造纸废水灌溉对湿地土壤中有机质含量的影响

以草浆造纸废水灌溉芦苇湿地为题，通过对污灌后土壤中有机质含量的测定，研究了造纸废水对土壤中有机质的影响，为资源化利用造纸废水提供了理论依据．     

艾比湖湿地湖周典型植物群落下土壤沙化盐化特征研究

选择艾比湖南岸湿地典型植物群落下的土壤为研究对象,对植物样方重要值、盖度和土壤粒度、有机质、总盐等指标进行分析,结果表明:(1)由博河入湖口向东至鸟岛芦苇湿地经鸭子湾到奎屯河下游绕艾比湖湖周60 km典型的植物群落依次为碱蓬植物群落、芦苇植物群落、盐节木植物群落和梭梭植物群落。(2)本研究区典型植物群落下土壤沙化程度在0~20 cm表现为:梭梭植物群落沙化最为严重;芦苇植物群落沙化最轻;而盐节木植物群落和碱蓬植物群落居于二者之间。(3)在垂直方向上,土壤盐分呈现出较强的表聚性。(4)4种典型植物群落下土壤盐化程度表现为碱蓬群落和盐节木群落为极重盐土,芦苇群落为重盐土,梭梭群落为盐渍化土壤,在空间尺度上典型植物群落具有差异性。     

富蕴县耕地土壤环境质量现状

通过在富蕴县建立测土配方施肥示范点，开展了耕地土壤环境质量的调查，结果表明：在富蕴县不同地貌部位0 cm~20 cm耕层土壤中，土壤常量元素的分布与微量元素相比差异较大；在山区土壤中，常量元素与微量元素的含量较高，而在戈壁沙漠地带，土壤中常、微量元素的含量均表现为最低水平；土壤pH值为7.5~8.5，适合作物生长；土壤耕层盐分含量相对较低，仅表现为轻盐化土壤类型，占总耕地面积的12.52%。     

拉鲁湿地芦苇不同部位金属元素富集规律研究

通过在拉鲁湿地布设7个采样点,采集湿地植物芦苇,检测分析K、Na、Ca、Mg、Cu等23种元素在其根、茎、叶、花中的分布特征。结果表明,同一元素在芦苇不同部位及同一部位不同元素的含量、转移能力、富集能力等均差异较大。元素平均质量比范围为0.055 mg/kg(Tl)～2.20×10~4 mg/kg(Na),大部分元素在芦苇不同部位的分布符合根花叶茎这一规律;芦苇对Ca转移能力最强,对Fe的转移能力最弱;芦苇对Fe富集能力最强,特别是根部对Fe的富集系数高达506万倍。     

中国土壤中溴,碘的背景含量

通过对全国八百余个表层土样的分析测试,获得了中国土壤中溴、碘背景含量的总体水平及在各土类中的含量,相对于地壳丰度,中国土壤中溴、碘普遍得到了富集,溴、碘含量分异变化较大,并具有明显的地域分异特征,影响中国土壤中溴、碘含量的主要因素是降水量、土壤吸附体的含量以及某些特殊母质。     

陕西土壤中元素分布的几个特点

通过对陕西省十种主要土壤类型(栗钙土、黑垆土、黄绵土、灰褐土、(土娄)土、棕壤、黄棕壤、水稻土、潮土及褐土)六十个典型剖面的采样分析,系统地研究了十三种必测元素,及四十八种选测元素。在全省土壤中的含量水平与分布特点。研究结果表明,陕西省土壤中元素分布具有以下四个明显特点:(1)与世界土壤和全国土壤相比,陕西土壤中多数元素含量处于中等偏高水平,但有一部分元素(如Se、Mo、I、Br、V、Sn、Zr等)含量远低于世界土壤平均值和全国土壤平均值,其中Se、Mo、I,Br,Sn含量仅为世界及全国土壤平均含量的一半。(2)六十一     

