Evaluation on Soil Heavy Metal Pollution of Agricultural Habitat Environment in Xi'an City

[Objective] This study aimed to understand and grasp the soil heavy metal pollution status of agricultural habitat environment in Xi＇an City. [Method] The soil heavy metal pollution status of pollution-free agricultural products-producing areas in 9 counties （districts） of Xi＇an City was investigated. A total of 609 soil samples were collected, and their Cd, Hg, As, Pb and Cr contents were determined. In addition, the heavy metal pollution status of the collected soil samples was evaluated by Nemerow index method. [Result] The pollution in Baqiao, Chang＇an; Gaoling, Lan- tian, Lintong and Yanliang was of grade I, belonging to clean level; the pollution in Hu County, Weiyang and Zhouzhi was of grade II, near the warning line, belong to relatively clean level. There was no large-area soil heavy metal pollution overall. The investigated areas could be used as production bases of pollution-free agricultural products and even high-quality agricultural products. However, the heavy met- als contents in some individual areas exceeded relevant soil environmental quality standards, and they should be avoided or forbidden during regional planning and selection of production area. [Conclusion] Soil heavy metal pollution of agricultural habitat environment in Xi＇an City is generally at good status. Targeting at the future development plan of Xi＇an City, feasible and scientific suggestions are put forward.

Soil Heavy Metal Pollution Evaluation around Mine Area with Traditional and Ecological Assessment Methods

As a widespread problem, heavy metals contamination in soil has drawn considerable study interest, especially for the farmlands around mine area. A variety of pollution evaluation methods have been compared including both traditional physical and chemical analysis methods as well as ecological assessment methods. And the combination of multiple assessment methods was recommended to get a comprehensive and through soil heavy metal pollution evaluation.

A Study on Rice Growth and Soil Environments in Paddy Fields Using Different Organic and Chemical Fertilizers

Currently, the majority of paddy fields in Japan are grown using chemical fertilizers and synthetic chemical pesticides, since chemical fertilizers can provide the nutrients necessary for plant growth. However, there are concerns regarding the environmental impact of chemical fertilizer and pesticides production, such as reduction of soil microorganisms and water pollution due to the runoff of fertilizer components from the soil caused by excessive fertilizer application. In this study, we investigated the effects of the application of organic and chemical fertilizers on the plant growth of paddy fields, in addition to their effects on the chemical and biological properties of the soil. The panicle numbers of rough and brown rice, the 1000-grain weight of the rough and brown rice, and the percentages of ripened grains were significantly higher in paddy soils grown with organic fertilizers than in those grown with chemical fertilizers. In addition, the total carbon (TC) contents and pH values were significantly higher in the soils of paddy fields grown with organic fertilizers. Furthermore, the soils of paddy fields grown with organic fertilizers exhibited greater bacterial biomasses, N circulation activity, and P circulation activity than the soils of paddy fields grown using chemical fertilizers, although the differences were not significant. In this study, the difference in plant growth was appeared in fertilizer application such as organic and chemical fertilizers. It was indicated that the organic fertilizer and pesticide reduction management increased the soil bacterial biomass and activated the material cycle such as N circulation activity.

天山北坡雪岭云杉森林土壤微生物群落及影响因素研究

土壤微生物是维持森林生态系统平衡与土壤养分的一个重要因素。雪岭云杉林是天山重要的生态屏障和珍贵生物资源,其生态系统的固碳能力持续提升。研究雪岭云杉森林土壤微生物群落特征及微生物与土壤养分之间的互作关系,对维持雪岭云杉森林生态系统质量,促进雪岭云杉森林生态系统可持续发展至关重要。以天山北坡雪岭云杉林表层土为研究对象,利用宏基因组技术,探究天山北坡雪岭云杉林土壤微生物群落组成和多样性及其影响因素。结果表明,天山北坡雪岭云杉林土壤微生物群落特征表现为细菌相对丰度82.5%,真菌1.3%,古菌0.5%,其他15.7%。细菌Alpha多样性在中东部和西部之间有显著性差异;古菌Beta多样性在中部与西部存在显著差异,且中部和东部之间极显著;细菌Beta多样性在3个区域之间均有显著差异,其中西部与东部极显著;真菌Beta多样性仅中部与东部存在极显著差异。古菌多样性主要受有机碳、总氮、pH和土壤湿度的影响;细菌多样性主要受氮素、pH、年均降水量和年均摄氏温度的影响;真菌群落多样性主要受微生物碳和年均摄氏温度的影响。综上说明,土壤因素和水热条件在天山北坡雪岭云杉林土壤微生物群落分布中起主要控制作用,其中pH值和年均摄氏温度是微生物类群空间分异的主导因素。该研究探讨了环境因子对雪岭云杉林土壤微生物分布的调控作用,为今后森林的经营和可持续发展提供依据。

