长江以南东部丘陵山区土壤可蚀性K值研究

以土壤亚类为基础,从土种入手,依据第二次土壤普查资料建立了我国东产丘陵区各土种的理化性质数据库。应用土壤可蚀性方法,计算出各土种的土壤可蚀性Ｋ值,用面积进行加权平均,经分类分级后,连续到相应的土壤图上,得到我国东部丘陵区土壤可蚀性Ｋ值图及其分布规律。     

Changes in status of the frog (Rana temporaria) and the toad (Bufo bufo) on part of the East Anglian Fenland in Britain

An attempt has been made to determine fluctuations in status of the frog (Rana temporaria) and the toad (Bufo bufo) on parts of the Fens (10 km squares TL38, 39, 48 and 49). Information from Fenland workers indicated that both species were common from at least as far back as 1900 up until the 1930s. Severe declines occured in the 1940s, 1950s and 1960s, and by the 1970s both species were very rare. Improved drainage and the marked change from pasture to arable, with associated loss of suitable wet and damp habitat, are believed to have been responsible for the early decreases. Again, loss of habitat was likely to be the main factor causing the later declines, but pesticides probably also contributed. At present, about half of the dykes containing water at a depth which frogs in other areas normally select for spawning dry out before tadpole metamorphosis would be completed.     

Soil cover of mountain forests in the East Khubsugul region of Mongolia

Specific features of soil formation and soil cover patterns in mountain forests of the East Khubsugul region are discussed. A scheme of the vertical zonality of soils under mountain forests is given. It is shown that soils of the uppermost forest zone are permafrost-affected. Seasonally freezing soils under forest vegetation predominate at lower heights and in the southern part of the region near the boundary with the steppe zone. The major soil combinations under different types of forest vegetation are described. The morphological, physicochemical, and chemical characteristics of widespread forest soils are given.     

Methanogen activity in relation to water table level in two boreal fens

We studied methanogen activity—measured by in vitro methane production potential and by detection of the messenger RNA (mRNA) of a functional gene—in two boreal fens under high and deep water table (WT) level conditions resulting from a rainy growing season and a dry growing season. The depth of the highest CH₄-producing layers differed between the years. In the wet year, the highest CH₄ production rate was around 20 cm below the mean WT. In the dry year, the highest rates were measured close to the peat surface, well above the mean WT. The distribution of activity in the peat profiles of the two fens appeared to be site specific. Under deep-WT conditions, CH₄ production potential was generally lower than that under high-WT conditions. Detection of the mRNA of the methanogen-specific mcrA gene indicated in situ methanogenesis in both water-saturated peat (below the WT) and unsaturated peat (above the WT). Analyses of DNA-derived and mRNA-derived methanogen community structures showed greater similarity between those two in water-saturated peat than in unsaturated peat. This suggested that favorable conditions promoted the activity of most members in methanogen communities, but unfavorable conditions showed differences between distinct community members in adaptation to adverse conditions.     

Soil mixing and genesis as affected by tree uprooting in three temperate forests

The purpose of this study was to identify general patterns of pedoturbation by tree uprooting in three different, forested landscapes and to quantify post‐disturbance pedogenesis. Specifically, our study illustrates how the effects of ‘tree‐throw’ on soils gradually become diminished over time by post‐uprooting pedogenesis. We studied soil development within 46 pit‐mounds in two regions of the Czech Republic, one on Haplic Cambisols and one on Entic Podzols. A third study site was in Michigan, USA, on Albic Podzols. Uprooting events were dated by using tree censuses, dendrochronology and radiometry. These dates provided information on several chronosequences of pedogenesis in the post‐uprooting pits and mounds, dating back to 1816 AD (dendrochronological dating, Haplic Cambisols), 322 AD (median of calibration age, ¹⁴C age = 1720 ± 35 BP, Entic Podzols) and 4077 BC (¹⁴C age = 5260 ± 30 BP, Albic Podzols). Post‐uprooting pedogenesis was most rapid in pits and slowest on mounds. Linear chronofunction models were the most applicable for pedogenesis, regardless of whether the soils were in pit or mound microsites. These models allowed us to estimate the time required for horizons in such disturbed sites to obtain the equivalent thicknesses of those in undisturbed sites. These ranged from 5 (O horizon in pits on the Haplic Cambisols) to > 16 000 years (E horizon on mounds on the Albic Podzols). On the Albic Podzols, development of eluvial and spodic horizon thicknesses suggested that pathways involving divergent pedogenesis may occur at these small and localized spatial scales.     

