounds; acids and their derivatives composed less than 40%. Most of the acids (40?C70%) were aliphatic hydroxy acids. The tendencies in the formation of different classes of organic compounds were revealed depending on the degree of the soil hydromorphism. The acid properties of the water-soluble compounds were studied by pK spectroscopy. Five groups of compounds containing acid groups with similar pK a values were revealed. The compounds containing groups with pK a < 4.0 were predominant. The increase in the surface wetting favored the formation of compounds with pK a 3.2?C4.0 and 7.4?C8.4. 相似文献
5.
In Japan, as the climate is temperate and humid, almost all soils show acid reaction. Especially, a good many strongly acid soils were reported in the survey of reclaimed lands (1, 2). The great majority of strongly acid soils are mineral soils derived from Tertiary or Diluvial sediments. 相似文献
6.
Solution cation concentrations and base cation leaching were simulated for a homogenous soil block and a soil showing five horizons of a podzolic forest soil. The dynamic model ACIDIC simulated water flow, nutrient uptake for tree growth, and cation exchange between H +, Al 3+, Ca 2+, Mg 2+ and K + in forest soil. In the multi-layer simulations exchangeable base cation concentrations changed most in the O horizon. The subsoil had a decisive effect on the pH of the runoff and base cation leaching from the soil. The one-layer model underestimated Ca and Mg leaching and overestimated H + and Al concentrations in the runoff. In the eluvial and the top of illuvial horizon the solution Al / (Ca + Mg) ratio exceeded that in one-layer structure more than 10-fold. Cases with the horizon-specific cation exchange coefficient values and mean coefficient values for all layers showed only minor differences in Al / (Ca + Mg) ratio. The vertical variation in the soil chemical properties should be accounted for even if some details of processes and parameters were unavailable. 相似文献
7.
The origin and nature of halloysite in Ando soils from Towada tephra were investigated. These soils were formed from five tephras: Towada-a (1,000 years old), Towada-b (2,000 years old), Chuseri (4,000 years old), Nanbu (8,600 years old) and Ninokura (10,000 years old).Formation of halloysite took place only in the buried soils from Nanbu and Ninokura tephras occurring in an “accumulating zone”, where thicknesses of overburden tephra deposits were mostly 2.5 m or greater and silica enrichment of the clay fractions could occur.The amounts of halloysite were greater in (1) the soils from Ninokura tephra than in those from Nanbu tephra, and greater in (2) the humus horizons as compared to the nonhumus horizons of these same soils. The mean sizes of spheroidal halloysite particles and the ratios of numbers of tubular to spheroidal forms differed with differences in soil horizons and age.High-resolution electron micrographs of glycerol-solvated spheroidal halloysite particles had lattice images of 11 Å due to (001) from the exterior to the interior and had no indications of layer separation. Moreover, the central core of spheroidal halloysite with a diameter of 150 Å showed neither layer structure nor allophane spherules.Results obtained in this study thus indicate that spheroidal and tubular forms of halloysite were formed concurrently in these Ando soils. 相似文献
8.
Total content of trace elements (Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn), was determined to a depth of about 1 m in the horizons of three representative podzolic soils (i.e., wet moor, dry moor, and dune soil) developed on the coarse sands of the Atlantic face of southwest France. In the aged soils (wet moor and dry moor), Cr, Cu, Ni, Pb and Zn, were highly concentrated in the B horizons whereas Cd accumulated in the litter. An estimate of metal balance was made in the soil profiles, comparing the total amount of metal recovered in the A-B horizons to the amount of indigenous metal determined in a rock matter (C) layer of a similar depth as the A-B horizons. Substantial long-term enrichment of the whole upper part of the profile (A-B horizons) of three representative sites was found for Cd (0.1–0.6 kg ha ?1), Cu (3–12 kg ha ?1), Ni (1–7 kg ha ?1), Pb (20–26 kg ha ?1), and, to a lesser extent, for Co, Mn, and Zn. Since the experimental site was remote from industrial, urban and agricultural activities, the increase in soil metal content was apparently caused by the deposition of metallic aerosols via long-range transport. Total long-term inputs are estimated for average values of Cd (0.6 kg ha ?1), Cr (5 kg ha ?1), Cu (12 kg ha ?1), Ni (7 kg ha ?1), Pb (25 kg ha ?1) and Zn (6 kg ha ?1) for the 1 m depth. Several Atlantic areas of Europe are probably affected by a similar metal input. 相似文献
9.
Samples from the organic horizons of taiga podzolic soils of the Komi Republic were studied, and the possible equilibria established
in the soil-KCl solution system ( c = 1 mol/l) at the determination of the exchangeable acidity by the Sokolov method were examined. It was shown that the exchangeable
acidity was due to aluminum(III) ions in 6% of the samples with pH KCl≤4 and due to the H + ions formed during the dissociation of water-soluble organic acids in the other samples. A group of samples from the horizons
in which Fe 3+ ions could appreciably contribute to the soil acidity was discriminated. 相似文献
10.
