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1.
安徽省南部第四纪红色粘土的成因 总被引:5,自引:0,他引:5
The particle-size distribution,heavy mineral constituents and rare earth elements(REE) characteristics of the Quaternary red clay of southern Anhui Province were studied to explore the origin of the clay.The results showed that the clay had some properties of areolian deposits,which could be compared with,those of the loess in North China ;and its chondrite-normalized curves of REE were similar to those of the Xiashu loess implying tha they shared the same orighin.It was concluded in combination with the results rported by other researchers that the Quaternary red clay of southern Anhui Province originated from aolian deposts, and this could reveal the cycles of warm and cold climates in the area during the Quaternary period. 相似文献
2.
The soils of the Golan basaltic plateau were surveyed and analyzed. Soils on uneroded plateaus range from montmorillonitic calcareous Reddish Brown Grumusols in the semi-arid areas through noncalcareous Brown Grumusols in the sub-humid areas to Brown and Red Mediterranean Soils with typical argillic horizons and dominance of kaolinitic clay in the humid parts of this region. Protogrumusols and basaltic Lithosols are found in eroded places. Volcanic cone soils in the humid Golan parts range from tuffic Regosols on the youngest cones and most eroded areas through tuffic Red Mediterrranean silty clay loam and silty loam on less eroded areas to tuffic Red Mediterranean clays on the older volcanic eruption sites and comparatively stable slopes.The weathering of the basalt is comparatively very slow, especially in the drier upland areas of the southern Golan. The weathering of the pyroclastic materials, on the other hand is fast, due to the great internal surface of this parent material.The various soils exhibit different leaching stages. A gradual disappearance of lime, decrease in pH values, increase in exchangeable H+ and a shift from montmorillonite clay dominance to kaolinite and similar clay types expresses the increase in the leaching degree from the dry areas to the moist ones.The textural profile of Golan soils depend on clay content and type. A soil sequence commencing with self-mulching Grumusols through various intermediate types to typical ABC Red and Brown Mediterranean Soils may be distinguished along climatic, time and drainage gradients. 相似文献
3.
Land evaluation of basaltic terrain under semi-arid to mediterranean conditions in the Golan Heights
Arieh Singer 《Soil Use and Management》1987,3(4):155-162
Abstract. Soils derived from basalt bordering the northern Jordan Valley have developed under semi-arid to humid Mediterranean conditions and belong to two major soil orders: Vertisols in the drier south and Alfisols (Brown and Red Mediterranean soils) in the more humid north. Major limitations on land use of the vertisols are low hydraulic conductivity, slow infiltration and strong susceptibility to erosion by water. Crops growing on basalt-derived soil also suffer from phosphorus deficiency, though the soils contain much inorganic phosphorus. The natural vegetation is mainly herbaceous and grows well even under intensive and continuous grazing. The land is best used for pasture wherever limitations restrict other uses. 相似文献
4.
第四纪红色粘土发育的红壤中营养元素的淋失 总被引:11,自引:2,他引:11
A red soil derived from Quaternary red clay was employed to study nutrient leaching with soil columns repacked in laboratory. The objective was to identify the effects of fertilization practices on leaching patterns and magnitudes of Ca2+, Mg2+, K+, NH4+, and NO3-. The treatments were CK (as a control), CaCO3, CaSO4, MgCO3, Ca(H2PO4)2, urea, KCl, and multiple (a mixture of the above-mentioned fertilizers). The fertilizers were added to the bare surface of the soil columns, and then the columns were leached with 120 mL deionized water daily through peristaltic pumps over a period of 92 days. Leaching processes of NH4+, and NO3- were only measured in CK, urea, and multiple treatments which were directly related to N leaching. Results showed that sole application of CaSO4, and Ca(H2PO4)2 scarcely had any effect on the leaching losses of Ca2+, Mg2+, and K+; the application of MgCO3 stimulated the leaching of Mg2+; the application of CaCO3 promoted the leaching of Ca2+, Mg2+ and K+; urea treatment also promoted the leaching of K+ and NH4+, and NO3- leaching mainly occurred at late stage of leaching process in particular; under KCl treatment, leaching of Ca2+, Mg2+, and K+ was promoted to a large extent; under multiple treatment, leaching of Ca2+, Mg2+, K+, NH4+, and NO3- was all increased and NO3- was mainly leached at the end of leaching process and still had a trend of increase. 相似文献
5.
