开封黑岗口引黄灌区稻麦轮作下农田土壤剖面重金属分布特征

引黄灌区是我国重要的农业生产基地,其土壤重金属赋存状况直接关系到农业的可持续发展。本研究以黑岗口引黄灌区开封北郊稻麦轮作下农田土壤为研究对象,采集了耕作层(0~15 cm与15~30 cm)与剖面(0~100 cm)土壤样品,对其土壤剖面主要性质与重金属Pb、Cd、Cu和Zn的积累特征进行了分析。结果表明:(1)长期引黄灌溉及稻麦轮作下,开封北郊农业土壤主要性质在剖面上表现出明显的分异特征:总有机碳(TOC)与全氮(TN)含量主要分布在耕作层土壤,而30 cm以下的土层其含量明显降低;全磷(TP)含量在各土壤层中无明显差异;在部分土壤剖面中CaCO3呈现出明显的淀积层。(2)耕作层(0~30 cm)土壤中重金属Pb、Cu、Zn的含量与研究区背景值相当,而Cd含量显著高于背景值。除少部分剖面含量超标外,Cd、Pb、Cu、Zn的平均含量均未超出WHO限值,且远低于我国农业土壤环境质量标准。因子分析源解析表明:引黄灌区土壤中Pb、Cu和Zn具有相似的来源和迁移特性,而Cd的来源和迁移特性具有特殊性,它可能与当地的化肥施用等农业活动有关。(3)土壤剖面中Cu和Zn具有明显的表聚现象,Pb的表聚作用不明显,而Cd在剖面各层土壤含量具有较大变异性,这与重金属的自身属性、土壤剖面性质和当地的耕作条件有较大相关性。(4)Cu和Zn在土壤剖面主要以有机结合态和残余态形式存在;Pb的残余态、有机态以及铁锰氧化态含量也较高,且Pb的全量与有机结合态含量百分比变化呈现出一定的相似性;而Cd具有较高的碳酸盐结合态和离子交换态,表明Cd在土壤中具有较强的移动性,预示Cd的潜在健康风险较高。     

中国土壤系统分类中“红色砂、页岩、砂砾岩和北方红土岩性特征”的比较研究及诊断标准的修订

对《中国土种志》收录的红色砂岩、页岩、砂页岩、砂砾岩、北方新近纪红土、北方第四纪红土剖面资料,和近几年辽宁红土研究中新积累的第四纪红土剖面资料进行统计分析,结果表明:中国北方新近纪和第四纪红土颜色属性中的色调为5YR、2.5YR和10R,红色砂岩、页岩、砂页岩、砂砾岩颜色属性中的色调为5YR、2.5YR、10R和7.5R.中国土壤系统分类针对“红色砂、页岩、砂砾岩和北方红土岩性特征”规定的色调为2.5R ～ 5R、7.5R～10R与大部分情况不符.根据研究结果,建议将“红色砂、页岩、砂砾岩和北方红土岩性特征”修订为“红色砂岩、页岩、砾岩和半成岩状态红土岩性特征”;关于色调的规定修订为“5YR、2.5YR、10R或者更红”;如果明确规定明度值和彩度值的范围,则需要标明是干态或是润态.     

Late Quaternary paleosols and their paleoenvironmental significance along the Andean piedmont,Eastern Bolivia

The Andean piedmont of eastern Bolivia is situated at the southern margin of Amazonia characterized by an overall humid climate regime with a marked contrast between the rainy and dry seasons. The nearby Subandean foothills deliver abundant sandy sediments to the piedmont, leading to a complex array of sediments and paleosol horizons. Within this setting, the presented study analyzes four profiles of paleosol-sediment-sequences along incised ephemeral streams near Santa Cruz de la Sierra with a focus on past pedogenic variability in the context of the regional late Quaternary geomorphic and environmental evolution.     