黑龙江省东部水源区植被土壤水源涵养功能分析

在对黑龙江省东部水源区5种不同植被土壤层的水分物理性质、蓄水性能、渗透性能以及土壤水分的动态变化进行定位观测分析基础上,对各植被土壤层的水文特征进行了综合比较。结果表明,天然林和灌丛林林地土壤水源涵养能力最强,针叶林地一般,云杉幼林地最差。加强对天然林资源的保护,提高灌丛在当地林木植被资源中的比例,加强人工针叶林林分结构的调整与抚育管理,是提高当地森林植被系统涵养水源功能的有效途径。     

晋中东山地区褐土土壤水分特征的测定与应用

利用压力膜方法测定晋中东山地区褐土的土壤水分，并分析了土壤水分及其能态特征。结果表明：本区土壤水吸力与土壤含水量之间呈明显的幂函数关系，可以用幂函数方程模拟；土壤的当量孔径分布大致随土壤水吸力的增加而减小；土壤的结构性能良好，通气孔隙、毛管孔隙、无效孔隙的当量孔径分布分别占土壤总孔隙度的１８．３％、５１．２％和３０．５％，尤其是毛管孔隙的分布占土壤总孔隙度的一半以上；土壤的比水容量随吸力的增大而迅速减小．当吸力为０．１×１０￣５～０．３×１０￣５ｐａ时，其比水容量的量级为１０￣（－１）［ｍ１／（１０￣５ｐａ·ｇ）］，而当吸力达３×１０￣５～１５×１０￣５ｐａ时，其比水容量的量级下降了１００倍，为１０￣（－３）［ｍｌ／（１０￣５Ｐａ·ｇ）］。表层土壤水分对于作物吸收利用比心土层和底土层更为有效，但深层土壤的持水性能比表层士壤要好。为此，必须提高作物对土壤深层储水的利用。     

陇东黄土高原土壤干旱特征分析

通过对黄土高原典型残塬"董志塬"麦田不同时期土壤各层次水分含量的分析,揭示了陇东黄土高原塬区土壤干旱特征,逐月分析了干旱的季节分布以及不同季节水分在土壤各层次的分布特征。分析认为2m土层干旱概率明显高于0.5m土层,但0.5m土层重旱出现概率明显偏高,各层次干旱出现频率均未超过45%。干旱的季节分布特征表现为:3月～6月土壤水分持续减少,干旱持续发展,6月上中旬是陇东麦田最干旱的时期。小麦收获后,7月分土壤水分开始回升,7月～9月为土壤水分恢复平衡阶段,10月为土壤水分恢复平衡后相对稳定阶段。收墒期降水可以使2m土层土壤水分基本恢复到适宜状态,土壤储水主要分布在2m土层,即2m为土壤水库下限深度。8月开始,麦田中下层土壤水分运动方向发生逆转,由前期的向上运动转变为向下运动。麦田涝渍现象出现在秋季,主要出现在土壤中下层。早春和晚秋麦田重旱发生概率较低,秋季是陇东麦田土壤水分含量最高的时期,晚秋2m土层平均含水量超过早春,土壤水分于秋季恢复平衡,晚秋-早春,即越冬期降水量小于土壤蒸散量,土壤水分有一定损耗。     

Soil Indicators of Paleoenvironmental Conditions in the South of the East European Plain in the Quaternary Time

Eurasian Soil Science - Climatic conditions are an important factor affecting mineralogical and chemical compositions of soils and paleosols with the formation of paleosol archives that reflect...     