上海地区土壤碳汇功能评估

利用上海市第二次土壤普查资料，2004年-2005年上海耕地地力调查资料，以及2009年实地调查采样、实验分析获得的数据，研究了3个时期上海土壤有机碳的变化特征。结果表明，20多年：来上海土壤有机碳平均含量没有明显变化，土壤有机碳库逐渐减小，从而使得上海城市化过程中土壤成为一种碳源，而不是碳汇。城市郊区以扩大蔬菜、果树、苗木种植为特征的旱地作物种植方式代替水稻田，是城市化影响土地利用类型变化的明显特征，而水稻田土壤有机碳含量高于林地、菜地。种植结构的变化对土壤有机碳含量有重要影响，同时，耕作制度、耕作方式、施肥等农业管理方式也有一定影响。虽然园林绿地得到快速发展，但没有弥补城市化过程导致农田面积减少带来的有机碳损失。     

新疆焉耆县耕地土壤重金属的空间分布及来源解析

在新疆焉耆县采集53个耕地土壤样品,测定其中As、Cd、Cr、Cu、Mn、Ni、Pb和Zn的质量比,基于GIS技术研究其空间分布格局,运用多元统计分析法区分其主要来源。结果表明:焉耆县耕地土壤中Cd、Cr、Ni、Pb和Zn的质量比平均值分别超过新疆灌耕土背景值的0.50、0.40、0.33、1.63和3.92倍;在研究区内As、Cd、Pb质量比呈现由北向南逐渐升高趋势,Cr、Cu、Zn质量比呈现由北向南降低趋势,Mn和Ni质量比出现西部高值区;耕地土壤中As、Cd、Ni和Pb的来源主要受人类活动的影响,Cu和Mn的来源主要受土壤地球化学作用的控制,Cr和Zn的来源可能受人为污染与自然因素共同控制。     

贵州省土壤环境背景值图的编绘研究

一、制图单元的划分 对三十四个统计单元土壤中各元素含量的分布特征,含量水平进行了研究。在获得各统计单元土壤中各元素的背景值后,着重讨论了土壤背景值含量与土壤成土母质、土壤类型、地貌等自然环境因素之间的关系。然后确定其制图单元。 (一)对石灰岩、第四系、页岩、砂岩、砂页岩、冲击母质发育的土壤中元素含量水平与成土母质之间的关系进行了差异显著性检验,结果表明:这六种成土母质发育的土壤中元素背景值含量有显著性差异。其中砂岩发育的土壤中元素Mn、V、Cr、Co、Ni、Cu、Zn、F、Cd的背景值含量均低于其它成土母质发育的土壤。石灰岩母质发育的土壤中Mn、Ni、Zn、     

淮南市耕地质量等级空间分布特征及影响因子研究

通过在立地条件、剖面性状、耕层理化性状、土壤养分、健康状况、农田管理等6个方面选取15～18个指标对淮南市耕地质量进行综合评价,并分析其空间分布特征及主要影响因子。结果表明：淮南市耕地总面积为349 170.18 hm2,耕地质量等级平均为3.70等级,高产田（1～3等级）占比50.67%,中产田（4～6等级）占比44.79%,低产田（7～8等级）占比4.54%;耕地质量空间分布与土壤类型分布相关性明显;耕地土壤有机质、有效磷和速效钾均值分别为24.5 g/kg、2768 mg/kg和140 mg/kg,均处于中等水平,质量等级较高的耕地,其土壤主要养分含量也相对较高。耕地质量主要影响指标为灌溉能力、排水能力、地形部位及土壤养分含量。     

Spatial variability of soil salinity in coastal saline soil at different scales in the Yellow River Delta,China

The objectives of this study were to explore the spatial variability of soil salinity in coastal saline soil at macro, meso and micro scales in the Yellow River delta, China. Soil electrical conductivities (ECs) were measured at 0–15, 15–30, 30–45 and 45–60 cm soil depths at 49 sampling sites during November 9 to 11, 2013. Soil salinity was converted from soil ECs based on laboratory analyses. Our results indicated that at the macro scale, soil salinity was high with strong variability in each soil layer, and the content increased and the variability weakened with increasing soil depth. From east to west in the region, the farther away from the sea, the lower the soil salinity was. The degrees of soil salinization in three deeper soil layers are 1.14, 1.24 and 1.40 times higher than that in the surface soil. At the meso scale, the sequence of soil salinity in different topographies, soil texture and vegetation decreased, respectively, as follows: depression >flatland >hillock >batture; sandy loam >light loam >medium loam >heavy loam >clay; bare land >suaeda salsa >reed >cogongrass >cotton >paddy >winter wheat. At the micro scale, soil salinity changed with elevation in natural micro-topography and with anthropogenic activities in cultivated land. As the study area narrowed down to different scales, the spatial variability of soil salinity weakened gradually in cultivated land and salt wasteland except the bare land.     

