外加碳酸盐增加石灰性土壤密闭培养过程中CO2的释放量

The closed-jar incubation method is widely used to estimate the mineralization of soil organic C. There are two C pools (i.e., organic and inorganic C) in calcareous soil. To evaluate the effect of additional carbonates on CO2 emission from calcareous soil during closed-jar incubation, three incubation experiments were conducted by adding different types (CaCO3 and MgCO3 ) and amounts of carbonate to the soil. The addition of carbonates significantly increased CO2 emission from the soil; the increase ranged from 12.0% in the CaCO3 amended soil to 460% in the MgCO3 amended soil during a 100-d incubation. Cumulative CO2 production at the end of the incubation was three times greater in the MgCO3 amended soil compared to the CaCO3 amended one. The CO2 emission increased with the amount of CaCO3 added to the soil. In contrast, CO2 emission decreased as the amount of MgCO3 added to the soil increased. Our results confirmed that the closed-jar incubation method could lead to an overestimate of organic C mineralization in calcareous soils. Because of its effect on soil pH and the dissolution of carbonates, HgCl2 should not be used to sterilize calcareous soil if the experiment includes the measurement of soil CO2 production.     

福建省变性土的性质、形成和肥力

The zonal soils in the south subtropical zone of Fujian are lateritic red soils.A type of dark clayey soils.which was historically defined as lateritic red soils,derived from weathering products of the basalts was indicated by the investigation results to be markedly different from lateritic red soils and could be classified as Typical Hapluderts.They are distributed as complex zones with the lateritic red soils.The vertisols in this region were considered as a type of lithogenic soils and the vertic characteristics delay and inhibit the soils from allitic processes and then formed an independent soil type.The vertisols have higher fertility and better agricultural production characters than the lateritic red soils.The different ways in utilizing and managing these soils according to their properties and fertility are also suggested.     

中国西南薄层砾石土喀斯特坡地土壤的137Cs分布特点

The fallout radionuclide cesium-137(137 Cs) has been widely employed as a tracer for assessment of soil loss from thick uniform soils;however,few studies have been conducted on thin stony soils on slopes underlain by carbonate rocks which are widely distributed in karst areas.Information derived from 137 Cs measurement of soil samples collected along a carbonate rock slope with thin stony soil where neither soil erosion nor deposition occurred was used to investigate the characteristics of 137 Cs redistribution in a karst area of Southwest China.The results indicated that the 137 Cs inventories of the surface soil on the slope studied were much lower than that of the local 137 Cs reference inventory and the 137 Cs activities were much higher than those on slopes with thick uniform soils.The spatial distribution of 137 Cs inventories was characterized by considerable variation.The high 137 Cs depletion in the stony soil of the slope studied was mainly because a considerable proportion of the fallout input of 137 Cs could be lost with runoff and the dissolution of carbonate particles in the soil promoted the loss of 137 Cs.These demonstrated that the rates of soil loss could not be estimated from the degree of depletion of the 137 Cs inventory relative to the local reference inventory for the thin stony soil of the rocky slope underlain by carbonate rocks in the study area in the way that has been widely used in areas with thick uniform soils.     