景电灌区几种土地利用方式土壤有机碳和养分特征研究

对景电灌区土壤次生盐渍化的1年生枸杞地和多年生枸杞地、未盐渍化的小麦地和苜蓿地4种土地利用方式土壤有机碳和养分状况进行对比研究,结果表明:在0~60cm土层,小麦地土壤有机碳含量及其密度、全氮和速效磷含量均最高,苜蓿地均最低;土壤全氮与有机碳含量呈极显著正相关(r=0.791,P0.01);4种利用方式C/N比值均较低,多年生枸杞地C/N比值最高,1年生枸杞地最低;4种利用方式速效钾含量无显著差异;苜蓿地容重显著高于其他3种利用方式,这与其低的有机碳含量密切相关(r=0.420,P0.01)。与小麦地相比,1年生枸杞地土壤有机碳含量及其密度显著降低,全氮和速效磷含量有所降低;与1年生枸杞地相比,多年生枸杞地土壤有机碳含量及其密度有所增加,全氮含量显著降低,速效磷含量显著增加。这意味着该区耕地土壤发生次生盐渍化以后,土壤性状恶化;种植枸杞使次生盐渍化土壤性状有所改善。     

Soil properties, crop productivity and irrigation effects on five croplands of Inner Mongolia

In the Horqin Sand Land, more than half of the original pasture area has been converted to farmland over the last century. A field experiment was conducted from 2000 to 2001 on five croplands in the Horqin Sand Land of Inner Mongolia to examine differences in soil properties, crop productivity and irrigation effects across different soils in the region to assess their relative suitability for cultivation, in the face of continued pressure for conversion of these generally fragile, sandy soils to agriculture.Two irrigated croplands studied were originally sandy meadow (ISM) and sandy grassland (ISG), and three dry croplands were from sandy meadow (DSM), sandy grassland (DSG) and fixed sand dunes (DFD). Results showed that most measured properties of soils, and crop productivity, differed among the five croplands. The silt + clay fraction, bulk density, organic matter content, total N and P, available N and P, average soil moisture and temperature, plant height and aboveground biomass were as follows in the DSM|DSG|DFD soils: 51.1%|47.5%|24.3%; 1.44 g/cm³|1.49 g/cm³|1.58 g/cm³; 6.3 g/kg|4.6 g/kg|3.4 g/kg; 0.55 g/kg|0.33 g/kg|0.21 g/kg; 0.21 g/kg|0.17 g/kg|0.13 g/kg; 27.0 mg/kg|13.7 mg/kg|7.7 mg/kg; 2.9 mg/kg|2.9 mg/kg|3.0 mg/kg; 9.4%|7.0%|6.2%; 21.4 °C|21.7 °C|22.0 °C; 225 cm|220 cm|181 cm; and 2116 g/m²|1864 g/m²|1338 g/m². Corresponding values for ISM|ISG soils were: 54.3%|47.9%; 1.42 g/cm³|1.49 g/cm³; 8.5 g/kg|6.4 g/kg; 0.58 g/kg|0.42 g/kg; 0.20 g/kg|0.19 g/kg; 29.0 mg/kg|23.3 mg/kg; 4.7 mg/kg|7.9 mg/kg; 13.0%|10.1%; 21.0 °C|21.1 °C; 266 cm|245 cm; and 2958 g/m²|2702 g/m².In general, the ecological origin of a cropland was a stronger determinant of its current characteristics than was irrigation history, although irrigation was correlated with significantly increased organic matter content, some soil nutrient levels, and aboveground biomass productivity. Results indicate that fixed sand dunes should not be converted to cropland because of their very sandy and poorer soil, lower biomass productivity and greater wind-erosion risk. Although both the sandy meadow and sandy grassland may be reclaimed for farming, the cropland derived from the sandy meadow had higher resistance to wind erosion and higher crop productivity, so is somewhat more suitable than sandy grassland.     

豫中黄土地区全新世土壤剖面成壤环境变化研究

通过对河南新郑黄土-土壤剖面的野外考察及室内的磁化率、烧失量、碳酸钙及粒度分析研究,认为:豫西山地山前丘陵台地的完整黄土-土壤剖面,是在气候波动变化的条件下形成的。全新世气候的变化,导致了以风尘堆积为主的成黄土期与以风化成壤作用为主的成壤期互相更迭。在全新世早期,风尘堆积旺盛,形成了过渡性黄土层(Lt),在8500aB.P.～3100aB.P.的全新世大暖期,发育了浊红棕色古土壤(S0)。这一时期降水丰沛,土壤水分充足,导致了古土壤层(S0)及其以下的过渡层(Lt)、马兰黄土层(L1)顶部都受到了明显的淋溶作用影响,而完全脱钙。3100a B.P.之后,气候恶化,沙尘暴活动显著增强,加之黄河下游人类活动影响不断加剧,黄泛平原风沙活动十分强烈,风尘堆积形成了沙质黄土(L0)。1500aB.P.以来,近代黄土持续堆积,由于气候的转暖与人类农业耕作影响在持续堆积的近代黄土L0表层形成了现代土壤(TS)。     