我国东部河网地区土壤与河道底泥对磷的吸附特性比较研究

通过等温吸附、动力学吸附和热力学吸附模拟试验对我国东部河网地区稻田土壤与河道底泥对P的吸附特性进行了比较研究.结果表明:Langmuir方程对稻田土壤与河道底泥对P的等温吸附拟合程度最好,Freundlich方程次之,Temkin方程最差.稻田土壤和河道底泥的吸附常数K值分别为0.82和0.95,表明河道底泥吸附P的能力要强于稻田土壤.无论是稻田土壤还是河道底泥,对P的吸附都存在着快吸附和慢吸附两个过程.稻田土壤与河道底泥对水体P的吸附主要发生在0 ～ 2 h之内,2 h以后基本达到了一种慢吸附直至平衡过程.在相同的时间段内,河道底泥对P的吸附速率比稻田土壤大,Elovich方程为描述P动力吸附的最优模型.P的热力学吸附结果表明,温度对河道底泥和稻田土壤吸附P都有明显的影响,但比较而言,温度对河道底泥吸附P的影响较大,也就是说,河道底泥更容易发生对P的吸附反应.     

Soil data importance in guiding maize intensification and yield gap estimations in East Africa

Wide maize yield gaps have been reported in Eastern Africa, hence possibility for increasing production. Previous yield gap studies relied on generic soils data such as Harmonized World Soils Database (HWSD). Using CERES-Maize model, the importance of newly available and detailed Africa Soil and Information Service (AFSIS) data in estimating yield gaps and assessing intensification potentials was studied at Sidindi, Kenya and Mbinga, Tanzania. Predicted water-limited yields (Yw) at Sidindi using AFSIS and HWSD soils data were 9.21 Mg ha^?1 and 9.88 Mg ha^?1 (p = 0.002); and at Mbinga 10.48 Mg ha^?1 and 10.90 Mg ha^?1 (p = 0.085). Adequate rainfall masks differences in simulated Yw. The calibrated model predicted grain yield with a root mean square (RMSE) of 1.7 Mg ha^?1 at Sidindi; and 2.13 Mg ha^?1 at Mbinga. The model was sensitive to available phosphorus, with a 15% increase resulting in yield increases of 177% for treatment NK and 46% for the control. For stable organic carbon content, a 15% decrease increased grain yields for treatment PK by 57.6%. To guide intensification and yield gap estimations, accurate active soil carbon, total carbon, available phosphorus and texture data are vital.     

Factors influencing nitrous oxide and methane emissions from minerotrophic fens in northeast Germany

 At two field sites representing northeastern German minerotrophic fens (Rhin-Havelluch, a shallow peat site; Gumnitz, a partially drained peat site) the influence of different factors (N fertilization, groundwater table, temperature) on N₂O and CH₄ emissions was investigated. The degraded fens were sources or sinks of the radiatively active trace gases investigated. The gas fluxes measured were much higher than those found in other terrestrical ecosystems such as forests. Lowering the groundwater table increased the release of N₂O and the oxidation of CH₄. High CH₄ emission rates occurred when the groundwater tables and soil temperatures were high (>12  °C). N fertilization stimulated the release of N₂O only when application rates were very high (480 kg N ha^–1). A moderate N supply (60 or 120 kg N ha^–1) hardly increased the release of N₂O in spite of high soluble soil NO₃ ^– contents. Received: 31 October 1997     

Soil Degradation Due to Vicinal Intensive Hog Farming Operation Located in East Mediterranean