污染场地开挖置换后的污染土经过固化处理(S/S法),可作为浅层地基或护岸等非敏感区域的建筑材料,进行污染土的二次利用。针对该项技术,将一定量硝酸锌溶液与风干后红粘土混合,掺入适量水泥,并搅拌均匀、压实成型,标准养护7 d和28 d后依次进行无侧限抗压实验、压汞实验和含水率、体积等指标的测定,研究不同锌离子浓度、水泥掺量和养护龄期对锌污染红粘土水泥固化产物强度、微观孔隙和含水率等的影响。实验结果表明:水泥掺量在10%以内,锌离子浓度小于5000 mg·kg-1,固化物强度随龄期增长而增加;锌离子浓度大于5000 mg·kg-1,强度随龄期增长而先增加后减小。水泥掺量6%和8%时,固化物强度与锌离子浓度呈负相关;而水泥掺量10%时,锌离子浓度对强度的影响存在阈值,且阈值在1000 mg·kg-1附近。与不含锌离子的28 d固化物相比,锌离子浓度小于1000 mg·kg-1时,固化产物孔径小于10 nm的孔隙增加,孔径大于10μm的孔隙减少,强度提高;锌离子浓度在大于1000 mg·kg-1时,严重阻碍C-S-H凝胶物的生成,10μm以上的孔隙和总孔隙率均显著增加,并且生成大量孔径为0.1~10μm的无定型物,同时使红粘土出现亲水性,养护过程中吸收水分且体积增加,强度则大幅度降低。 相似文献
6.
A series of field experiments from 1990 to 1994 in Yingtan, Jiangxi Province, were conducted on an upland red soil derived from Quaternary red clay which had been reclaimed three years before the experiments, in order to study the fertility characteristics and fertilizer requirements of the newly reclaimed soil. The field experiments included that on nutrient characteristics and fertilizer effect, that on K-supplying potential and K-Mg relationship, that on fertilization rates of K and N, etc. The newly reclaimed upland soil was low in both N and P, and its responses to nitrogen and phosphate application were very significant. The K-supplying potential was also low, so the soil was highly responsive to K fertilizer. The effect of Ca and Mg fertilizers was not so great for the reason that certain amounts of Ca and Mg were incorporated into the soil through application of calcium magnesium phosphate during land leveling before the experiments. Among the four micronutrients, B, Mo, Zn and Cu, B had the greatest effect on the soil. The fertilizer requirements of the soil were in an order of P and N > K > lime and B > Mg > Mo, Zn and Cu. Eight crops tested had different fertilizer-requiring characteristics. Rapeseed was very sensitive to P and B fertilizers. Barely was especially sensitive to P and lime and it also responded to B, Mo, Zn and Cu. And sweet potato was especially sensitive to K. 相似文献
7.
Ammonium fixation by clay minerals in different layers of two paddy soils after flooding 总被引:5,自引:0,他引:5
The influence of flooding and cellulose addition on the fixation of NH4
+ in different soil layers of two paddy soils from China (an entisol and an ultisol) was investigated. In both soils the content
of total reducing substances (TRS) sharply increased during the first days after flooding and was highest in the anoxic layers.
This increase, which was more pronounced in the entisol with the higher total C content, was accompanied by an increase in
the concentration of non-exchangeable NH4
+ in both soils. The increase in mineralization after flooding, resulting in higher concentrations of exchangeable NH4
+, favoured the fixation of NH4
+. Although the application of cellulose resulted in higher TRS contents, the fixation of NH4
+ ions decreased, which may have been the result of microbiological N immobilization.
Received: 29 April 1998 相似文献
8.
