土壤固化技术应用于戈壁荒漠区水土保持工程的试验研究

依托输变电项目工程,对高强高耐水土壤固化剂(HEC)应用于戈壁荒漠区3种典型土壤的固化效果进行了室内试验研究.试验以无侧限抗压强度要达到1.5 MPa为标准,分别对影响固化效果的养护龄期、固化剂掺量等因素进行了对比分析.结果表明,在养护龄期7d以上,固化剂掺量达到8％以上时,固化剂对3种土壤的固化效果能够达到设计要求.通过对固化样本的力学性能、渗透性能、干缩性能等测试后表明,样本的各项性能均能满足输变电线路工程的水土保持要求.     

EN-1固化剂对4种土壤抗剪强度的影响

[目的]为了探讨离子固化剂路邦EN-1对黄土性土壤的固化性能。[方法]对(土娄)图土、风沙土、黄绵土、黄棕壤4种土在不同固化剂掺量、养护龄期的固化进行了直剪试验。[结果]路邦EN-1固化剂可以有效提高4种土壤的抗剪强度,特别是大幅度提高了(土娄)和黄棕壤的黏聚力。[结论]固化剂的掺量并非越大越好,掺入量过多反而会降低土壤的抗剪强度。掺量为0.01%,养护时间为28d时固化效果最佳。路邦EN-1固化剂适用于黏粒含量较大的土壤,不适用于砂粒含量较大的土壤。     

EN-1固化剂对土壤抗蚀性的影响

在土壤中应用高分子聚合物是改良土壤性质,提高土壤抗蚀能力的主要手段之一。该文以0-30cm和30-100cm土层的塿土和黄绵土为供试土壤,研究了EN-1固化剂的施用对土壤抗蚀性能的影响。利用土壤有机质含量、大于0.25mm的水稳性团聚体含量、水稳性团聚体的平均重量直径(MWD)、几何平均直径(GMD)和分形维数等指标计算土壤抗蚀性,对施用EN-1固化剂后的土壤抗蚀性能进行了定量评价。研究结果表明,EN-1固化剂对土壤抗蚀性的影响程度与固化剂掺量、土壤类型和土壤的取土层次有关,当EN-1固化剂在土壤中的掺量为0.15%(0-100cm塿土和0-30cm黄绵土)或0.20%(30-100cm黄绵土)时,土壤的抗蚀能力最强。试验结果为固化剂在黄土高原水土保持建设中的应用提供了理论指导。     

SSA土壤固化剂对黄土击实、抗剪及渗透特性的影响

为了探讨土壤固化剂对黄土力学特性的影响,通过黄土样中加入SSA土壤固化剂前后的击实试验、直剪试验和渗透试验的对比分析,研究了固化剂掺量、养护龄期与固化土击实、抗剪强度及渗透特性的关系。结果表明,随SSA土壤固化剂掺量增加,固化土的最优含水率有所降低,最大干密度有所增大;固化土的抗剪强度指标黏聚力和内摩擦角随固化剂掺量的增加和养护龄期的延长而增大,渗透系数随固化剂掺量的增加和养护龄期的延长而减小。在实际应用中,建议SSA固化剂最佳掺量为1%,养护龄期至少7 d以上。     

EN-1离子固化剂对黄土性土壤持水、供水等水分特征的影响

为了阐明黄土性固化土壤水分特征的植物有效性,探讨将EN-1固化剂应用于黄土边坡生态防护的可行性。采用室内模拟试验,以黄土地区典型土壤黄绵土为研究对象,对固化土壤的持水、供水、导水及蒸发性能进行研究。结果表明:不同处理土壤水吸力与对应土壤含水量的关系均符合方程θ=aS-b幂函数关系;固化剂降低了土壤的持水能力,但对土壤有效水含量影响不显著。固化剂有利于土壤导水能力提高,固化剂掺量在0.05%~0.10%范围内土壤具有最大入渗能力;无论土壤中是否加入固化剂,随土壤容重增加,土壤饱和导水率降低。固化黄绵土在蒸发初期土壤水分急剧减少,后期趋于缓慢;固化黄绵土累积蒸发量均低于对照,但不同固化剂掺量处理间差异不显著。     