Status and habitat preferences for endemic inhabitants of fiddler crab Uca formosensis in Hsiang-Shan wetland, Taiwan

This article reports on soil samples collected from Hsiang-Shan wetland, Taiwan. Canonical discriminant analysis (CDA) was applied to identify an existing habitat type's scheme by identifying the physico-chemical properties of sediment in Hsiang-Shan wetland. The three constructed discriminant functions (CDFs) showed a marked contribution by most of the discriminant variables, and the recognition capacities in these three CDFs were 49.5, 32.8 and 17.7%. Our study revealed that the most important latent factors in Hsiang-Shan wetland are soil texture-caused factor, ocean current-caused factor, nutrient-caused factor, and the redox reaction-caused factor. And the most sensitivity parameters in this habitat followed the descending order: OBD, EC, Eh, sand, TN, porosity, STP, silt, VCP and pH. And the inhabited sediment properties for U. formosensis in terms of soil texture are sand, silt, and clay (34.05, 29.72, and 32.35%, respectively): that is clay loam soil. We also found that U. formosensis preferred to inhabit the upper intertidal zone, spending 8.41% of the time submerged. Vegetation coverage on the ground was less than 2.20%, showing that it preferred to live in a bare intertidal habitat. Concerning nest choosing, excavating burrows is more difficult when a high soil penetration force is required, and in this study the soil penetration force for 20 cm was found to be is 45.98 N/cm(2). The results will be helpful in developing a methodology for use by the government in refining its management programs.     

The effects of land use changes on some soil properties in İndağı Mountain Pass – Çankırı, Turkey

Understanding spatial variability of dynamic soil attributes provides information for suitably using land and avoiding environmental degradation. In this paper, we examined five neighboring land use types in Indagi Mountain Pass - Cankiri, Turkey to spatially predict variability of the soil organic carbon (SOC), bulk density (BD), textural composition, and soil reaction (pH) as affected by land use changes. Plantation, recreational land, and cropland were the lands converted from the woodland and grassland which were original lands in the study area. Total of 578 disturbed and undisturbed soil samples were taken with irregular intervals from five sites and represented the depths of 0-10 and 10-20 cm. Soil pH and BD had the lower coefficient of variations (CV) while SOC had the highest value for topsoil. Clay content showed greater CV than silt and sand contents. The geostatistics indicated that the soil properties examined were spatially dependent to the different degrees and interpolations using kriging showed the dynamic relationships between soil properties and land use types. The topsoil spatial distribution of SOC highly reflected the changes in the land use types, and kriging anticipated significant decreases of SOC in the recreational land and cropland. Accordingly, BD varied depending on the land use types, and also, the topsoil spatial distribution of BD differed significantly from that of the subsoil. Generally, BD greatly decreased in places where the SOC was relatively higher except in the grassland where overgrazing was the more important factor than SOC to determine BD. The topsoil spatial distributions of clay, silt, and sand contents were rather similar to those of the subsoil. The cropland and grassland were located on the very fine textured soils whereas the woodland and plantation were on the coarse textured soils. Although it was observed a clear pattern for the spatial distributions of the clay and sand changing with land uses, this was not the case for the silt content, which was attributed to the differences of dynamic erosional processes in the area. The spatial distribution of the soil pH agreed with that of the clay content. Soils of the cropland and grassland with higher amounts of clay characteristically binding more cations and having higher buffering capacities had the greater pH values when compared to the soils of other land uses with higher amounts of sand naturally inclined to be washed from the base cations by the rainwater.     