北京地区红色黏土特性及成土过程和系统分类探讨 总被引:1,自引:1,他引:1
为研究北京地区红色黏土的成土过程及其系统分类,选取6个发育在石灰岩类和花岗岩类母岩上的红色黏土剖面,研究了土壤剖面形态、理化性质、黏土矿物组成等,并分析了其成土条件和发生过程。结果表明:所有土壤剖面的土壤结构体面上均有黏粒胶膜,通体无石灰反应,铁的游离度高,活化度低。石灰岩类发育的红色黏土质地更细,其土壤黏粒游离铁较多,颜色更红,结构体团聚程度更强。花岗岩发育的红色黏土因含有大量难以风化的石英,因而含有较多的砂粒,结构体团聚程度较低。这些土壤形成过程中发生了强烈的黏化和铁质化作用,可以推断其是在古湿热气候条件下形成的。而目前土壤的pH呈微碱或中性,交换性盐基离子以Ca2+为主,盐基饱和度较高,则是受现代黄土降尘的影响,发生了复盐基过程的结果。在此基础上,依据《中国土壤系统分类检索(第三版)》确定的原则和方法,确定研究剖面分属于淋溶土纲下的4个不同亚类。 相似文献
9.
为了明确坡面水流中运移距离对不同层次红壤团聚体自身剥蚀程度的影响,选取3个地区(咸宁、进贤、长沙)典型红壤为研究对象,通过团聚体稳定性分析和室内冲刷水槽试验,就不同层次红壤团聚体稳定性与坡面水流中自身剥蚀程度间定量关系进行了初步探讨。研究结果表明,湿筛法及Le Bissonnais法中的快速湿润、预湿润振荡测得不同层次团聚体稳定性为表层红壤最弱,其次为网纹层,铁锰淀积层最强,而慢速湿润无明显规律,消散作用和机械破碎作用是不同层次红壤团聚体的主要破碎机制;不同层次红壤团聚体在5个运移距离后的剥蚀程度均表现为铁锰淀积层<网纹层<表层;描述团聚体相对机械破碎指数的RMI与5种运移距离后的团聚体剥蚀程度Wr/Wi、剥蚀系数α相关关系显著,利用RMI和运移距离x2个参数建立了坡面水流中不同层次红壤团聚体剥蚀程度预测方程,方程决定系数较高(R2=0.88),显示了较好的预测性能。该结果为研究红壤侵蚀机理提供了参考,对完善土壤侵蚀模型具有一定的参考价值。 相似文献
10.
长江中游地区第四纪红土的二元结构及古环境意义 总被引:3,自引:0,他引:3
在长江中游地区的湖南和湖北两省,选择宜昌、咸宁、常德、长沙、株洲5个第四纪红土剖面,分析第四纪红土的粒度组成特征,研究红土的成因及南方古环境的演变。结果表明,这些地区第四纪红土的粒度组成呈明显的二元结构:剖面上部(宜昌剖面0~320 cm,咸宁剖面0~220 cm,常德剖面0~270 cm,长沙剖面0~280 cm,株洲剖面0~150 cm)粒度细小而均匀,砂粒含量低,大部分小于1%;粗粉砂(又称风尘"基本粒组")相对富集,平均含量分别为34.38%、32.29%、32.48%、31.69%和31.86%。而且土壤样品粒度频率分布曲线与安徽宣城第四纪红土很相似,与镇江下蜀黄土也有明显继承性。这些特性均反映了剖面上层红土的风成特性。但研究剖面下部红土,粒度组成有明显不同:含有砾石,砂粒含量较高,不同粒度组分垂向变化明显,粒度频率分布曲线与宣城红土和下蜀黄土有显著差异,表现出明显的冲、洪积相特性。第四纪红土的"二元结构",反映了研究区域第四纪古环境的多变性和复杂性:早期红土形成后,因受间冰期湿热气候的影响,多受流水作用改造;而晚期红土更多地受风尘堆积的影响,沉积后虽经过了强烈的原位风化,但仍保留了风尘沉积的特性。 相似文献
11.