考虑微生物要素的土壤质量综合评价——以北京市平谷区为例

为探讨北京市平谷区土壤质量现状,本研究在传统的土壤质量综合评价体系基础上考虑了微生物要素,基于实地网格土壤采样的228个样本,从土壤肥力、土壤环境、土壤微生物3个维度选取11项土壤指标,采用土壤质量指数法定量分析各指标并计算土壤质量指数,综合评价北京市平谷区的土壤质量。结果表明:平谷区土壤质量综合指数(ISQI)在良好到优等范围内(0.60~0.96),平均值为0.74,平均土壤质量综合评价等级为良好。空间分布上整体呈现南低北高、西低东高的特征,北部熊儿寨乡、黄松峪乡及东部金梅湖镇等地区多为山地或林地,植被丰富,人为活动强度弱,土壤肥力水平高且微生物较为丰富,土壤质量综合评价等级相对较高;而西南部马坊镇、马昌营镇等地区土壤肥力水平低,微生物数量较少,综合质量评价等级相对较低。熊儿寨乡的ISQI最高,为0.81;平谷镇的ISQI最低,为0.64。平谷区不同土地利用类型ISQI排序为果园>林地>荒地>菜地>农田。研究表明,北京市平谷区土壤质量综合评价等级为良好,但空间差异明显,东北部多为山地和林地,综合评价等级为优等,中部及西南部多为农田菜地,综合评价等级为良好和中等,未来应注重科学施肥和土壤质量管理。

板栗人工林根际土壤微生物及环境因子特征

为板栗人工林科学施肥和土壤改良提供理论依据,对广西东兰县、天峨县、林科院、隆安县以及平乐县的板栗人工林根际土壤微生物进行高通量测序及生物信息学分析,研究根际土壤微生物群落结构、多样性差异及与土壤环境因子之间的关系。结果表明:广西5个地区板栗人工林根际土壤环境因子、微生物群落结构与多样性存在较大的差异,整体而言,东兰县板栗人工林根际土壤环境质量表现最差。板栗人工林根际土壤微生物群落优势细菌在门分类水平上均以酸杆菌门和变形菌门为主(>50%),优势真菌均以担子菌门和子囊菌门为主(>95%),而优势菌属在不同地区差异较为明显。Pearson相关性和冗余分析表明,板栗人工林根际土壤微生物群落结构、丰富度和多样性与土壤环境因子有关。土壤脲酶活性与微生物群落Shannon、Chao1、ACE指数显著正相关(P<0.05)。同时土壤脲酶活性与细菌群落优势类群酸杆菌门、Rhizomicrobium及真菌群落优势类群担子菌门、子囊菌门、红菇属、圆孢牛肝菌属、丝盖伞属、锁瑚菌属的相对丰度显著相关(P<0.05)。土壤有效磷、速效钾含量与细菌群落ACE指数显著正相关(P<0.05),并且土壤速效钾含量也是影响板栗人工林根际土壤微生物群落结构变化的重要因子。土壤脲酶活性是影响广西板栗人工林根际土壤微生物群落结构、多样性和优势菌群相对丰度变化的关键驱动因子。

连作对植烟土壤微生物群落与环境因子的影响及相关性分析

为探究连作对植烟土壤微生物群落和土壤环境因子的影响及其相互作用,对连作和轮作植烟土壤进行16S rRNA高通量测序,并对土壤理化性质、酶活性、酚酸类物质等环境因子进行测定。结果表明,连作植烟土壤中鞘氨醇单胞菌属(Sphingomonas)、水恒杆菌属(Mizugakiibacter)、橙色出芽单胞菌属(Gemmatimonas)、人参土黄菌属(Flavisolibacter)相对丰度增加,细菌生态网络复杂度降低;速效钾、有效磷含量增加,水解性氮、硝态氮含量降低,转化酶活性降低,酚酸物质积累。Pearson相关性分析表明,土壤速效钾、有效磷、水解性氮、硝态氮和转化酶以及酚酸等环境因子与鞘氨醇单胞菌属、水恒杆菌属、橙色出芽单胞菌属、人参土黄菌属呈显著相关。可见,连作导致植烟土壤养分失衡,影响土壤微生物群落结构,此结论可为烤烟连作障碍研究提供理论依据。