天山北麓褶丘陵的特征与演化

对北天山山前四排褶皱丘陵的地貌特征、组成地层与构造特征进行了研究,在此基础上探讨了山前褶皱丘陵的演化历史。第一排褶皱形成于晚第三纪中新世。上新世晚期,早更新世初期,第二排褶皱开始形成。早更新世晚期,中更新世初期,第三排褶皱开始形成。晚更新世晚期,至全新世以来,第二排褶皱与第三排褶皱一直在持续隆升,同时第四排褶皱也开始形成。     

天山北坡林沿土壤养分含量的区域差异特征研究

以天山北坡为研究区域, 采用野外调查与试验分析相结合的方法, 选取5个土壤养分指标: 有机质、速效氮、速效磷、速效钾和总盐, 应用多元统计分析方法, 分析了天山北坡3个区段(昭苏-特克斯、新源-巴音布鲁克、巴里坤-伊吾)林沿土壤不同层位(0~5 cm、5~20 cm、20~40 cm)养分含量的分布特征及差异性。结果表明: 天山北坡西段(昭苏-特克斯、新源-巴音布鲁克)土壤养分含量比天山北坡东段(巴里坤-伊吾区域)高。3个区段不同深度土壤有机质、速效氮、速效磷、速效钾含量均存在明显差异, 其中0~5 cm土层有机质、速效氮、速效磷、速效钾的平均含量均比5~20 cm、20~40 cm高; 5~20 cm土层有机质、速效氮、速效磷、速效钾的平均含量均比20~40 cm高; 总盐含量不具有明显的垂直分层现象。按全国第2次土壤普查标准, 天山北坡3个区段土壤均属肥沃级。昭苏-特克斯区段、新源-巴音布鲁克区段0~5 cm、5~20 cm、20~40 cm土壤养分各指标含量变化具有一定的规律, 而巴里坤-伊吾区段土壤养分各指标含量变化具有良好的独立性。天山北坡西段(昭苏-特克斯、新源-巴音布鲁克)植被类型较多, 植被覆盖度较高, 土壤较为肥沃, 大部分区域为夏牧场, 人类活动以放牧为主, 对该区段土壤要防止过度放牧所造成的植被退化与水土流失。天山北坡东段(巴里坤-伊吾)因土壤中砾石较多, 植被类型较少, 植被覆盖度较低, 人类活动包括放牧、林业种植与旅游, 与西段相比东段土壤的养分含量较低, 所以应以保持生境原貌为主, 避免人为扰动后的生境退化。     

土壤厚度演化模型理论方法研究进展

全球平均土壤厚度仅约为1 m,但土壤厚度的空间分布信息在地貌、生态及水文科学等领域的研究和实践中具有重要价值。由于其具有显著的空间异质性,基于现有土壤制图产品、地球物理勘测及经验统计模型难以获取流域尺度土壤厚度分布信息,亟待发展土壤厚度预测的过程机理模型。本文回顾了土壤厚度演化模型理论方法的研究进展,评价了不同土壤生成及输移模型的适用性。研究指出土壤化学风化成土等机理仍不清晰是制约模型发展的理论瓶颈。此外,模型的方法体系仍需完善,亟待进一步发展描述土壤生成和输移的函数形式及其参数的估计方法等,指出物理与随机结合的模拟方法以及基于数学物理途径的参数确定方法等有望解决模型应用中遇到的难题。最后,在土壤厚度演化模型基础上,提出发展基于流域协同演化理论的土壤发生学模型是定量预测土壤理化全要素发生所亟需突破的难点之一。     

节水灌溉对盐渍土盐分调控与土壤微生物区系的影响

河套灌区是我国大型自流灌区之一,盐渍化是该区土壤主要障碍因素之一。目前,河套灌区葵花田生育期灌溉量约为1 100～1 200 m3hm-2,灌溉用水量偏大和地下水位偏高已成为制约当地灌溉农业可持续发展的主要障碍:一方面,水资源浪费严重;另一方     

