贡嘎山海螺沟冰川退缩区土壤序列矿物组成变化

阐明土壤中矿物随时间变化的机制是理解矿物风化和土壤发育的基础。利用X射线衍射法对贡嘎山海螺沟冰川退缩区土壤矿物组成随成土作用时间变化进行了定量分析。结果表明,冰川退缩区成土母质的矿物组成同质性较高,以硅酸盐矿物为主(约90%),包括:斜长石(28.5%)、石英(24.5%)、黑云母、钾长石、普通辉石、角闪石、绿泥石、蛭石;并有少量碳酸盐矿物,如方解石(8%)、白云石(2.3%);以及磷酸盐矿物磷灰石(2.1%)。退缩区土壤的矿物组成总体呈新发育土壤特征,随着成土年龄的增加,方解石逐渐被风化成为草酸钙石,角闪石、黑云母、磷灰石和绿泥石含量逐渐降低,长英质矿物的相对含量有所增加。成土作用中矿物组成的变化受植被原生演替和土壤p H的影响,快速发育的植被导致土壤p H迅速降低,风化程度增强。     

不同贮藏方法对板栗糖分含量的影响

对不同贮藏方法中板栗糖类物质的变化以及贮藏效果进行了研究.结果表明,板栗不溶性淀粉含量呈逐渐下降趋势,下降速率以室温散装贮藏最快,室温密装最慢;可溶性淀粉和可溶性总糖含量逐渐增加,室温散装增加趋势最明显,而室温密装则先减少然后缓慢增加.不同糖分含量变化结果表明,还原糖含量在砂藏和冷藏过程中逐渐增加,在室温贮藏过程中则缓慢下降,砂藏板栗还原糖含量增加最快、含量最高;果糖和蔗糖含量的变化趋势是缓慢增加,增加最明显的是室温散装板栗,而室温密装板栗呈下降趋势.板栗保鲜效果表明,砂藏、冷藏和室温密装都能起到保水作用,保鲜效果以冷藏最好,砂藏次之,室温密装最差.     

泥炭和褐煤对土壤有机碳和腐殖物质组成的影响

在相同温湿度环境条件下,研究泥炭和褐煤与土壤混合后对土壤有机碳及其腐殖物质组成变化的影响,为改善耕地土壤有机碳库的管理提供理论依据。结果表明:随着培养时间的延长,添加褐煤、木本泥炭的土壤有机碳含量分别上升了0.66%和17.41%,添加草本泥炭的土壤有机碳含量下降了3.15%;胡敏酸含碳量呈逐渐增加的趋势,富里酸含碳量呈逐渐减小的趋势;添加草本泥炭的胡敏素含碳量呈下降趋势,添加褐煤和木本泥炭的土壤胡敏素含碳量呈逐渐上升趋势。土壤胡富比和PQ值整体上都表现出随着培养时间的延长而逐渐增加的趋势。由此可知,泥炭和褐煤能提高土壤有机碳,改良土壤腐殖物质组分,且添加木本泥炭的土壤有机质含量和腐殖物质组分改善效果最好。     

江西低丘红壤性水稻土的主要化学特性研究

三个红壤性水稻土的有机质和腐殖质的含量由淹育型水稻土→潴育型水稻土→潜育型水稻土依次逐渐增加,其C/N和H/P比值也顺次增大。它们的粘土矿物组成无明显差异。铁、锰物质在潴育型水稻土剖面中分异最明显,其次为淹育型水稻土;而无定形氧化铁在剖面中变幅最大却是潜育型水稻土;结晶态铁在土壤剖面中分异亦有一定规律,其中潴育型水稻土的指示性土层(W层)的晶胶率(结晶铁/无定形铁)远较其它土层为高,这种变化特性的差异,对区分不同水分作用的水稻土发育类型有一定的特殊意义;土壤络合态铁与土壤有机质含量有关。土壤氧化锰与土壤氧化铁相比虽然含量低,但对土壤氧化还原条件反应更加敏感,所以在土壤剖面中淋移趋势更加明显。     

基于人工降水入渗的热带海岛表面砂土层水质变化特征

珊瑚砂是热带海岛表层土的重要物质组成,开展大气降水入渗通过表面砂土层的水化学研究是正确认识和评估海岛地下水质的前提.本研究于2017年8月采集了我国热带海岛3种不同样地的典型表层砂土(编号D1、D2和D3),基于人工降雨模拟试验,分析了其基本理化参数变化特征.在此基础上,综合水化学相图、Visual MINTEQ水文地...     