小麦分泌的有机酸影响钙质土中锌的释放

Rhizosphere drives plant uptake of sparingly soluble soil zinc(Zn).An investigation with three experiments was conducted to study organic acid exudation by two contrasting wheat genotypes(Sehar-06 and Vatan),Zn fractions in 10 different calcareous soils from Punjab,Pakistan,and release of different soil Zn fractions by organic acids.The two genotypes differed significantly in biomass production and Zn accumulation under deficient and optimum Zn levels in nutrient solution.At a deficient Zn level,Sehar-06 released more maleic acid in the rhizosphere than Vatan.Ten soils used in the present study had very different physicochemical properties;their total Zn and Zn distribution among different fractions varied significantly.Zinc release behaviour was determined by extracting the soils with 0.005 mol L-1 citric acid or maleic acid.The parabolic diffusion model best described Zn release as a function of time.Parabolic diffusion model fitting indicated more maleic acid-driven than citric acid-driven soil Zn mobility from different fractions.Cumulative Zn release in six consecutive extractions during 24 h ranged from 1.85 to 13.58 mg kg-1 using maleic acid and from 0.37 to 11.84 mg kg-1 using citric acid.In the selected calcareous soils,the results of stepwise linear regression indicated significant release of Fe-Mn oxide-bounded soil Zn by maleic acid and its availability to the Zn-effcient genotype.Hence,release of maleic acid by plants roots played an important role in phytoavailability of Zn from calcareous soils.     

中国东北黑土养分空间异质性

Patterns of soil organic carbon (SOC) storage and density in various soil types or locations are the foundation for examining the role of soil in the global carbon cycle. An assessment of SOC storage and density patterns in China based on soil types as defined by Chinese Soil Taxonomy (CST) and the recently compiled digital 11000 000 Soil Database of China was conducted to generate a rigorous database for the future study of SOC storage. First, SOC densities of 7292soil profiles were calculated and linked by soil type to polygons of a digital soil map using geographic information system resulting in a 11000 000 SOC density distribution map of China. Further results showed that soils in China covered 9 281 ×103 km2 with a total SOC storage of 89.14 Gt and a mean SOC density 96.0 t ha-1. Among the 14 CST orders, Cambosols and Argosols constituted high percentage of China's total SOC storage, while Andosols, Vertosols, and Spodsols had a low percentage. As for SOC density, Histosols were the highest, while Primosols were the lowest. Specific patterns of SOC storage of various soil types at the CST suborder, group, and subgroup levels were also described. Results obtained from the study of SOC storage and density of all CST soil types would be not only useful for international comparative research, but also for more accurately estimating and monitoring of changes of SOC storage in China.     

由石灰性冲积物发育而来的排水不良和排水良好的土壤中游离氧化物的分布

A study on the distribution of free iron and manganese oxides was conducted in soils developed on calcareous alluvial deposits under subhumid climatic conditions, in Western Greece. Soil samples from two well drained soils and from two poorly drained soils, classified as Alfisols, were collected and used in this study. After certification of soil homogeneity the acid ammonium oxalate and dithionite-citrate-bicaxbonate methods were used to extract free iron and manganese oxides from the samples. Iron oxides extracted by the dithionite-citrate-bicarbonate method (Fed) were significantly higher than the iron oxides extracted by the ammonium oxalate method (Feo), indicating that a considerable fraction is present in crystalline forms, independent of drainage status. A confirmation of free iron oxides and fine clay was detected. The ratios Feo/Fed and (Fed-Feo)/total Fe (Fet) could not be used to distinguish the well drained soils from the poorly drained soils. Manganese movement in a soluble form is independent of the fine clay.     