Two profiles from Muguga, Kenya, one cultivated and one under forest, contained similar contents of clay of apparently uniform composition. The profiles differed in their organic matter contents, surface (0–15 cm) samples containing 6.8% C and 3.8% C in forest and cultivated profiles, respectively. In both profiles the amounts of organic matter decreased with depth.The positive charge, measured at pH 4 in 0.2M NH4 Cl, increased down the cultivated profile to 3.6 me/100 g at 90–120 cm. The charge was lower in the forest profile at equivalent depths, and at 90–120 cm the value was 1.2 me/100 g. Phosphate adsorption measured at pH 5 was also higher in the cultivated profile. The amount of phosphate required to raise the solution concentration to 0.2 p.p.m., ΔP, was 45 and 11 mg/kg in the surface horizon (0–15 cm) of the cultivated and forest profiles, respectively, and increased in both profiles with depth of sample.The differences between, and within, the two profiles are largely attributed to the blocking of positively charged sites and phosphate adsorption sites by organic matter. 相似文献
12.
不同耕种年限红壤性水稻土理化性质的变化特征 总被引:4,自引:2,他引:4
以江西省余江县不同种植年限的红壤性水稻土为对象,研究了土壤有机质、pH、阳离子交换量(CEC)、游离氧化铁含量和氧化铁活化度随时间变化趋势;选择耕种7、22和80年的土壤剖面,研究了游离氧化铁和无定形氧化铁在剖面不同层次的分布。结果表明,耕层(0~20cm)土壤有机质含量随着水稻种植年限的增加而增加,淹水种稻导致土壤pH升高,但主要发生在种稻的前7年,7~80年间土壤pH变化不大。土壤CEC随着种植年限的增加而增加,在17年达到最大,然后随种稻时间的进一步增加而减小。土壤游离氧化铁含量随种稻时间呈下降趋势,但种稻后土壤氧化铁的活化度高于母土旱地红壤。对7年和80年水稻土,表层土壤游离氧化铁的含量低于底层土壤,说明铁在剖面中存在淋溶迁移。7年和22年水稻土表层土壤无定形氧化铁含量高于底层土壤,但对80年水稻土,土壤无定形氧化铁随采样深度的增加而增加。 相似文献
13.
A compilation of some useful approaches used for the obtention of the minimum potential between interacting flat clay double layers is given. Values of the minimum potential obtained from published nomograms, tables and equations are compared. The effect of dissimilar double layers on the potential is also illustrated. 相似文献
14.
为探究红黏土侵蚀劣地植被恢s复的水土保持效益,在自然降雨条件下,对红黏土区裸地对照及植被恢复的2个自然集水区进行长期降雨径流泥沙监测,得到30年的产流产沙数据.结果表明:1)植被恢复第6年裸地对照和恢复林地的产流差距显著,8年后恢复林地基本不再产沙.年内产流产沙集中在雨季4-6月,植被的减流和减沙效益分别超过40%和90%.在次降雨尺度上,植被能够显著降低径流泥沙曲线斜率,在降雨量相同的条件下减小地表产流产沙量.2)降雨过程产流产沙与降雨强度I60变化趋势一致,呈多峰型,总体上恢复区延缓产流1h以上,产流峰值减小67% ~ 83%,中雨条件下植被延缓径流和降低产流峰值的效益最好.3)恢复林地径流中全N、全P、全K流失量分别减少54.62%、57.53%、56.46%,次降雨过程中全N和全K流失质量浓度高于全P浓度,且随径流过程波动较大.植被恢复后的红黏土集水区产流产沙及养分流失显著减少,水土流失得到有效控制. 相似文献
15.