陕北农牧交错带土地荒漠化本质特性研究

通过分析陕北农牧交错带土壤的机械组成、物质成分和理化性质 ,探讨了土地荒漠化的本质。结果表明 :土壤受风沙作用 ,细粒物质逐渐减少 ,表层消失 ,或者被流沙取代 ,原土壤剖面被覆盖在沙层之下 ;土壤质地出现沙化 ,颗粒组成变粗 ;土壤有机质及养分含量减少 ,保水保肥性能降低 ;土壤形成以现代侵蚀和风沙沉积为主 ,物质淋溶和化学风化微弱 ,进化与退化同时共存。     

舟山沿海土壤机油污染的电阻率变化特征及物理影响因素研究

为探索舟山沿海土壤在机油污染情况下电阻率的变化规律及影响因素,通过室内配制污染土,采用单因素分析法研究机油污染砂土、砂质壤土和粉砂质壤土的电阻率变化与土壤质地类型、含水率、含油率及时间的关系。结果表明,土壤构成及含水率与含机油率均对土壤电阻率产生影响。未污染和污染土的电阻率随着含水率的增加呈幂指数下降趋势,其规律符合Archie公式,同时含水率对土壤电阻率的影响大于含油率的影响,并且在一定程度上机油的存在会削弱含水率的影响。5%含水率时,砂质壤土电阻率随含油率增加变化幅度最大,砂土次之,粉砂质壤土最小;15%含水率时,电阻率变化幅度为砂土>砂质壤土>粉砂质壤土。另外,低含水率(5%水)下机油污染粉砂质壤土电阻率随时间的变化波动减小,而高含水率(15%)下则是波动增加,即在经过18~20天后出现小幅下降随后继续增加。根据污染土壤电阻率变化特征可以判断是否存在机油污染,监测效果砂土和砂质壤土优于粉砂质壤土,低含水率条件监测效果优于高含水率条件。研究成果可为土壤机油污染的电阻率法监测提供理论支持。     

水分对崩岗土体抗剪切特性的影响

通过三轴剪切实验研究崩岗不同土层抗剪特性随土壤水分含量变化的规律.结果表明:(1)随着土壤含水量的增加,红土层粘聚力逐步增大,当含水量达到22％后,粘聚力急剧下降;砂土层的粘聚力随含水量的增大而呈现先增大后减小的趋势,但粘聚力变化幅度较小,碎屑层的粘聚力随含水量变化呈波动性变化.(2)3个土层的内摩擦角均随着含水量的增加而减小.(3)3个土层的抗剪强度也随含水量的增加而逐渐减小.     

自动化机械发酵食醋过程中品质变化规律

为全面了解转鼓式反应器固态发酵食醋过程中主要成分和风味物质的动态变化规律,该文对反应器发酵食醋过程进行跟踪取样,利用高效液相色谱、固相微萃取技术、气相色谱-质谱联用技术,对酒精、总酸、还原糖、氨基态氮、有机酸、挥发性风味物质含量变化进行实时监测,结合主成分分析方法,探究食醋不同发酵阶段的风味物质差异。结果表明,酒精含量在发酵0～4 d内迅速增加,随后逐渐下降至零;总酸含量呈现先快速上升后缓慢上升的趋势;还原糖含量呈先快速下降后逐渐上升,最后逐渐下降的趋势;氨基态氮呈现先快速上升后缓慢上升的趋势;乙酸和乳酸是主要的有机酸,整个发酵过程中,乙酸含量持续增加,乳酸含量呈先上升后下降趋势,其他有机酸含量较少,发酵期间变化波动相对较小;共检测出64种挥发性风味物质,包括酯类25种,醇类12种,酸类6种,酚类5种,醛类5种,酮类6种,杂环类5种;发酵前、中、后期的重要挥发性物质分别是醇类化合物、酯类和醛类化合物、酸类化合物。该结果为推进转鼓式固态发酵食醋反应器的实际生产应用提供了理论基础和数据参考。     