外生菌根真菌对土壤无机磷迁移的影响

Ectomycorrhizal(EM) fungi could form symbiosis with plant roots and participate in nutrient absorption; however, many EM species commonly found in forest soils, where phosphorus(P) concentration and availability are usually very low, particularly in tropical and subtropical areas, have not yet been investigated for their efficiencies to mobilize soil P. In this study, fungal growth, P absorption,efflux of protons and organic acids, and soil P depletion by four isolates of EM fungi isolated either from acidic or calcareous soils were compared in pure liquid culture using soil as a sole P source. Boletus sp. 7(Bo 7), Lactarius deliciosus 3(Ld 3), and Pisolithus tinctorius 715(Pt 715) from acidic and P-deficient soils of southwestern China showed higher biomass and P concentration and accumulation than Cenococcum geophilum 4(Cg 4) from a calcareous soil of Inner Mongolia, northern China, after 4 weeks of liquid culture. Oxalate, malate, succinate, acetate, and citrate concentrations in the culture solutions varied significantly with fungal species,and oxalate accounted for 51.5%–91.4% of the total organic acids. Organic acids, particularly oxalate, in the culture solutions may lead to the solubilization of iron-bound P(Fe-P), aluminum-bound P(Al-P), and occluded P(O-P) from soil phosphates. Fungal species also varied greatly in proton efflux, which decreased the culture solution pH and may dissolve calcium-bound P(Ca-P) in soil.This could be the reason for the increment of both inorganic P in the culture solutions and Olsen P in the soil when EM fungi were present. Total inorganic P, the sum of Al-P, Fe-P, O-P, and Ca-P, in the culture solutions was positively correlated with the total concentration of organic acids in the culture solutions(r = 0.918*, n = 5), but negatively with both the total inorganic P in soil(r =-0.970**, n = 5) and the culture solution pH(r =-0.830*, n = 5). These suggested variable efficiencies of EM fungal species to mobilize inorganic P fractions from soil, which could make EM trees to utilize inorganic P in the same way like EM fungi and adapt to the soils with various P concentrations and availabilities.     

综述巴基斯坦农田土壤污水灌溉技术

Raw sewage is widely used on agricultural soils in urban areas of developing countries to meet water shortages. Although it is a good source of plant nutrients, such sewage also increases the heavy metal load to soils, which may impact the food chain. Management options for sewage contaminated soils includes addition of nontoxic compounds such as lime, calcium sulfate and organic matter, which form insoluble metal complexes, thus reducing metal phytoavailability to plants. In this paper we review the variation in irrigation quality of sewage at different sites and its impact on the quality of soils and vegetables. Although quality of sewage was highly variable at source, yet the effluent from food industries was relatively safe for irrigation. In comparison effluent samples collected from textile, dyeing, calendaring, steel industry, hospitals and clinical laboratories, foundries and tanneries were hazardous with respect to soluble salts, sodium adsorption ratio and heavy metals like zinc, copper, iron, manganese, nickel, cobalt and cadmium. The sewage quality in main drains was better than that at the industry outlet, but was still not safe for irrigation. In general, higher accumulation of metals in fruits and vegetable roots was recorded compared to that in plant leaves. Edible parts of vegetables (fruits and/or leaves) accumulated metals more than the permissible limits despite the soils contained ammonium bicarbonate diethylenetriaminepentaacetic acid extractable metals within a safe range. In either case further scientific investigations are needed to ensure safe management strategies. Cadmium appeared to be the most threatening metal especially in leafy vegetables. It is advisable to avoid leafy vegetables cultivation in sewage irrigated areas everywhere to restrict its entry into food chain.     

我国某些土壤中硫素的氧化

The status and activities of boron in soils were studied by the approach of electro-ultrafiltration(EUF).The samples of soils,including brown-red soil and calcareous alluvial soil,were collected from Hubei Province of China.The soil samples were incubated in saturated water and then their nutrients were ultrafiltrated with EUF equipment.Filtration and extraction were conducted in accordance with routine process,but fractions in anode and cathode were all collected.Analyses of B,K^ ,Mg^2 ,Ca^2 ,Cl^- and pH in fractions supposed that boron existed not only in a simple form of borate but also in ion -pair with cations partly in acidic soil,and borate was the primary form existing in the calcareous soil.In studying desorption kinetics with EUF,the boron content of Fractions 2-6 was accumulated.and the accumlative quantities were fit to time factors in three kinetic equations:the zero-order,first-order,and parabolic diffusion equations,Fit degree of the parabolic diffusion equation was the best,followed by the zero-order equation,and the first-order equation was the worst。     