Helena Soinne Riikka Keskinen Mika Tähtikarhu Jukka Kuva Jari Hyväluoma 《European Journal of Soil Science》2023,74(5):e13424
Understanding of factors governing soil structural features is necessary for managing key processes affecting crop productivity and environmental impacts of agriculture, for example, soil water balance, aeration, and root penetration. Organic matter is known to act as a major binding agent in soil aggregation and thus constitutes a central pillar in soil structure formation. However, knowledge of the structural role of organic matter or carbon (OC) in soils highly rich in clay-sized particles (<0.002 mm) is limited. In this study, the effects of clay and OC contents on aggregate stability, water holding capacity, near-saturated hydraulic conductivity, total porosity, and pore size distribution were assessed in cultivated fields with high clay content located in private crop production farms in southern Finland. Significant positive correlations were found between OC content and proportion of water stable aggregates and specific pore sizes from the range of 30 μm up to 1 mm diameter determined by image analysis. Porosities on a smaller size range derived from water retention measurements likewise showed a positive correlation with OC in <0.2 μm sizes. On the range of 0.2–1 μm, a negative relationship was observed, which induced a negative effect of OC on soil plant available water reserves. In line with the positive correlation between OC and larger soil pores, free water, representing the amount of water that can be drained by gravity, exhibited a positive relationship with OC suggesting that OC content can enhance aeration of soils with high clay content. Compared to OC, clay content tended to have an adverse effect on soil structural properties. Clay correlated negatively with pores larger than 30 μm, free water content, and extrapolated field saturated hydraulic conductivity. Further, our imaging results showed how saturated hydraulic conductivity was controlled by pore morphology, and there was a power law relationship between the conductivity and critical pore diameter. in agreement with the percolation theory. Overall, the structural impacts and hydrological implications of OC and clay in heavy clay soils vary by pore size ranges and their emergent practical impacts are thus not straightforward. 相似文献
16.
贺兰山东麓被认为是全球最适宜种植葡萄和生产优质葡萄酒的区域之一。贺兰山东麓葡萄酒产区自北向南已形成石嘴山、银川、永宁、青铜峡和红寺堡等5个产地的区划格局,但因产地风土各异,尚未建立科学规范的葡萄酒产地细分管理方法。为了协助宁夏贺兰山东麓产区强化干红葡萄酒产品区划管理,该研究以贺兰山东麓干红葡萄酒为研究对象,分析葡萄酒色味理化指标的相关性和产地差异性,并依据随机森林的节点权值确定了可反映产地信息的关键色味理化指标。然后,基于近红外光谱和化学计量学方法构建了各项指标的定量分析模型,并以光谱预测结果为输入量,训练了以ReLU为最佳激活函数的人工神经网络产地判别模型,实现了贺兰山东麓干红葡萄酒的产地细分。结果表明,酒石酸酯和pH值的产地差异性最为显著,多项色味理化指标之间存在较强的相关性,通过去低权值指标分析确定了酒石酸酯、多聚体花色苷、pH值、红/绿通道$ {a^*} $、黄/蓝通道$ {b^*} $、总单宁、单体花色苷、明度$ {L^*} $、黄酮醇、滴定酸、离子化指数、乙醇指数、色度$ C_{ab}^* $、总花色苷等14项关键色味理化指标。每项指标的光谱定量模型决定系数(r2)均高于0.90,相对分析误差(RPD)高于2.5,具有准确的定量分析能力;人工神经网络模型对石嘴山酒样判别的灵敏度(sensitivity,SEN)为100%,准确率(accuracy,CCR)为100%;对银川酒样判别的SEN为100%,CCR为90%;对永宁酒样判别的SEN为87.5%,CCR为93.33%;对青铜峡酒样判别的SEN为94.74%,CCR为100%;对红寺堡酒样判别的SEN为92.31%,CCR为92.31%,具有可靠的产地判别能力。该方法可为贺兰山东麓干红葡萄酒的产品区划管理提供技术支撑,有助于中国葡萄酒原产地保护制度的建立与发展。 相似文献
17.