6种固化剂对土壤Pb Cd Cu Zn的固化效果

通过在重金属污染土壤中分别施加沸石、石灰石、硅藻土、羟基磷灰石、膨润土和海泡石6种固化剂,研究了这6种固化剂对土壤中Pb、Cd、Cu、Zn的固化效果,筛选出几种效果较好的固化剂。实验结果表明：沸石、石灰石和羟基磷灰石均能够有效地降低土壤中交换态Pb、Cd的含量,并且明显减少了土壤中Pb、Cd的毒性浸出量,其中沸石最多降低土壤中交换态Pb、Cd含量分别达到48.7%和56.2%,减少土壤中Pb、Cd的毒性浸出量达到37.1%和30.1%;沸石、石灰石均能够有效降低土壤中交换态Cu的含量,降低量分别高达68.1%和85.2%,膨润土能有效减少土壤中Cu的毒性浸出量,减少量最高达到66.51%;石灰石对土壤中Zn有着良好的固化效果。     

土壤固化剂及其水土保持应用研究进展

随着水土流失的加剧和生态环境的恶化,人们不断探索一些水土保持新技术、新材料和新方法,而土壤固化剂作为防治水土流失的一种化学措施应用前景广阔。本文阐述了土壤固化剂的类型特点、固化机理和固化性能,总结了土壤固化剂在水土保持中的应用现状,并指出其应用中存在的若干问题及研究方向,为土壤固化新材料的研发提供指导。     

液态地膜和植生带对土壤水温和玉米成苗的影响

简要介绍了固化剂的特点及工程应用情况,通过击实、无侧限抗压强度、水稳定性和抗冻试验等方 法,探讨了固化剂用于渠道防渗工程的可行性,得出抗冻性能成为土壤固化剂用于渠道防渗工程的制约因 素这一结论,可供同行参考。     

土壤固化剂集流面不同施工工艺比较

土壤固化剂以土壤为固结对象，具有就地取材、减少砂石量和节省工程造价等优点，在集雨工程特别是集流面建设中具有广阔的应用前景。该文在提出固化剂集流面施工工艺分类的基础上，阐述了干硬性－整体施工－固化剂浆液收光、干硬性－整体施工－自然收光、干硬性－砌块施工、塑性－整体施工－自然收光等4种不同施工工艺的技术要求。通过测定集流面的集流效率和粗糙系数，认为固化剂集流面的集流效率达到90％以上，表面粗糙系数在0.011～0.014之间。与混凝土集流面比较，固化剂集流面的建造成本可节约40％以上。试验结果表明：砌块施工工艺在未来固化剂集流面的发展应用中具有重要的地位和价值；单一用途的集流面应考虑塑性施工工艺；表面采用固化剂浆液收光有利于降低集流面的粗糙系数和表面干缩裂缝。     

MBER土壤固化剂集流场的施工工艺

 人工集流场常用的防渗材料有混凝土、聚乙烯薄膜和沥青玻璃丝油毡等,这些材料的集流效率高,但是存在造价高或耐久性差的缺点。应用土壤固化剂修建集流场,能够有效解决集流材料造价高和耐久性差等问题。在阐述MBER土壤固化剂的组成和固化机制、原材料的技术要求、配合比设计和集流场结构设计等基础上,重点研究土壤固化剂集流场的施工工艺,提出了在干硬性施工工艺中混合料的均匀性、含水率和施工时间是应用固化剂修建集流场的关键技术,建议加强对塑性施工工艺的研究。     

Charcoal and smoke extract stimulate the soil microbial community in a highly weathered xanthic Ferralsol