One of the main environmental impacts of concentrated animal feeding operations is the soil degradation in vicinity with the livestock breeding facilities due to substances such as ammonia emitted from the various stages of the process. Owing to the high temperatures of the Mediterranean ecosystems, the evolution of gasses is more extensive and the soil degradation is consequently more severe than those obtained in northern Europe. In this research, the soil degradation effects of a large meat-producing, processing, and packaging unit have been investigated. The investigated intensive hog farming operation (IHFO) is located at a limestone soil coastal area with sea to the north and hills to the south. Soil samples of the upper mineral soil were taken in various distances and directions from the IHFO boundaries. Thirteen experimental cycles were carried out in the duration of 1.5 years starting in March 2009 until October 2010. The soil samples were analyzed on pH and electrical conductivity (EC) values as well as NH₄ ⁺ and NO₃ ⁻ concentrations. Significantly higher concentrations of the two nitrogen forms were observed on samples at increasing proximity downwind from the farm (south). Southern soil average NH₄ ⁺ and NO₃ ⁻ concentrations ranged between 0.4–118 μg NH₄ ⁺-N g⁻¹ soil and 6.1–88.4 μg NO₃ ⁻-N g⁻¹ soil, respectively. The variation of emitted gasses depositions was clearly reflected in the average pH and EC values. Average pH and EC values downwind from IHFO boundaries varied between 7.1–8.2 and 140–268 μS/cm, respectively.     

Soil sensitivity due to acid and heavy metal deposition in East Central Europe

Simultaneous soil acidification and deposition of heavy metals is a major concern for forest and agricultural soils of the Black Triangle region of East Central Europe including southern former East Germany, northern Bohemia of the Czech Republic, and southern Poland. The objective of this project was to develop historical and future projections of acid and heavy metal deposition to soils (As, Cd, Pb, Zn) and to produce a preliminary map of soil sensitivity to cadmium pollution and uptake by crops. Ultimately, we wish to assess the relative hazard and recovery times of soils to metals deposition in the region. Emission and deposition data bases obtained from several models developed at IIASA were linked using the Geographical Information System ARC/INFO to produce soil maps of sensitivity to cadmium mobility based on metals deposition, soil type, soil texture, organic matter content, and acid deposition. RAINS 6.1 (Alcamo et al., 1990) was utilized to produce maps of acid deposition for EMEP grids (150 km x 150 km). The largest amount of acid load is deposited in southern East Germany. Sulfur deposition in that area was 10–12 gS/m²/yr in 1990, and S+N deposition exceeded 8000 eq/ha/yr. But the hot spot for metals deposition is further to the east, in the Silesia area of southern Poland. The TRACE2 trajectory model of Alcamo, Bartnicki, and Olendrzynski (1992) was used to estimate cumulative metals deposition since 1955 with scenarios to 2010. Pb has improved over Europe since 1970 when depositions in the Ruhr River Valley of West Germany exceeded 60 mg/m²/yr. But cadmium deposition in southern Poland (Katowice and Krakow) has now accumulated to 60–70 mg/m² by atmospheric deposition alone. During base case simulations from 1955–87, approximately 1.8 mg/kg Pb and 0.12 mg/kg Cd have been added to the mixed plow-layer of 30 cm. If these emissions continue indefinitely, the accumulation of metals will become problematic for agriculture and the food chain.     

Soil erosion from a single rainstorm over an area in East Lothian, Scotland

Abstract. An area of about 24 km² in arable East Lothian, Scotland, was examined for soil erosion by water following a severe rainstorm in October 1990. Significant erosion was found in only 10 fields out of 26.5 in an area where topography, soils and cropping suggest a high erosion risk. Doubt is cast on some assessments of the widespread risk of significant soil erosion by water in arable areas of the UK.     

对陇东黑垆土“古耕层”问题的商榷

陇东黑垆土存在“古耕层”的问题,曾经有过多次的争论,本文以大量的事实为根据,阐明了垆土层之上的覆盖层并非是人为的简单堆积,而是长期以来全新世至现代的沉积物。为进一步研究黑垆土类提供了充分的依据。     