水耕年限对黄棕壤发育的水稻土的表面化学性质的影响

利用采自江苏省农业科学院果园的旱地黄棕壤(对照)和由黄棕壤发育水耕20年和60年的水稻土,研究了土壤黏粒和粉粒的矿物组成,胶体和土体的化学性质随水耕年限的变化.粉粒的X-射线衍射图谱表明,3种供试土壤发育母质相似,胶体的矿物组成随水耕年限的变化不大.动电电位和表面负电荷的测定结果也表明,胶体表面化学性质未发生明显变化.随水耕年限增加,土壤黏粒含量降低,导致土体性质发生明显变化,土壤CEC和结构电荷量随水耕年限增加显著减少.     

中国福建省土壤的主要粘土矿物

The clay minerals of more than 200 soil samples collected from various sites of Fujian Province were studied by the X-ray diffraction method and transmission electron microscopy to study their distribution and evolution.Montmorillonite was found in coastal solonchak,paddy soils derived from marine deposit,lacustrine deposit and river deposit,and some lateritic red soil,red soil and yellow soil with a low weathering degree.Chlorite existed mainly in coastal solonchak and paddy soil developed from marine deposit.1.4nm intergradient mineral appeared frequently in yellow soil,red soil and lateritic red soil.The content of 1.4nm intergradient mineral increased with the decrease of weathering degree from lateritic red soil to red soil to yellow soil.Hydrous micas were more in coastal solonchak,paddy soils derived from marine deposit,lacustrine deposit and river deposit.and puple soil from purple shale than in other soils.Kaolinte was the most important clay mineral in the soils iun this province.The higher the soil weathering degree,the more the kaolinite existed.From yellow soil to red soil to lateritic red soil,kaolinite increased gradually,Kaolinite was the predominant clay mineral accompanied by few other minerals in typical lateritic red soil. Tubular halloysite was a widespread clay mineral in soils of Fujian Province with varying quantities.The soil derived from the paent rocks rich in feldspar contained more tubular halloysite.Spheroidal halloysite was found in a red soil and a paddy soil developed from olivine basalt gibbsite in the soils in this district was largely“primary gibbsite” which formed in the early weathering stage.Gibbsite decreased with the increase of weathering degree from yellow soil to red soil to lateritic red soil.Goethite also decreased in the same sequence while hematite increased.     

长期水耕植稻对水稻土耕层质地的影响

为了解长期水耕植稻对南方地区水田表土层颗粒组成的影响,以浙江省为研究区,采用历史资料分析、典型样区调查及定点观察相结合的方法,研究水稻土耕作层(包括犁底层)与心土层间黏粒含量的差异,分析植稻时间对水稻土不同土层颗粒组成的影响,比较植稻期间稻田排水中泥砂物质的颗粒组成与对应土壤间的差异,探讨了长期植稻对水稻土剖面质地分异的影响。对浙江省456个代表性剖面统计,与水稻土心土层比较,耕作层和犁底层黏粒含量平均下降了14%和10%。对植稻不同时间的浅海沉积物(从10～20年至80年)、第四纪红土(从5～20年至70年)和玄武岩风化物(从5～20年至35～70年)发育的水稻土比较发现,随植稻时间的增加,耕作层和犁底层土壤砂粒含量呈现增加趋势,黏粒含量明显下降,耕作层、犁底层与心土层黏粒含量的比值逐渐下降。农田排水中泥砂物质的黏粒和粉砂含量高于对应农田土壤,而砂粒含量则低于相应的土壤。分析认为,长期水耕植稻可导致耕作层土壤砂化(即砂粒含量增加,黏粒含量下降),其原因除与水耕过程中黏粒淋淀外,排水中黏粒和粉砂细颗粒的选择性流失对耕作层砂化也有较大的贡献。     