The influence of charcoal and smoke condensates (pyroligneous acid, PA) on microbial activity in a highly weathered Amazonian upland soil was assessed via measurements of basal respiration (BR), substrate-induced respiration (SIR), and exponential population increase after substrate addition. PA extracts are commonly used for fertilizer or as pest control in Brazil, where phosphorus (P) availability and nitrogen (N) leaching are among the most severe limitations for agriculture. Microbes play an important role in nutrient cycling and solubilizing of phosphate. BR, microbial biomass, population growth and the microbe's efficiency (expressed by the metabolic quotient) increased linearly and significantly with increasing charcoal concentrations (50, 100 and 150 g kg⁻¹ soil). Application of PA caused a sharp increase in all parameters. We suppose that the condensates from smoke contain easily degradable substances and only small amounts of inhibitory agents, which could be utilized by the microbes for their metabolism.     

Analysis of cooking oil fumes by ultraviolet spectrometry and gas chromatography-mass spectrometry

This paper investigated the components, especially aldehydes, in the fume condensates from four kinds of cooking oil using ultraviolet (UV) spectrometry and gas chromatography-mass spectrometry (GC-MS). It was observed that there was a great change of the UV absorption spectra from the results of the unheated oil to the results of the fume after heat treatment (190-200, 230-240, and 270-280 degrees C). There was a strong peak within the wavelength range of 260-270 nm in each condensate sample. From the GC-MS results, it was tentatively deduced that there were some 2,4-dialkylenaldehydes and other conjugated compounds in the condensates. The results showed there were large amounts of hexanal and 2-heptenal in the cooking oil fume and that the total aldehyde peak areas of the condensates from four kinds of oil were around 30-50% of the total peak area at 270-280 degrees C.     

Einige chemische Aspekte bei der hydrolytischen Zersetzung von Harnstoff-Formaldehyd-Kondensaten mit Düngewirkung

Some chemical Aspects of hydrolytic Decomposition of Urea-Formaldehyde condensates with fertilizing Effect Model investigations have been made on the hydrolysis of urea-formaldehyde condensates with properties of slowly effective fertilizers. The properties of common urea-form have been compared with those of ureaform preparations enriched with the trace elements cobalt and copper. Data show that with hydrolysis all polycondensates' links are being attacked as depending on the medium pH and amide compounds with shorter chains are being predominantly obtained. Urea is a part of them.     

The challenge for the soil science community to contribute to the implementation of the UN Sustainable Development Goals

Seventeen Sustainable Development Goals (SDGs) were adopted by 193 Governments at the General Assembly of the United Nations in 2015 for achievement by 2030. These SDGs present a roadmap to a sustainable future and a challenge to the science community. To guide activities and check progress, targets and indicators have been and are still being defined. The soil science community has published documents that describe the primary importance of soil for SDGs addressing hunger, water quality, climate mitigation and biodiversity preservation, and secondary relevance of soil for addressing several other SDGs. Soil scientists only marginally participated in the SDG discussions and are currently only peripherally engaged in discussions on targets or indicators. Agreement on several soil‐related indicators has still not been achieved. Involvement of soil scientists in SDG‐based studies is desirable for both developing solutions and increasing the visibility of the soil profession. Inputs into policy decisions should be improved as SDG committee members are appointed by Governments. Possible contributions of soil science in defining indicators for the SDGs are explored in this paper. We advocate the pragmatic use of soil–water–atmosphere–plant simulation models and available soil surveys and soil databases where “representative” soil profiles for mapping units (genetically defined genoforms) are functionally expressed in terms of several phenoforms reflecting effects of different types of soil use and management that strongly affect functionality.     