The iron oxide and clay minerals in some typical red and yellow podzolic soils from New South Wales have been investigated by X-ray diffraction and infra-red spectroscopy. The dominant iron oxide mineral is goethite containing about 13–14 mol % AlOOH, this being the mineral which gives the yellow soils their characteristic colour. The red soils also contain finely divided hematite which masks the colour of the goethite. Lepidocrocite was not detected in any of the soils examined. The dominant clay minerals are kaolinite and dioctahedral interstratified illite-smectite, the latter being more concentrated in the finer clay fractions, especially in soils developed on calcareous greywacke. In the red podzolic soil developed on Ashfield shale, illite-smectite is strongly interlayered with well-ordered aluminous material. Dickite occurs in this soil. 相似文献
18.
Kharitonova G. V. Manucharov A. S. Kirichenko A. V. Pavlyukov I. A. 《Eurasian Soil Science》2006,39(1):S69-S77
Quasi-crystals and quasi-crystalline states of matter are a new field of research in solid-state physics. In this respect, the use of highly localized analytic methods making it possible to study the processes on the solid phase surface seems to be very promising. The interaction of soluble salts with clay minerals was studied by electron microscopy. It was found that changes in the hydrosorptive parameters of kaolinite and smectite upon their saturation with soluble salts is related not only to the influence of the residual amounts of salts but also to the transformation of the mineral particles’ structural arrangement and the formation of quasi-crystals. 相似文献
19.
《CATENA》2002,47(1):1-27
In southeastern Australia, aeolian dust deposits are very common and have a significant influence on soil properties and soil landscapes. However, the characteristics of the pure dust materials and the rates of dust-fall in the past are unclear because of the low overall rate of dust deposition and mixing with locally derived sediments. In the Wagga Wagga region, some dunes have functioned as dust traps. Thin (<1 cm thick) red clayey bands and thick (up to 2.5 m) red clayey layers within the dune sequences are likely to represent illuviated aeolian dust. These dust materials are characterised by a bi-modal particle size distribution, one mode in the clay and another in the coarse-medium silt. The clay minerals are dominated by kaolinite, illite and smectite. Both 14C and optical dating indicate the most recent period of dune formation was around 3–4 ka. In an example of these young dunes, there is a total of 2 cm equivalent thickness of dust materials, giving a deposition rate of 0.5–0.7 cm ka−1. All three samples from an elevated dune are saturated with respect to environmental radiation dosage, and give minimum optical ages in excess of 80 ka. In this higher dune, the total thickness of dust is 50–80 cm, similar to that (50–100 cm) of the Yarabee Parna, the youngest aeolian dust deposit in the Wagga Wagga region. This may have been deposited unevenly, being more concentrated during the period 25–16 ka, which has been identified as a major dust deposition period in the Tasman Sea. If this variation occurred, the dust deposition rate indicated by the 50–80 cm dust material in the dune could have been as high as 5 cm ka−1 for the period 25–16 ka. 相似文献
20.
The mineralogy of four Italian Andosols - derived from volcanic material either oversaturated or undersaturated with respect to silica - has been investigated by XRD, EM and IR. The crystalline clay minerals in all four profiles are essentially similar, consisting of abundant halloysite with moderate illite and 14A intergrade material, minor kaolinite and occasional gibbsite. The soils also contain large amounts of imogolite and proto-imogolite allophane. With the exception of illite all these clay minerals are believed to be of pedogenic origin. Halloysite occurs in the dehydrated form in the surface horizons but becomes progressively more hydrated with depth. At depths of > 1.4 m the clay fraction consists almost entirely of fully hydrated halloysite, supporting the suggestion that halloysite forms best in a stagnant moisture regime where there is a depositional overburden acting as a silica source. EM observations show that the halloysite may have spherical morphology and may be intimately associated with gas vesicles in pumice grains where it probably forms by the transformation of allophanic material. It seems likely that dehydrated halloysite slowly converts to poorly crystallized kaolinite in the upper horizons of these profiles. The origin of the 2/1 minerals is more problematical. Illite is probably inherited from mica in the parent material but the 14A intergrade material is so poorly ordered that a pedogenic origin seems more likely than formation by inheritance or by transformation of pre-existing 2/1 silicates. 相似文献