This paper deals with characteristics of organo-mineral complexing of microaggregates in the paddy soils developed from purple soils in Sichuan, China. Results show that the contents of organic matter in microaggregates are in the order of 1-0.25 mm > smaller than 0.05 mm > 0.05-0.25 mm. But the organic matter in 1-0.01 mm microaggregates accounts for 68.1%-78.7% of that in soil. The organic matter in < 0.05 mm microaggregates is complexed humus on the whole, of which the degree of organo-mineral complexing varies between 96.1% and 99.5%, which is higher than that of the soil or > 0.05 mm microaggregates. The contents of loosely combined humus and the ratios of loosely and tightly combined humus markedly decline with the size of microaggregates. Flesh soil humus formed from semi-decomposed organic material or organic manure added is combined first with < 0.001 mm clay, and then aggregated with other organic and mineral particles to form larger microaggregates, in which the aging of humus happens at the same time; whereas organic matter of the light fraction is mainly involved in the formation of > 0.05 mm microaggregates. 相似文献
11.
The results of 40 long-term liming experiments in Scots pine and Norway spruce stands on mineral soil sites of varying fertility are reviewed in this paper. Limestone was broadcast at a dose of 2 t ha –1 at the end of the 1950s and sampling was carried out at the end of the 1970s. Liming resulted in considerable accumulation (10 to 50% increase) of organic matter in the humus layer, but no changes in the mineral soil. The C/N ratio of the humus increased on the most productive sites. Liming brought about a long-term decrease in acidity of the humus layer on all site types, as well as a decrease in the mineral soil (0 to 10 cm) of the least productive ones. There was also a corresponding increase in base saturation. There was considerable accumulation of B and Mn in the humus layer. Sulphur was found to have been immobilized to a considerable extent in the humus layer, presumably as Al sulfate. Liming at fairly low doses ( e.g. 2 t ha –1) thus seems to be sufficient to counteract any future increases in soil acidification without bringing about any adverse effects (apart from perhaps B levels) on the nutrient status of the soil. 相似文献
12.
The results of 40 long-term liming experiments in Scots pine and Norway spruce stands on mineral soil sites of varying fertility are reviewed in this paper. Limestone was broadcast at a dose of 2 t ha ?1 at the end of the 1950s and sampling was carried out at the end of the 1970s. Liming resulted in considerable accumulation (10 to 50% increase) of organic matter in the humus layer, but no changes in the mineral soil. The C/N ratio of the humus increased on the most productive sites. Liming brought about a long-term decrease in acidity of the humus layer on all site types, as well as a decrease in the mineral soil (0 to 10 cm) of the least productive ones. There was also a corresponding increase in base saturation. There was considerable accumulation of B and Mn in the humus layer. Sulphur was found to have been immobilized to a considerable extent in the humus layer, presumably as Al sulfate. Liming at fairly low doses ( e.g. 2 t ha ?1) thus seems to be sufficient to counteract any future increases in soil acidification without bringing about any adverse effects (apart from perhaps B levels) on the nutrient status of the soil. 相似文献
13.
The qualitative and quantitative characteristics of the mycobiota in podzolic and bog-podzolic soils were studied in the middle taiga subzone (the Republic of Komi). The complex of micromycetes was found to include 73 species of 18 genera from the Zygomycota and Ascomycota orders and from the formal class of anamorphic fungi. The latter has the following specific features: many forms of sterile mycelium, the predominance of Penicillium species (25), the constant presence of Mucor and Trichoderma species, and single Aspergillus species. With increasing moisture in the sequence of the podzolic, surface-gleyic podzolic, peaty podzolic-gleyic, and peat podzolic-gley soils, the dominant soil fungi are preserved, but the species composition of the micromycete complexes becomes poorer due to the removal of rare species. In the podzolic and bog-podzolic soils, fungi absolutely predominate in the microbial biomass. They accounted for more than 99% of the total biomass, 1–6% of the latter is the biomass of spores, and more than 94% falls on mycelium. In these soils, the reserves of bacterial biomass, as compared to those of fungi, are lower by two orders of magnitude. 相似文献
14.
In samples taken from the AE-horizon of podzolic soil in the rhizosphere of spruce and the area external to it, the general chemical parameters and buffering to acid and base were determined by continuous potentiometric titration. It was found that the rhizosphere soil is characterized by significantly (at P = 0.9) higher general buffering to the base as compared than is that outside the rhizosphere zone due to increased pH values in the range of 9 to 10. This is explained by the large amount of organic matter, and probably mobile compounds of iron and aluminum, in it. During titration by the base, it is assumed that the main buffer reactions in this pH range are deprotonation of phenol hydroxides of specific and nonspecific organic acids, as well as of surface hydroxyl groups of minerals of iron hydroxides, and increase in the basicity of Fe- and Alorganic complexes. 相似文献
15.