Study on Spatial-temporal Dynamics of Bt Toxic Protein Expression in Insect-resistant Transgenic Cotton and Its Degradation in Soil

[Objective] This study aimed to investigate the spatial-temporal dynamics of Bt toxic protein expression in insect-resistant transgenic cotton and its degradation in soil. [Method] Btcry1Ac toxic protein expression in roots, stems and leaves of transgenic cotton Guoshen GK45 at different developmental stages and the annual average content of BtCry1Ac toxin protein in the topsoil, rhizosphere soil and following cotton-growing area were explored and analyzed by using enzyme linked immuno sorbed assay (ELISA). [Result] The content of exogenous BtCry1Ac toxin protein decreased during the growth process of insect-resistant transgenic cotton; to be specific, the content of BtCry1Ac toxin protein in cotton stems and leaves decreased more slowly and always maintained a high level, while that in roots decreased rapidly and reached a minimum level to the following plant growth and development stage. BtCry1Ac toxin protein was detected in topsoil of both non-transgenic and transgenic cotton-growing areas, and the content of BtCry1Ac toxin protein increased in topsoil of following cotton-growing area, which was very low in rhizosphere soil. [Conclusion] Determination of Btcry1Ac toxic protein provides scientific basis for the risk assessment of the cultivation of genetically modified crops and the safety evaluation of soil ecosystem.

氧化石墨烯应用于农林种植业中的研究进展

氧化石墨烯(Graphene oxide,GO)是石墨烯的氧化物,其特殊的sp2-sp3杂化结构使其具有很多优异性能,在纳米电子、生物医学和能源储存等多个领域的应用研究较广、较深。近年来,氧化石墨烯又被发现能够促进植物的生长发育,因此,进一步引起了研究人员的广泛关注。本文系统总结了氧化石墨烯对不同植物生长发育的影响,分析了氧化石墨烯的作用机制,探讨了应用过程中可能存在的问题,以期为氧化石墨烯在农林业领域的应用研究提供借鉴,拓宽氧化石墨烯的综合利用途径,促进粮食生产和环境保护的可持续发展。

南方典型稻田土壤-水稻系统环境质量评价

为研究南方典型区域稻田土壤-水稻系统中重金属含量,采集江西省进贤县、金溪县、渝水区、高安市、安福县和兴国县6个水稻主产区典型田块土壤、水稻和灌溉水,重点分析土壤和水稻铅、镉、砷和汞含量及其土壤养分,并采用单因子污染指数和内梅罗综合指数对土壤-水稻系统中重金属含量进行评价。结果表明:研究区稻田土壤pH、有机质、总氮、总磷、总钾、碱解氮、有效磷和速效钾总均值分别为5.48、32.99 g/kg、2.06 g/kg、0.54 g/kg、16.04 g/kg、156.71 mg/kg、14.00 mg/kg和94.98 mg/kg。研究区土壤铅、镉、砷和汞含量总均值分别为35.46、0.18、7.21、0.17 mg/kg,单因子污染指数均小于1,内梅罗综合污染指数为0.56,土壤环境质量等级为清洁;但渝水土壤镉含量为0.37 mg/kg,超过限量标准(0.30 mg/kg),土壤环境质量属于警戒状态。研究区糙米铅、镉、砷和汞的含量总均值分别为0.06、0.17、0.24、0.0086 mg/kg,单因子污染指数均小于1,内梅罗综合污染指数均值为0.77,糙米环境质量等级为警戒限;但兴国和渝水糙米镉含量分别为0.22、0.35mg/kg,均超过限量标准(0.20 mg/kg),环境质量等级分别为警戒限和轻度污染。相关性表明,糙米镉与土壤镉和铅呈显著正相关,而与土壤砷呈显著负相关;糙米砷与土壤砷和有效磷呈显著正相关。总之,重金属镉是调查区域水稻安全性最主要的潜在污染元素,需重点关注兴国和渝水两地水稻食品安全。