Land use impact on soil quality in eastern Himalayan region of India

Quantitative assessment of soil quality is required to determine the sustainability of land uses in terms of environmental quality and plant productivity. Our objective was to identify the most appropriate soil quality indicators and to evaluate the impact of six most prevalent land use types (natural forestland, cultivated lowland, cultivated upland terrace, shifting cultivation, plantation land, and grassland) on soil quality in eastern Himalayan region of India. We collected 120 soil samples (20 cm depth) and analyzed them for 29 physical, chemical, and biological soil attributes. For selection of soil quality indicators, principal component analysis (PCA) was performed on the measured attributes, which provided four principal components (PC) with eigenvalues >1 and explaining at least 5 % of the variance in dataset. The four PCs together explained 92.6 % of the total variance. Based on rotated factor loadings of soil attributes, selected indicators were: soil organic carbon (SOC) from PC-1, exchangeable Al from PC-2, silt content from PC-3, and available P and Mn from PC-4. Indicators were transformed into scores (linear scoring method) and soil quality index (SQI) was determined, on a scale of 0–1, using the weighting factors obtained from PCA. SQI rating was the highest for the least-disturbed sites, i.e., natural forestland (0.93) and grassland (0.87), and the lowest for the most intensively cultivated site, i.e., cultivated upland terrace (0.44). Ratings for the other land uses were shifting cultivation (0.60)?>?cultivated low land (0.57)?>?plantation land (0.54). Overall contribution (in percent) of the indicators in determination of SQI was in the order: SOC (58 %)?>?exch. Al (17.1 %)?>?available P (8.9 %)?>?available Mn (8.2 %)?>?silt content (7.8 %). Results of this study suggest SOC and exch. Al as the two most powerful indicators of soil quality in study area. Thus, organic C and soil acidity management holds the key to improve soil quality under many exploitatively cultivated land use systems in eastern Himalayan region of India.     

镇江地区土壤中有机氯农药残留状况研究

2006年11月采集了镇江地区69个土壤表层样品，利用ASE萃取后使用GC（ECD）法测定样品中的BHC和滴滴涕的含量。结果表明，镇江地区土壤中的BHC的检出率不高，但是滴滴涕的检出率比较高；冲积平原的检出率高于林地和滩涂；蔬菜和水稻种植区域的污染比草地、灌木丛和林地严重。     

Soil water, salt, and groundwater characteristics in shelterbelts with no irrigation for several years in an extremely arid area

This paper is based on long-term monitoring data for soil water, salt content, and groundwater characteristics taken from shelterbelts where there has been no irrigation for at least 5 years. This study investigated the distribution characteristics of soil water and salt content in soils with different textures. The relationships between soil moisture, soil salinity, and groundwater level were analyzed using 3 years of monitoring data from a typical oasis located in an extremely arid area in northwest China. The results showed that (1) the variation trend in soil moisture with soil depth in the shelterbelts varied depending on soil texture. The soil moisture was lower in sandy and loamy shelterbelts and higher in clay shelterbelts. (2) Salinity was higher (about 3.0 mS cm^?1) in clay shelterbelts and lower (about 0.8 mS cm^?1) in sandy shelterbelts. (3) There was a negative correlation between soil moisture in the shelterbelts and groundwater level. Soil moisture decreased gradually as the depth of groundwater table declined. (4) There was a positive correlation between soil salinity in the shelterbelts and the depth of groundwater table. Salinity increased gradually as groundwater levels declined.     

Assessment of the Heavy Metal Pollution Effects on the Soil Respiration in the Baix Llobregat (Catalonia, NE Spain)

A main goal of investigations is to determine could a soilrespiration be an indicator of the soil pollution. In this case a measured levelof the soil oxygen consumption depends of its pollution. It alsomeans that the pollution reduces biological processes in edaphon.Investigated soil samples were taken from polluted andnon-polluted places in the Baix Llobregat near Barcelona (Catalonia, NE Spain). Soil samples were taken from the top ofsoil (0–5 cm) without a litter. Soil analysis were done, determining percentage shares of coarsefragments, coarse sand, fine sand, coarse silt, fine silt, clay,CaCO₃, organic matter as well as water pH and conductivityCE (1:5 [mS cm^-1]). Also were determined (in mg kg^-1)quantities of heavy metals, as Fe, Al, Mn, Zn, Cr, Ni, V, Cu, Cd, Pb.The soil respiration was investigated in temperatures15 and 30 °C and with controlled humidity.The respiration in 30 °C is number of times greater thenin 15 °C both for polluted and non-polluted soils.Particularly high coefficients of correlation between the soilrespiration and soil pollution in polluted soils were obtainedfor Pb: r = 0.75 in 15 °C and r = 0.98 in30 °C; for Ba: 0.90 and 0.57; for V: 0.99 and 0.81. In non-polluted soils highest correlation coefficients are for Pb: r = 0.70 in 15 °C; Fe: 0.60 and 0.72; Al: 0.68 and0.64; Mn: 0.51 and 0.66; Ba: 0.63 and 0.61; Cr: 0.94 and0.70; Ni: 0.64 and 0.65; Cu: 0.69 and 0.48; as well as V: 0.62in 15 °C; and Cd: 0.69 in 15 °C.This way the soil respiration could be a good indicator of the soil pollution.     