北岳恒山地道黄芪产地生态环境评价

针对山西省北岳恒山地道黄芪产地生态环境现状，采用现场布点采样和实验室分析相结合的方法，利用国家现有标准和评价体系对产地大气质量、灌溉水质量和土壤质量进行测定和评价。结果表明：北岳恒山地道黄芪主产地大气质量、灌溉水质量和土壤环境质量均符合国家有关标准，无任何污染，土壤肥力中等，有机质含量高。土壤属砂质粘壤土，形成了地道黄芪生长的独特生态环境。     

河套灌区中度盐渍化土壤改良产品筛选研究

为寻求适宜内蒙古河套灌区中度盐渍化土壤改良产品,选择了具有代表性的4种土壤改良剂和3种抗盐碱专用肥,通过田间及室内试验研究施用各土壤改良产品对土壤含盐量、土层贮盐量及油葵产量构成等因素的影响。结果表明:施用各种土壤改良产品处理均显著优于对照处理;其中抗盐碱专用肥在提高作物出苗率、保苗率及增产方面占优,而土壤改良剂在土壤脱盐及降低土壤碱性方面更具优势;在各种改良产品中丹路菌肥(T5处理)在提高葵花出苗率、保苗率及增产方面效果最佳,在土壤脱盐及降低土壤碱性方面也较为突出;磷石膏(T1)处理在土壤脱盐及降低土壤碱性方面效果最佳,故将丹路菌肥和磷石膏作为本研究筛选结果,建议在盐渍化土壤改良中推广使用。     

2000-year environmental history of a karstic lake in the Mediterranean Pre-Pyrenees: the Estanya lakes (Spain)

The sediment record of the Estanya lakes (Pre-Pyrenees, Spain) indicates that this region was intensely affected by land use during the Middle and Modern ages, which contrasts with the present-day poor socioeconomic development of the region. The correlation between sediment and biotic data and well-known historical events suggests a reliable history of environmental changes in this area during the last 2000 years. Changes in lake level were mainly controlled by climatic factors, whereas properties such as lithology, organic carbon, ostracods and pollen content are mainly associated with lake management and land use. Major sedimentological changes resulted from the use of the lake for hemp retting at the start of the XIVth century. Subsequent depopulation of the area in the XXth century led to the progressive recovery of the lacustrine ecosystem.     

65 Years Long-term Experiments at Thyrow. Results for Sustainable Crop Production at Sandy Soils

In 1937, K. Opitz founded an agricultural experimental station at Thyrow (Brandenburg County, Germany) where field experiments with a duration of 25 to 65 years still are being managed representing classical long-term field experiments. The location is characterized by low soil fertility, low silty sand soil and unstable water supply and represents arable land of low quality in the lowland of Northern Germany. The long-term collection of results of three different experiments lead to the following approaches for sustainable plant production on marginal sand soils: ” In cereal cropping a well-balanced crop rotation is more important than high amounts of soil organic matter. ” Sustainable reproduction of soil organic matter needs at least 10t/ha and year farm yard manure or straw manure in every second year. ” Irrigation is effective only if additional mineral N fertilizer is applied.     

中国北方主要农区农田氮磷淋溶特征与时空规律

中国北方黑土区、潮土区和褐土区是我国农业主产区,大水大肥问题尤为突出,氮磷淋溶是全国典型的地下水污染来源。然而,中国北方主要农区农田氮磷淋溶特征和时空规律尚不清楚。本文利用田间原位监测和文献荟萃分析方法,系统分析了中国北方主要农区285个监测点年的4种主要种植模式(春玉米、冬小麦-夏玉米、露地蔬菜、保护地蔬菜)农田氮磷淋溶特征与时空规律。研究结果表明,中国北方4个主要种植模式的平均氮和磷淋溶强度分别为:保护地蔬菜117.5 kg(N)·hm~(-2)和0.74 kg(P)·hm~(-2),露地蔬菜51.7kg(N)·hm~(-2)和0.10kg(P)·hm~(-2),冬小麦-夏玉米轮作49.9kg(N)·hm~(-2)和0.07kg(P)·hm~(-2),春玉米30.7kg(N)·hm~(-2)和0.09kg(N)·hm~(-2)。与粮田相比,蔬菜田的高水肥投入决定了其较高的氮磷淋溶量。受土壤质地以及区域间水肥管理差异的影响,同一种植模式下,总氮淋溶强度为黑土区褐土区潮土区。农田氮磷淋溶年际间变化主要受降雨强度的影响,总氮淋溶量与降雨强度呈正线性相关关系,尤其前一年无淋溶事件发生背景下,下一年的淋溶量会急剧增加。空间尺度上,潮土区和褐土区是氮素淋溶的主要风险区。值得注意的是一些蔬菜种植面积尤其是保护地蔬菜种植面积占比较大的省份表现出较高的氮磷淋溶风险。综上,北方主要农区农田氮磷淋溶风险以氮为主,磷的淋溶风险也不容忽视。潮土区和褐土区是氮素淋溶的主要风险区。区域尺度上,氮磷淋溶主要来自粮田,但菜田面积越大,氮磷淋溶风险越高。     