广西水耕人为土黏粒矿物组成及其空间分布特征

黏粒矿物影响着土壤理化性质,可指示成土因素特征和土壤发生发育过程/强度,也是中国土壤系统分类的基层单元土族矿物学类型划分的重要依据。本研究选择了广西不同纬度和成土母质的18个代表性水耕人为土的剖面,应用X射线衍射(XRD)方法分析了其典型水耕氧化还原层(Br层)的黏粒矿物组成及其空间分布特征,并确定了其中"黏质"剖面的土族控制层段矿物学类型。结果表明:①供试土壤的黏粒矿物主要包括高岭石、伊利石、三水铝石、1.42 nm过渡矿物、蒙脱石和蛭石等,依次分别出现在100%、88.9%、72.2%、61.1%、44.4%和38.9%的剖面中。②黏粒矿物组成在纬度空间分布上具有明显规律性特征。随着纬度降低,土壤黏粒中的高岭石增加,伊利石、蒙脱石、1.42nm过渡矿物逐渐减少;纬度>23°N区域内,成土母质对黏粒矿物组成影响明显。③纬度23°N是黏粒矿物组成和土族矿物学类型分界线,<23°N区域,黏粒矿物均以高岭石为主,是"黏质"剖面的土族控制层段的主要矿物学类型;>23°N区域,黏粒矿物组成以高岭石、蒙脱石、伊利石或1.42 nm过渡矿物为主,因成土母质不同而异,"黏质"剖面的...     

Distribution and development of sclerotium grains as influenced by aluminum status in volcanic ash soils

Granulometric and clay mineralogical analyses were performed on soil types differing in their genesis which had been formed on the raised coral limestone terraces and plateaux under the perhumid subtropical maritime climate of the Ryukyu Islands. The amount of clay fraction in Rendzina-like soil on the lower terrace was relatively small (8-34%) and decreased with depth, while those in Terra fusca-like soils on the middle terraces and in Terra rossa-like soil on the plateau were very large (45–78%) suggesting the occurrence of clay migration.

Rendzina-like soil mainly contained illite and metahalloysite with a moderate amount of mixed layered mineral consisting of illite and vermiculite, and a small amount of vermiculite, Al-vermiculite, goethite, and quartz. Clay mineral composition of Terra fusca-like and Mottled Terra fusca-like soils was similar to that of Rendzina-like soil except that the content of illite was lower in these soils. Terra rossa-like soil, on the other hand, mainly contained Al-vermiculite, metahalloysite, and gibbsite, indicating a highly advanced stage of hydroxyaluminium interlayering. Differences in clay mineral composition from that of Rendzina, Terra fusca, and Terra rossa soils in the European countries were recognized, in that mont-morillonite was absent and hydroxyaluminium interlayering actively proceeded in the soils studied here. This finding is considered to reflect the rapid alteration and intense hydroxyaluminium interlayering of clay minerals under the perhumid subtropical conditions.     

海拔与岩性变异对石灰岩发育土壤黏土矿物组成的影响

用X射线衍射法研究了中亚热带区海拔、岩性变异对石灰岩发育土壤黏土矿物组成的影响。结果表明:在海拔约2 000 m的重庆金佛山山顶区,灰黑色钙质页岩石灰岩发育的黑色石灰土,矿物组成复杂,除伊利石为主外,还有少量蛭石、绿泥石、高岭石和蒙脱石,有一定量的母质残留矿物(滑石和滑间皂石);由砂页岩和灰岩互层母质发育的山地黄棕壤,以蛭石为主,伊利石和高岭石其次,有三水铝石和弱结晶针铁矿。在金佛山中下部(600~1 200 m),石灰岩发育的黄色石灰土以蛭石或伊利石为主,有一定量的高岭石,普遍出现针铁矿。湖南怀化盆地海拔200多米,纯灰岩发育的红色石灰土为伊利石、蛭石和高岭石(含埃洛石)组合型,有结晶好的针铁矿和少量赤铁矿。海拔显著影响高岭石含量、针铁矿结晶度,海拔降低时高岭石含量增加,针铁矿结晶度提高。在金佛山山顶区,石灰岩母质岩性和微地形变异对土壤成土过程和黏土矿物组成影响显著。     