聚丙烯酰胺季铵盐大分子药物的环境毒性评价及其实验设计

聚丙烯酰胺季铵盐(PAM-QAS)是丙烯酰胺(AM)与丙烯酰胺季铵盐(AM-QAS)的无规共聚物,因兼具聚丙烯酰胺的土壤改良特性和大分子季铵盐的抑菌特性,在抑制土壤病原真菌、改良和修复病土等领域有良好的应用前景。但人们对季铵盐具有较高环境毒性的传统认识,极大地限制了这类新型大分子药物的应用。如何结合PAM-QAS的应用环境,综合、客观地评价其环境毒性,是大分子药物设计和应用中亟待解决的问题。通过在PAM-QAS中修饰荧光基团直观地观察其在土壤中的吸附与淋溶特性,以及结合土壤吸附和淋溶实验用鱼类经口急性毒性实验和蚯蚓毒性实验评价PAM-QAS经土壤吸附后的实际环境毒性,为PAM-QAS的田间应用提供了一定科学依据。该实验内容涉及聚合物结构表征与应用、大分子药物在复杂环境下的定性检测,以及药物的环境毒性评价等诸多环节,具有一定的综合性与探索性,有利于提高学生的综合素质、科研能力和创新能力。

高光谱遥感技术在地质环境监测中的应用与展望

高光谱遥感技术是一种功能非常强大的综合性学科技术,其以数据的实时性、光谱信息的丰富性、成本的高效益性、覆盖范围的广泛性等特征以及高分辨率和图谱合一的优势,在各个领域上得到了广泛的应用。文章介绍了高光谱遥感技术成像的基本原理、国内外高光谱成像仪和高光谱卫星的发展历程,重点描述了高光谱遥感技术在矿山环境监测、水环境监测与评价、土壤含水率监测等方面的应用成果。高光谱遥感技术面临着“维数灾难”、精确度不足、时效性受限、高光谱遥感数据解译困难等问题,未来可通过协同多平台、利用人工智能模型等方式提高精确度,构建典型的光谱库提高模型的普适性。

土壤微生物的新栖息地:塑料际发生及其生态风险研究进展

微塑料是一种新兴污染物,塑料制品的广泛使用和处理不当对土壤生态系统构成了潜在的环境风险。微塑料在土壤中为微生物提供了新的栖息地,并与周围环境形成了一个独特的生态系统——塑料际。塑料在土壤环境中不易降解,使得塑料际对原始土壤环境造成了严重且持久的生态威胁。目前对塑料际的研究主要集中在水生生态系统,关于土壤塑料际对微生物、微塑料以及土壤环境和其他污染物的影响联合效应等方面的认识仍然非常有限。为探究土壤塑料际中微生物与微塑料相互作用的机制和随之产生的生态效应,本文综述了塑料际作为土壤微生物新的栖息地带来的生态风险相关研究进展,主要讨论了土壤塑料际对微生物的选择效应与微塑料迁移转化的影响、土壤塑料际对土壤结构与土壤碳循环带来的改变以及与其他环境污染物的联合效应。

使用控制图法对原子荧光法测定土壤中砷进行不确定度评定

根据《检测实验室中常用不确定度评定方法与表示》(GB/T 27411-2012)中控制图法,在期间精密度测量条件下按照《土壤和沉积物汞、砷、硒、铋、锑的测定微波消解/原子荧光法》(HJ 680-2013)对土壤中砷进行重复测量,得到34组测量数据。首先计算其正态统计量(A^(2*)),并判断数据的正态性、独立性和分辨力适宜性;其次再绘制控制图,使用失控准则判断测量系统处于受控状态;最后使用t检验判断数据统计上的偏倚受控。三者均满足的情况下,可视期间精密度标准偏差为实验室土壤中砷的测量不确定度。

环境影响评价体系中的土壤环境评价探讨

文章以某化工企业拟建区域的选址为例,对环境影响评价体系中的土壤环境评价进行分析,包括本次所研究的项目概况、环境影响评价体系与土壤环境评价、环境影响评价体系中土壤环境评价的具体实施。经研究可知,在具体的土壤环境影响评价中,现场勘查、评价指标确定、土壤污染预测以及环境影响评价结果分析都是其关键措施。