A comparison of soil degradation under smallholder farming and large-scale irrigation land use in Kano State,Northern Nigeria

Changes in soil properties under two land use types: smallholder farms and large-scale irrigated agriculture were investigated over a period of 13 and 14 years respectively using the following parameters: particle size distribution, soil pH, exchangeable cations, cation exchange capacity, total organic carbon and nitrogen and total and available potassium and phosphorus. Results indicate that more adverse changes took place in soils under large-scale irrigation than in those under smallholder farms during the periods under consideration. Agricultural sustainability is more likely to be achieved for smallholder farms than for large-scale irrigation where soil degradation resulting from loss of fine soil particles through erosion can be a serious hindrance to long-term land use. In order to achieve agricultural sustainability in Kano State, it is recommended that chemical fertilizers be incorporated into the smallholder farming system, while the adoption of suitable soil conservation practices would make the large-scale irrigation systems more stable and sustainable.     

沙坡头区直插式根灌条件下土壤水分变化分析

为提高沙坡头地区造林过程中的水分利用效率,制定最优化的灌溉制度,在宁夏中卫沙坡头自然保护区,两年生固沙梭梭(Haloxy lonammodendron)林展开直插式根灌节水试验,分析和模拟直插式根灌过程中土壤水分入渗和消退规律。结果表明:1)直插式根灌过程中,土壤含水量随灌水时间的变化符合Logistic曲线变化;停灌后,土壤水分消退规律符合幂函数模型变化。2)本试验条件下,不同土层土壤水分最大入渗速率依次为60 cm40 cm80 cm100 cm20 cm,达到最大入渗速率的时间40 cm土层最短,平均为1.22 h,100 cm土层最长,平均为4.57 h;1 m深土层土壤水分最大入渗速率平均为1.65%·h-1,达到最大入渗速率的时间平均为2.16 h。3)根据模拟结果,建议沙坡头区梭梭林直插式根灌灌溉周期为4 d左右,单次灌水时间以6~10 h为宜。4)停灌2 h后,各土层土壤含水量消退速率随土层深度增加而增大,停灌后48 h,各土层土壤水分消退速率基本为零;梭梭全生长期,1 m深土层土壤水分消退速率在结实期最大,为2.20%·h-1,休眠期最小,为1.31%·h-1。5)直插式根灌对20 cm土层土壤水分的影响最小,对60 cm土层土壤水分影响最大;灌溉过程中,土壤水分等值线以60 cm土层等值线为中心,向表层和深层土壤辐射状分布,灌后各土层平均土壤含水量,20 cm和60 cm土层与其他各土层之间差异显著(P0.05)。研究表明,直插式根灌的土壤水分入渗规律符合Logistic曲线变化,消退规律符合幂函数曲线变化,直插式根灌对20 cm土层土壤水分的影响最小,对60 cm土层土壤水分影响最大,沙坡头区梭梭林直插式根灌灌溉周期为4 d左右,单次灌水时间以6~10 h为宜。     

土壤孔隙结构定量化研究进展

土壤孔隙结构是土壤结构的重要方面,土壤大孔隙引起的优先流和溶质优先迁移与地下水污染、养分流失和灌溉水浪费都有着密切的关系;对土壤孔隙结构的研究具有重要的实践意义和指导作用。本文在综合国内外研究文献的基础上,对前人研究进行系统总结,介绍土壤孔隙结构的获取手段、孔隙结构的表征和模拟方法,并且对今后土壤孔隙结构研究的热点进行了展望,以期为今后进行土壤孔隙结构建模的深入研究提供帮助。