三叶草对污染土壤中芘的去除研究

Phytoremediation has been used as an emerging technology for remediation of soil contamination with polycyclic aromatic hydrocarbons (PAHs), ubiquitous persistent environmental pollutants derived from natural and anthropogenic processes, in the last decade. In this study, a pot experiment was conducted to investigate the potential of phytoremediation of pyrene from spiked soils planted with white clover (Trifolium repens) in the greenhouse with a series of pyrene concentrations ranging from 4.22 to 365.38 mg kg^-1. The results showed that growth of white clover on pyrenecontaminated soils was not affected. The removal of pyrene from the spiked soils planted with white clover was obviously higher than that from the unplanted soils. At the end of the experiment (60 d), the average removal ratio of pyrene in the spiked soils with white clover was 77%, which was 31% and 57% higher than those of the controls with or without micobes, respectively. Both roots and shoots of white clover took up pyrene from the spiked soils and pyrene uptake increased with the soil pyrene concentration. However, the plant-enhanced dissipation of soil pyrene may be the result of plant-promoted microbial degradation and direct uptake and accumulation of pyrene by white clover were only a small part of the pyrene dissipation. Bioconcentration factors of pyrene (BCFs, ratio of pyrene, on a dry weight basis, in the plant to that in the soil) tended to decrease with increase in the residual soil pyrene concentration. Therefore, removal of pyrene in the contaminated soils was feasible using white clove.     

陕西黑垆土在中国土壤系统分类中的归属

在分析陕西省境内9个黑垆土剖面成土环境、剖面形态特征及理化性质的基础上,按照中国土壤系统分类高级及基层分类检索标准,确定了其在中国土壤系统分类中的归属。9个黑垆土剖面的腐殖质层厚度介于30～120 cm,通体均具有强石灰反应,CaCO_3含量介于12.5～189.5 g/kg,其中6个剖面具有30～45 cm的堆垫层。黑垆土共包括淡薄表层、暗沃表层、雏形层、黏化层、钙积层5个诊断层和堆垫现象、钙积现象、盐积现象3个诊断现象,均腐殖质特性、温性土壤温度状况、半干润土壤水分状况以及石灰性4个诊断特性。9个黑垆土剖面在高级分类上可检索为淋溶土和雏形土2种土纲,向下继分为普通钙积干润淋溶土、钙积暗沃干润雏形土、钙积简育干润雏形土以及普通简育干润雏形土4个亚类;其土族鉴别特征可分为黏壤质混合型温性、壤质硅质混合型石灰性温性、壤质混合型温性等6个土族以及胡家庙系、崾崄系、崔木系等9个土系。但目前的系统分类检索结果未能体现黑垆土具有深厚腐殖质层及堆垫现象的典型特性,因此黑垆土的系统分类归属仍需开展深入研究,同时建议新增堆垫干润雏形土土类或堆垫简育干润雏形土亚类,以体现人为农业生产活动对黄土高原地区土壤的影响。     

岷江上游杂谷脑河谷土壤发生特征与系统分类研究

为了解岷江上游杂谷脑河谷的土壤发生特征及类型归属,以位于四川阿坝藏族羌族自治州理县杂谷脑河谷的8个典型土壤剖面为研究对象,通过野外成土因素调查与土壤形态特征观测及室内土壤物理、化学性质分析,依据《中国土壤系统分类检索(第三版)》(简称系统分类)与《中国土壤(1998)》(简称发生分类)鉴定其类型。研究表明,8个剖面均为温性土壤温度状况、半干润土壤水分状况;土壤色调为7.5YR和10YR,部分剖面表层明度和彩度均低于3.5,达到暗沃表层的颜色要求;土壤颗粒组成以粉粒含量最高、砂粒次之、黏粒最低,质地为壤土或粉质壤土;土壤结构主要为亚角块状,部分剖面表层为团粒结构;部分剖面中具有腐殖质、黏粒胶膜及假菌丝体等新生体,形成黏化层和钙积层;均具石灰性,主要为碱性到强碱性反应;有机碳含量范围1.64～61.45 g/kg,部分剖面含量自上而下逐渐降低,具有均腐质特性;游离铁含量为10.78～19.57 g/kg,个别剖面B层均在14 g/kg以上,具有铁质特性;有效磷含量为1.2～43.1 mg/kg,个别符合肥熟表层和磷质耕作淀积层的有效磷含量要求。供试土壤在中国土壤系统分类中归属于人为土、均腐...     