A number of field-moist strongly acid soils, NaObr-treated soils, and Al-saturated clays were subjected to drying and wetting treatments in the laboratory. Oven drying of samples resulted in decreases in extractable Al and increases in extractable H from field-moist soils containing more than 12 mequiv./100 g exchange acidity and from Al-saturated clays, and wetting the samples resulted in the reverse. However, when field-moist soil samples containing less than 7 mequiv./100 g exchange acidity were oven dried, both the extractable Al and extractable H tended to increase. Removing organic matter with NaOBr from a soil sample low in exchange acidity resulted in a change from an increase to a decrease in extractable Al upon oven drying. In all cases, the extractable Al and extractable H contents fluctuated cyclically with repeated drying and wetting. The cause for the observed changes was attributed to Al hydrolysis, with additional influence from soil acidity buffering, Al interlayer formation, and inorganic and organic matter dissolution. 相似文献
16.
以长白山、龙岗、宽甸火山喷出物发育土壤为研究对象,对供试土壤形态特征进行描述,并对其pH、有机碳、磷酸盐吸持量、铁铝氧化物、火山玻璃等性质进行测定,按照《中国土壤系统分类检索(第三版)》的原则和方法并结合美国《土壤系统分类检索》第11版,讨论了土壤的诊断层、诊断特性,并进行了分类检索。结果表明:火山喷出物发育的土壤未必就是火山灰土。长白山天池火山锥顶部的土壤发育程度极弱,属于新成土;天池火山锥底部的土壤已经形成土壤结构体,且具有火山灰特性,属于火山灰土;宽甸青椅山顶部土壤以及龙岗金龙顶子底部土壤均具有火山灰特性,检索为火山灰土;宽甸大川头底部土壤0.02 ~ 2 mm粒级含量未达到火山灰特性的要求,但具有雏形层,检索为雏形土。 相似文献
17.
When usual pedological data are combined with detailed biogeochemical and crystallochemical analyses, they indicate existence of two major evolutionary routes within the humid, cool-temperate zone. 1. (a) The first route is the direct result of acidolytic weathering of minerals under the influence of soluble organic compounds which are formed by decomposition of organic matter. This process is thus the result of induced acidification of an extrinsic character, i.e., a podzolization process. 2. (b) The second route is accomplished in a progressive manner according to a true evolutionary sequence. The geochemical mechanisms brought into play are, on the one hand, aluminization of the weathering complex as a result of the hydrolytic desaturation of clays (induced acidification) and, on the other hand, deferrification under hydromorphic conditions, i.e., a degradation process.
The fundamental distinction thus indicated between these two pedological routes serves to answer certain questions relative to genesis and classification of soils of temperate coolzones. 相似文献
18.
Individual argillans in thin sections from a seasonally wet, acid soil were studied by petrographic microscope, X-ray diffraction microcamera, and electron microprobe. The data suggest that, under seasonally reducing and leaching conditions, free iron is reduced and partly leached; smectite and illite are decomposed while at least part of the aluminium, magnesium and potassium liberated is removed by leaching; silica liberated from the smectite and illite is reprecipitated as microcrystalline quartz; and the argillans are residually enriched in rutile and kandite. Birefringent argillans are altered to isotropic, characteristically grainy cutans by this process. Strongly altered parts show a bright opalescent reflection in incident light. 相似文献
19.
The greater part of the middle district of Tottori Prefecture is formed of biotite granite, hornblende andesite, augite andesite and hornblende andesitic volcanic detritus. The granite occurs in the region streching to the north-east from the border between both Tottori and Okayama Prefecture. In this granite area, there can be seen many dikes of aplite and micropegmatite. These granitic rocks, and the soils derived from them have higher radioactivity than other rocks and soils. In this district, there are radioactive hot springs-Sekigane, Misasa, Shikano and Hamamura, and, recently uranium ore was found at Ogamo and Ningyotoge. A study was made on the radioactivity of the soils derived from the granitic rocks, andesite and tertiary shale, of the ashes from plants grown on these soils, and on the extraction of thorium X in the soils. 相似文献
20.
A specific feature of the soil developing near the edge of a sinkhole in comparison with the soil at a distance of 10 m from
the sinkhole is the presence of calcareous horizon from the depth of 116 cm. The soil near the edge of the sinkhole is also
characterized by the increased contents of exchangeable calcium and oxalatesoluble iron in the litter layers and in the AE
horizon. This may be explained by a more active biological uptake of these elements under conditions of a shallow occurrence
of carbonates. With respect to pH values; the contents and distribution of humus and exchangeable potassium, sodium, hydrogen,
and aluminum; the mineralogical composition of the clay and fine silt fractions; and the distribution of oxalatesoluble iron
compounds in the soil profiles, palepodzolic soils of the Central Forest State Biospheric Nature Reserve developing in karst
areas do not differ from similar soils beyond karst areas. 相似文献
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