中国中东部样区土壤、地形与耕地空间分布多样性特征

土壤、地形作为重要的自然因素,与耕地的关系密不可分。选取河南、江苏、浙江三省的9个典型样区作为研究对象,运用改进的仙农熵测度方法在3 km×3 km网格尺度下计算研究区的地学要素空间分布多样性特征。结果表明:(1)河南省样区的土类个数较其他地区丰富;如皋市、宁波市、诸暨市的土类具有单一性;开封市的土类空间分布特征最具波动性;多数样区土类的空间分布特征都具有相对稳定性。(2)研究区在平耕地以及浙江省的6°～15°下的缓坡耕地上地形的空间分布均匀度都在0.9以上,且耕地与地形坡度的相关强度与该特征具有相同规律。从地形类别来看,平原的空间分布特征最均匀,与耕地的相关性也最强。(3)随着时间变化,研究区耕地面积整体上呈减少趋势,但耕地的空间分布特征均匀度整体稳定。(4)在潮土和水稻土上,耕地的空间分布最均匀,且它们与耕地的关联性也相对最大,具有一致性特征。综上所述,土类和地形的空间分布特征具有复杂性,耕地的空间分布特征具有相对稳定性;研究区典型土类(如潮土、水稻土)、平耕地坡度(≤2°和2°～6°)、平原类别分别与耕地的空间分布格局具有较强的相关性。     

Burn Effects on Soil Aggregate Stability and Water Repellency of Two Soil Types from East and North Tunisia

To date, evidence of the potential effects of burning practices on soil properties in Tunisia is limited. In order to address this issue, we carried out laboratory investigations of the effects of burning on soil aggregate stability (AS) and water repellency (WR) of a clayey and a sandy loam Fluvisol soils. The treatments included low (100°C, LT), medium (300°C, MT) and high (600°C, HT), heating temperatures. Unburned (0°C, UB) soil samples were used as a control. Two breakdown mechanisms, fast wetting (FW) and mechanical breakdown (MB), were used for the measurement of AS. The latter is expressed by calculating the mean weight diameter (MWD). The water drop penetration time (WDPT) was used to evaluate the soil WR. The results showed that the unburned clayey and sandy loam soils are poorly aggregated. The HT and MT treatments significantly (p < 0.05) increased MWD of both soils, compared to UB samples, following the FW stability test. A lesser increase of MWD was observed with the MB test. The LT treatment did not significantly (p < 0.05) affect the soils AS. For the unburned clayey soil, the FW and MB tests gave significantly (p < 0.05) different MWDs . In contrast, the unburned sandy loam soil had similar MWDs under both tests. As for water repellency, the sandy loam soil was initially wettable and the clayey soil slightly water repellent. Burning treatments did not affect the sandy loam soil behavior but caused a decrease of clayey soil WR.     

不同施肥制度下冀东褐土肥力演化的主成分分析

以冀东褐土为试材,采用主成分分析方法对连续8年不同施肥制度定位试验土壤的肥力演化进行了研究。结果表明,不同施肥制度下作物产量、土壤物理性质、土壤有机碳及氮磷钾养分含量与组成、土壤酶活性等变化各异,冀东褐土肥力演化方向可用土壤养分贮备和供应过程与无机磷积累和无效化过程表征,不施肥使土壤养分贮备和供应极度匮乏;单施常量NPK化肥和增量NPK化肥造成土壤无机磷无效化过程强烈;有机肥(物)料配施化肥则可使土壤肥力向养分贮备丰富、供应水平高和快速、无机磷有效化程度较高的方向发展。     

青海省东部黄土地区土壤侵蚀的区域特征及其防治途径

青海省东部农业区即青藏高原东部边缘黄土地区是全省水土流失最严重的地区,水土流失面积约占全区总面积的50%。强度流失区和中度流失区分别占流失面积的20%和30%,其余为轻度流失区。导致土壤侵蚀发生的主导因素是大陆性气候和起伏悬殊的地形,不合理的人为活动,加剧了现代土壤侵蚀。本文通过综合分析土壤侵蚀的影响因子和形成原因,对本区土壤侵蚀分区和区域特征进行探讨,并结合各区自然条件和侵蚀特点指出了搞好水土保持的有效途径。