关中地区塿土系统分类归属及代表土系建立

塿土是关中地区受人为长期土粪堆垫而在原土壤表层形成明显堆垫层的重要农业土壤,其分类一直备受关注.为了解塿土的成土特点及系统分类归属,选取关中地区18个典型塿土剖面,通过野外成土因素、剖面形态调查与土样分析测定,依据中国土壤系统分类方案,确定其在高级和基层分类单元归属.结果表明,供试剖面包含堆垫表层、黏化层、钙积层等9个...     

皖南紫红色砂石岩上发育土壤的系统分类研究

对皖南不同时期紫红色砂石岩上发育的8个土壤剖面,按中国土壤系统分类体系,进行鉴别、检索、分类定名。阐述发生分类紫色土的2个亚类级土壤类型在中国土壤系统分类中归为3个土纲,即均腐土、雏形土和新成土;3个亚纲,即湿润均腐土、湿润雏形土和正常新成土;4个土类和6个亚类。提出按中国土壤系统分类的紫色土分类系统;并与美国土壤系统分类、国际土壤分类参比基础进行了参比。讨论了皖南紫红色砂石岩上发育为均腐土的成土环境条件,同时对发生分类紫色土在中国土壤系统分类类别检索提出修订建议。     

湘东第四纪红色黏土发育的典型土壤在中国土壤 系统分类中的归属

选取湖南省东部地区12个由第四纪红色黏土发育的典型土壤剖面,在对其成土环境、剖面形态特征及其理化性质进行研究的基础上,按照中国土壤系统分类方案,检索出了其诊断层和诊断特性,据此确定了其在中国土壤系统分类中的归属。结果表明,供试土壤剖面包含了淡薄表层、暗瘠表层、低活性富铁层、黏化层、聚铁网纹层等10个诊断层和诊断特性,其在中国系统分类体系中的位置分别为:淋溶土、富铁土和雏形土3个土纲;湿润淋溶土、湿润富铁土和湿润雏形土3个亚纲;简育湿润富铁土、铝质湿润淋溶土和铝质湿润雏形土3个土类;暗红简育湿润富铁土、表蚀简育湿润富铁土、网纹简育湿润富铁土等6个亚类;按照土族和土系划分标准,建立了黏质高岭石型酸性热性-普通铝质湿润淋溶土等9个土族和燕塘系(43-LY01)等12个土系。研究发现:受亚热带气候影响,许多土壤剖面发生了富铁铝化过程,且由于淋溶强烈,形成了聚铁网纹层,而现行的《中国土壤系统分类检索(第三版)》还不能给出一个合适的位置,因此建议在铝质湿润淋溶土亚类中增设一个可以反映相关特性的网纹铝质湿润淋溶土亚类。     

重庆市全新统冲积物发育土壤的系统分类研究

为明确重庆市第四系全新统(Qh)冲积物发育土壤在中国土壤系统分类中的归属,本文以该成土母质发育的土壤为研究对象,挖掘9个典型土壤剖面,通过野外观测、分层取样及理化性质分析等,依据现行中国土壤系统分类检索,对其进行分类和命名,并与发生分类进行参比。结果表明:9个供试土壤剖面分别归属于雏形土和新成土2个土纲,5个亚类,其中5个为石灰淡色潮湿雏形土,1个为铁质简育常湿雏形土,1个为斑纹简育湿润雏形土,1个为潜育潮湿冲积新成土,1个为石灰潮湿冲积新成土;隶属于发生学分类潮土土类的6个供试剖面分别归为系统分类中淡色潮湿雏形土、简育常湿雏形土和简育湿润雏形土3个土类,而隶属于发生学分类新积土土类的3个供试剖面则分别归为系统分类中淡色潮湿雏形土和潮湿冲积新成土2个土类。结合成土环境分析可知,地形、气候和母质是影响重庆市第四系全新统冲积物发育土壤系统分类的重要因素。     