中南地区典型地带性土壤团聚体抗张强度的变化及影响因素

团聚体的力稳性是决定土壤抗侵蚀能力的关键因素。为探究地带性土壤团聚体抗张强度的变化规律及其影响因素,自北向南选取我国中南部地区6种典型地带性土壤(褐土、黄褐土、棕红壤、红壤、赤红壤和砖红壤)的不同粒径(1~2,2~3,3~5,5~10mm)团聚体作为研究对象,通过测定团聚体的抗张强度(TS),探究其与土壤基本理化性质的关系,揭示该区域团聚体抗张强度的变化特点和稳定机制。结果表明:(1)供试土壤皆为黏性土壤,自北向南,随着水热条件的增加,土壤的pH值逐渐降低,高岭石含量和游离氧化物(Fe_d、Al_d)呈现明显的增加趋势;有机质含量随土壤深度的增加而降低。(2)同种土壤团聚体的抗张强度随着粒径的增大而逐步减小,从北至南,相同粒径团聚体的抗张强度整体呈现减小的趋势。(3)TS与pH、粉粒含量、蛭石含量呈极显著正相关(r0.63,p0.01),TS与黏粒含量、1.4nm过渡矿物含量、高岭石含量、游离氧化铁、铝(Fe_d、Al_d)呈显著负相关(r-0.53,p0.05)。(4)逐步回归分析表明,Fe_d和CEC可以较好的预测和评价3~5mm团聚体的抗张强度(R~2=0.80,p0.01)。总体而言,黏土矿物类型及其含量是影响地带性土壤团聚体力稳性的重要因素。研究结果可为该区域土壤侵蚀预测提供一定的理论依据。     

中国东南部某些水稻土的矿物学

Limited information is available concerning the mineralogy of paddy soils in the southeastern China. Using chemical methods in conjunction with X-ray diffractometry, we studied the mineral composition of three paddy soils: Jinghua (paddy soil on Quaternary red clay), Fuyang (Hapl-percogenic loamy paddy soil), and Shaoxing (gleyic clayey paddy soil). All the soils contained quartz, mica, vermiculite, chlorite and kaolinite, and the distribution of these minerals varied with soil particle size fractions. The clay fraction of the Fuyang and Shaoxing soils also contained smectite. Although X-ray data did not show the presence of smectite in the Jinghua soil, this mineral was identified by the chemical method, suggesting a transitional property of the mineral in the soil. Hydroxy-Al interlayered minerals were also present in the clay fraction. The amount of smectite in the soils was 31.6 (Shaoxing), 16.5 (Fuyang), and 21.4 (Jinghua) g kg^-1; for vermiculite it was 33.3 (Shaoxing), 16.5 (Fuyang), and 8.5 (Jinghua) g kg^-1. Smectite was only found in the clay fraction. In contrast, amounts of vermiculite in soil particle size fractions were 3.0~11.4 (sand), 2.1~6.0 (coarse silt), 4.6~18.9 (medium silt), 0.9~40.0 (fine silt), and 17.0~108 (clay) g kg^-1. The amount of noncrystalline aluminosilicates in the soils in g kg^-1 decreased in the order: Shaoxing (2.4) > Jinghua (1.9) > Fuyang (1.7). This study has provided useful mineralogical information that is fundamental in future development of management strategies of the soils.     