土壤污染环境监测的质量控制和评价方法

本论文深入研究土壤污染环境监测的质量控制与评价方法。通过对不同监测方法的可行性和效果进行综合分析,提出了科学合理的质量控制体系,并构建了评价模型。实地调查和实验验证结果表明,监测过程中存在的关键问题可以通过相应的改进进行解决,这为提高监测的准确性和实用性提供了重要的指导,从而为土壤污染环境监测领域的发展提供了有益的参考。

土壤修复评估指标体系的构建及其在环境管理中的应用研究

土壤修复是应对土壤污染问题的核心手段之一,而评估指标体系的构建是开展土壤修复工作的基础与关键所在。本研究基于对多种土壤污染类型、修复对象以及修复技术的深入考量,致力于构建一套既科学又合理的土壤修复效果评估指标体系。这一体系旨在实现对土壤修复效果的全面、精准评估与有效监测,从而确保修复工作的质量与效率。本研究旨在系统研究土壤修复评估指标体系的构建方法及其在环境管理中的应用,以期为土壤修复工作提供坚实的科学依据与技术支撑。

土壤污染环境监测的质量控制和评价方法探析

在现代化背景下,受时代特征的影响,人们自身的环保意识逐渐增强。为了有效减少环境危害,相关人员需注重土壤污染环境监测的科学性。随着人们土壤环境保护意识的不断强化,对土壤污染环境监测工作提出了新的标准与要求,相关人员需从数据搜集、监测工作顺序、采样质量、样本测定、样本保存、实验室管理、大数据技术应用等多方面入手,增强土壤环境的保护效果。对此,本文对土壤污染环境监测的质量控制与评价方法展开分析,以此强化整体环境保护效果。

Effects of the vegetation restoration years on soil microbial community composition and biomass in degraded lands in Changting County,China

We evaluated the effects of the number of years of restoration of vegetation on soil microbial community structure and biomass in degraded ecosystems.We investigated the microbial community structure by analyzing their phospholipid fatty acids then examined microbial biomass carbon and nitrogen by chloroform fumigation extraction of restoration soils over several years.The data were compared with those of highly degraded lands and native vegetation sites.The results show that the duration of vegetation on the sites substantially increased microbial biomass and shifted the microbial community structure even after only 4 years.However,microbial communities and biomass did not recover to the status of native vegetation even after 35 years of vegetation cover.A redundancy analysis and Pearson correlation analysis indicated that soil organic carbon,total nitrogen,available potassium,soil water content,silt content and soil hardness explained 98.4%of total variability in the microbial community composition.Soil organic carbon,total nitrogen,available potassium and soil water content were positively correlated with microbial community structure and biomass,whereas,soil hardness and silt content were negatively related to microbial community structure and biomass.This study provides new insights into microbial community structure and biomass that influence organic carbon,nitrogen,phosphorus and potassium accumulation,and clay content in soils at different stages of restoration.

Effect of Organic and Chemical Fertilizer Application on Growth, Yield, and Soil Biochemical Properties of Landrace <i>Brassica napus</i>L. Leaf-and-Stem Vegetable and Landrace (Norabona)

Norabona is generally cultivated in Japan under management systems that use chemical fertilizers and synthetic chemical pesticides. However, the continuous use of these fertilizers and pesticides damages the soil environment and reduces the number of soil microorganisms. There has been little research investigating the effect of organic and chemical fertilizer applications on soil biochemistry and the growth and yield of norabona. In this study, we investigated the effect of organic and chemical fertilizer application on these factors during the norabona growing season from September 2019 to May 2020. Leaf length, shoot height, and shoot width were significantly higher under organic fertilizer management in the early stage of cultivation (in March) than under chemical fertilizer management. However, there was no significant difference between treatments for these growth parameters in later months, nor for any other parameters. Soil TN, and TP contents were significantly higher in the organic fertilizer treatment after harvest than prior to cultivation or after the chemical fertilizer treatment. In addition, soil TC, and volumetric water content were significantly higher in the organic fertilizer treatment than in chemical fertilizer treatment. The higher TC, TN, and C/N ratio in organic fertilizer treated soil appeared to increase the bacterial biomass, leading to enhanced nutrient circulation via N and P circulation activity, producing a rich soil environment with active soil microorganisms.