基于野外调查信息的河南省灵宝市和襄城县典型烟田的土系建立

以河南省豫中平原区的襄城县和豫西黄土高原区的灵宝市为研究区域,通过对灵宝市5个和襄城县10个典型优质烟田的土壤调查,尝试建立相应的土系。结果表明,灵宝市烟田土壤主要是发育于黄土母质,亚类上均属于普通简育干润雏形土,为同一土族,依据土体中新生体如砂姜、铁锰结核、碳酸钙假菌丝体等的有无可暂划为4个土系。襄城县10个烟田土壤主要发育于黄土冲积物和古黄土性河湖相沉积物上,亚类分别归属于普通钙质干润淋溶土、石灰底绣干润雏形土、变性砂姜潮湿雏形土、石灰淡色潮湿雏形土和普通淡色潮湿雏形土,分属6个土族,同一土族下不同的烟田土壤,主要依据土体色调的差异可暂划为8个土系。     

黄土高原坝淤土发生特性与系统分类研究

[目的]黄土高原区沟坝地经过人工筑坝后自然淤积或者拦蓄洪水淤积而形成坝淤土,为了解坝淤土的发生特性及系统分类归属开展研究.[方法]为本文选取5个典型坝淤土剖面,分析坝淤土的成土环境、剖面形态特征理化性质,检索坝淤土在中国土壤系统分类高级及基层分类的归属.[结果]坝淤土剖面土体深厚,成土母质为人为淤积物质,色调以浊黄橙为...     

安徽宣郎广岗丘区土壤发生分类类型在系统分类中的归属

对宣郎广岗丘地区40个土壤剖面,按中国土壤系统分类体系,进行鉴别、检索、分类定名。阐述土壤发生分类体系的11个亚类级土壤类型在中国土壤系统分类中归为5个土纲,即人为土、富铁土、淋溶土、雏形土和新成土;5个亚纲,即水耕人为土、湿润富铁土、湿润淋溶土、湿润雏形土和正常新成土;15个土类和23个亚类。参比关系复杂,不是简单的一对一的关系。提出按中国土壤系统分类的该区土壤分类系统;并讨论了该区土壤发生分类与系统分类之间具体土壤类型的对应关系。研究结果对土壤类型的正确参比、中国土壤系统分类的应用与发展、具有很好的参考应用价值。     

渝东南岩溶区典型土壤的系统分类研究

为明确渝东南岩溶区典型土壤在中国土壤系统分类中的归属,以该区域石灰岩发育的典型土壤个体为研究对象,挖掘8个典型剖面,通过野外观测、分层取样与分析,依据《中国土壤系统分类检索(第三版)》进行分类检索,并与发生分类进行参比。结果表明,8个供试剖面分别被划归为3个土纲(淋溶土、雏形土和新成土)、5个亚纲、7个土类和7个亚类等系统分类高级单元;在系统分类基层单元归属上,8个剖面分别被划归为8个土族和8个土系。黄棕壤参比到简育常湿雏形土和酸性常湿雏形土,黄壤参比到简育湿润淋溶土,石灰(岩)土参比到钙质常湿(湿润)淋溶土、钙质湿润雏形土和湿润正常新成土。结合成土环境分析可知,在渝东南岩溶区海拔1 000 m的地区,海拔越高,其水分状况越好,越容易形成黏化层;若海拔大致相同,坡度是影响土壤形成黏化层的首要因素;地形和海拔也与渝东南岩溶区的土壤水分状况、雏形层的形成等密切相关,是影响渝东南土壤系统分类归属划分的重要因素。