Effects of wetland recovery on soil labile carbon and nitrogen in the Sanjiang Plain

Soil management significantly affects the soil labile organic factors. Understanding carbon and nitrogen dynamics is extremely helpful in conducting research on active carbon and nitrogen components for different kinds of soil management. In this paper, we examined the changes in microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), dissolved organic carbon (DOC), and dissolved organic nitrogen (DON) to assess the effect and mechanisms of land types, organic input, soil respiration, microbial species, and vegetation recovery under Deyeuxia angustifolia freshwater marshes (DAMs) and recovered freshwater marsh (RFM) in the Sanjiang Plain, Northeast China. Identifying the relationship among the dynamics of labile carbon, nitrogen, and soil qualification mechanism using different land management practices is therefore important. Cultivation and land use affect intensely the DOC, DON, MBC, and MBN in the soil. After DAM soil tillage, the DOC, DON, MBC, and MBN at the surface of the agricultural soil layer declined significantly. In contrast, their recovery was significant in the RFM surface soil. A long time was needed for the concentration of cultivated soil total organic carbon and total nitrogen to be restored to the wetland level. The labile carbon and nitrogen fractions can reach a level similar to that of the wetland within a short time. Typical wetland ecosystem signs, such as vegetation, microbes, and animals, can be recovered by soil labile carbon and nitrogen fraction restoration. In this paper, the D. angustifolia biomass attained natural wetland level after 8 years, indicating that wetland soil labile fractions can support wetland eco-function in a short period of time (4 to 8 years) for reconstructed wetland under suitable environmental conditions.     

Fluoride in fractionated soil samples of Ajmer district,Rajasthan

The natural abundance of fluoride in soils of the Ajmer distict, Rajasthan was examined. From undisturbed soil, the top 15 cm of the profile was examined and the soil split into fractions based on sand, silt and clay particle size. Clay contained a high amount of fluoride, whereas sand and silts are enriched with much less fluoride. The relation between the soil fractions in observed clay fraction fluoride content matched groundwater fluoride variation. However, the enrichment of fluoride material extracted from the largest soil fraction had considerably lower amounts of clay relative to that from the smaller fractions.     

Land-Cover Changes and Its Impacts on Ecological Variables in the Headwaters Area of the Yangtze River, China

Land cover changes affect ecological landscape spatial pattern, and evolving landscape patterns inevitably cause an evolution in ecosystem functionality. Various ecological landscape variables, such as biological productivity (plant biomass and stock capacity), soil nutrients (organic matter and N content) and water source conservation capacity are identified as landscape function characteristics. A quantitative method and digital model for analyzing evolving landscape functionality in the headwaters areas of the Yangtze River, China were devised. In the period 1986–2000, patch transitions of the region's evolving landscapes have been predominantly characterized by alpine cold swamp meadow, with the highest coverage tending to be steppified meadow or steppe, and desertification landscape such as sand and bare rock land expansion. As the result of such changes, alpine swamp areas decreased by 3.08 × 10³ km² and the alpine cold sparse steppe and bare rock and soil land increased by 6.48 × 10³ km² and 5.82 × 10³ km², respectively. Consequently, the grass biomass production decreased by 2627.15 Gg, of which alpine cold swamp meadows accounted for 55.9% of this loss. The overall stock capacity of the headwaters area of the Yangtze River decreased by 920.64 thousand sheep units, of which 502.02 thousand sheep units decreased in ACS (Alpine cold swamp) meadow transition. Soil organic matter and N contents decreased significantly in most alpine cold meadow and swamp meadow landscape patches. From 1986 to 2000 the total losses of soil organic matter and total N in the entire headwaters region amounted to 150.2 Gkg and 7.67 Gkg. Meanwhile, the landscape soil water capacity declined by 935.9 Mm³, of which 83.9% occurred in the ACS meadow transition. In the headwater area of the Yangtze River, the complex transition of landscape resulted in sharp eco-environmental deterioration. The main indication for these changes involved the intensity of the climate in this region is becoming drier and warmer, resulting in a gradual degradation of the permafrost.