山东主要果园土壤的粘土矿物组成及其吸附特性

研究了山东主要果园土壤中粘土矿物的组成、类型及其对P、K和Cu、Zn、Pb金属元素的吸附特性。结果表明：山东主要果园土壤的粘土矿物类型存在着明显的差异,淋溶较强,酸度较大的棕壤（简育湿润淋溶土）中粘土矿物以高岭石占优势,对P的吸附较强,但对K＋吸附固定较弱。含游离C aCO3较高的潮土（淡色潮湿雏形土）和褐土（简育干润淋溶土）,对P有较强的吸附和沉淀作用,使土壤磷的有效性降低。而砂姜黑土（钙积潮湿变性土）由于含有较高的蒙脱石和1.4 nm过渡矿物,对K＋具有很强的吸附和晶穴固定作用,因此砂姜黑土中磷肥和钾肥的有效性均较低,在施肥上应采取集中施肥和保持较湿润土壤环境等措施,以提高养分有效性。砂姜黑土和潮土对Cu、Zn、Pb金属元素的吸附显著地大于棕壤和褐土,主要的影响因素是不同土壤的粘粒含量和粘土矿物的类型的差异。同一土壤对Pb的吸附量远远大于对Zn和Cu的吸附量,主要取决于金属元素本身的化学性质和胶体的吸附特性。     

黄河三角洲不同土地利用类型土壤微观结构特征

黄河三角洲不同土地利用类型盐碱土微观结构的研究,对认识该地区盐碱土的工程性质和对滨海盐碱地治理具有重要意义。该研究结合粒度分析(particle size distribution,PSD)、X射线衍射(X-ray diffraction,XRD)、压汞(mercury intrusion porosimetry,MIP)和扫描电镜(scanning electron microscopy,SEM)方法,对3种不同土地利用类型盐碱土的微观结构进行定量分析,旨在揭示其微观特性,为黄河三角洲盐碱地治理提供微观理论依据。结果表明:不同土地利用类型下的土壤黏粒含量表现大小依次为农田、滩地、草地,而土壤孔隙度大小依次为草地、滩地、农田;农田、草地与滩地盐碱土矿物成分中,石英、方解石和钠长石等原生矿物占绝对优势,仅含少量黏土矿物,且农田黏土矿物含量远大于草地与滩地;草地与滩地盐碱土孔隙特征类似,两者在0.1≤孔隙直径<10μm范围内小孔隙与微孔隙占有绝对优势,而农田盐碱土以孔隙直径在<2μm范围内的微孔隙与超微孔隙为主。农田盐碱土由致密片状、扁平状结构与微裂隙构成,骨架颗粒间由黏土矿物胶结;草地盐碱土由紧密镶嵌的块状颗粒和架空孔隙构成,骨架颗粒间无胶结;滩地盐碱土由紧密堆积的粒状颗粒和粒间孔隙构成,骨架颗粒间无胶结。研究成果可提高对黄河三角洲不同土地利用类型盐碱土微观结构的认识,为滨海盐碱地的治理、利用和开发提供了微观尺度上的依据。     

THE MEASUREMENT AND PREDICTION OF AVAILABLE WATER CAPACITY OF FERRALLITIC SOILS IN UGANDA

Field capacity was measured directly, and soil moisture characteristics were determined on undisturbed cores, for a wide textural range of ferrallitic soils in Uganda. The initial moisture conditions of the soils were shown to affect results and thus standardized procedures were adopted for field and laboratory determinations. Laboratory estimates of field capacity for undisturbed and disturbed samples were shown to be unreliable, but a correction factor was found which improved them. There was no single moisture tension for undisturbed core samples that corresponded to field capacity. Particle-size composition could be related to field capacity, permanent wilting-point, and available water capacity by multiple regression equations having correlation coefficients of 0.96, 0.98, and 0.88 respectively. The relationships predicting available water capacity were different from those found for soils in England, but those for field capacity and permanent wilting-point were similar. Particle-size analyses were carried out using three methods of dispersion of different efficiencies. Particle-size composition following gentle dispersion by shaking soil with distilled water was poorly correlated with moisture-holding properties. There was little advantage in using vigorous ultrasonic dispersion compared with overnight shaking with sodium hexametaphosphate. Two soils formed on alluvial deposits with kaolinite the only clay mineral, and one soil with montmorillonite the dominant clay mineral, showed markedly different relationships between moisture-holding properties and particle-size composition.