新疆伊犁新垦区土壤磁化率特征分析

对新疆伊犁新垦区几种不同土地利用方式下土壤磁化率参数及其与土壤有机质、粒度特征关系进行分析,结果表明:不同土地利用方式下土壤剖面的质量磁化率差异明显,杨树林地、农田林带边荒草地、杏林地与农田(几种油葵地)和干旱草场相比,土壤质量磁化率明显偏低;土壤质量磁化率与土壤有机质、粘粒、粉粒含量成负相关,不同土地利用方式相关系数差别较大,与土壤沙粒含量大多呈较好正相关.土壤频率磁化率与有机质、粘粒含量呈现较好正相关,个别达到极显著水平,与土壤粉粒含量呈不明显正相关;与土壤沙粒含量呈较好负相关.     

Application of an algal bioassay to heavy‐metal contaminated soil samples

The aim of this study was to test the effect of heavy‐metal contamination (Cu, Zn) on the growth of Chlorella kessleri. Two soils (Chernozem and Podzoluvisol) were contaminated with several amounts of copper and zinc (100–3000 ppm), and the effects of the soil eluates on the growth of the alga were examined over several days. The soil eluates inhibited algal growth in dependence on metal concentration and soil properties. It was shown that this algal assay, which was first developed for aquatic samples, in principle seems to be suitable also in monitoring soil contamination.     

Submicroscopy of Aggregates of Luvic Phaeozems under Different Land Uses in the Southeast of the Buenos Aires Province,Argentina

Eurasian Soil Science - Soil aggregates are key elements of soil structure that play an important role in several soil processes. One of the major factors that affect soil structure are the...     

Investigating the influence of transgenic tobacco plants codifying a protease inhibitor on soil microbial community

Serine protease inhibitors (PIs) are involved in several physiological processes, such as regulation of endogenous proteinases and defence against phytophageous insects. Transgenic modifications have enhanced protease inhibitor expression to develop insect resistant cultivars in several important crops. The fate of protease inhibitors released from genetically engineered plants is an important issue because of possible inhibition of soil proteases and effects of the insecticidal protein and its codifying sequence on soil microorganisms. The persistence of transgenic sequence mustard trypsin inhibitor-2 in soil and its hypothetical acquisition by soil microorganisms by horizontal gene transfer and the effect of transgenic plant material on soil microbial community structure and soil protease activity were investigated. With the aim to simulate the effects of plant litter on soil microorganisms, a microcosm experimental model was used. Despite the persistence of transgenic DNA sequences, no recombination event was detected between plant DNA and soil bacteria; molecular analysis of bacterial community also showed no significant influence on the dominant members of the bacterial community and soil protease activity was not inhibited by the release of constitutively over-expressed protease inhibitor.     

应用同位素示踪土壤侵蚀研究的进展

 介绍不同类型的同位素的来源,对几种常用的同位素示踪土壤侵蚀的应用做了比较详细的总结。在过去几十年里,人为放射性核素137Cs在土壤侵蚀示踪研究中应用最广泛。同位素210Pb来自于自然界,它在土壤侵蚀中应用的准确度,有待于进一步探讨。宇宙射线产生的放射性核素中,主要介绍7Be在土壤侵蚀研究中的应用。对稳定性稀土元素和几种核素复合示踪土壤侵蚀与泥沙来源研究的国内外研究进展,进行了总结和评价。对应用同位素示踪土壤侵蚀的发展方向,提出了一些看法。     

裸露地表土壤水分的L波段被动微波最佳角度反演算法

该文阐述了中纬度地区春季裸露耕地土壤水分监测的重要性,对比分析了目前几种主要的土壤水分反演方法。为提高裸露耕地土壤水分的监测精度,在分析AIEM土壤发射率模拟数据库的基础上,提出了一种基于L波段单角度双极化被动微波遥感数据的土壤湿度和土壤粗糙度的反演算法,并对新反演算法的创新性和可行性进行了基于仿真数据的论证。该反演算法以地表温度作为辅助数据,利用L波段47°双极化的微波亮温数据进行土壤湿度和粗糙度的反演。仿真数据的验证结果表明,在充分考虑土壤温度、土壤质地等辅助数据测量误差的条件下,算法对土壤湿度和土壤