Paleosols of the southern coastal plain of Israel

Paleosols of the S coastal plain of Israel were studied in a characteristic sequence situated in the Ruhama badlands area. At the upper part of the sequence, there is a Loessial Arid Brown Soil (Calciorthids), characteristic of the mildly arid climate of the area. The soil has two calcic horizons and four clayey layers alternating with four calcareous layers which are beneath them. Physical, chemical, and magnetic‐susceptibility data and micromorphological evidence indicate that each clayey layer together with the calcareous layer beneath it forms a single pedogenic unit. These units are similar to modern Grumusolic soils (Xeric Paleargids or Xererthic Calciargids) that occur in the semiarid belt of the S coastal plain and develop on eolian‐dust parent material. The calcareous layers are in fact calcic horizons formed by leaching of the carbonates from the clayey layers and accumulated in the form of in situ carbonate nodules. The leaching of the carbonates is not complete; they were never completely leached in the past. This feature together with a typical brown color is also characteristic of the modern soils developed in the semiarid water regime of the area. The four superimposed paleosols represent four cycles. It is suggested that they were formed in two phases. During a dry environment, a short phase of rapid eolian‐dust accumulation prevailed, followed by a stable phase of soil development in a somewhat wetter climate. Dating by optically stimulated luminescence and previous dating by ¹⁴C in the area suggest that the upper two paleosol cycles belong to the Last Glacial period whereas the other two cycles are of an earlier age. The magnetic‐susceptibility values decrease with age and react different from temperate areas. Below the four cycles, two totally leached paleosols developed on sandy parent material occur. Both paleosols have a reversed magnetic polarity and are hence older than 780 ky BP. The upper one is a Brown Mediterranean soil, and the lower one is a Red Mediterranean soil. Thin‐section evidence suggests that they formed on terrestrial sand dunes.     

Relationship between soil geochemistry and grape composition in Tuscany (Italy)

The concentrations of 13 trace elements were determined in soils and Sangiovese grapes collected in vineyard zones of Tuscany (Italy). The purpose was to establish a correspondence among the chemical composition of grape, the geochemistry of vineyard soil and the geolithological features of cultivation zone, and determine the provenance of the grapes by means of their chemical fingerprints. Statistical analysis of Ba, Rb and Sr concentrations distinguished three classes of grapes according to the geochemical and geopedological characteristics of the soils. Grapes with the highest Sr levels grew on high‐Sr soils derived from calcareous, calcareous‐marly and marly‐clayey rocks, whereas the most elevated Rb concentrations characterized the berries cultivated on soils formed from clayey‐marly and sandy‐marly lithologies. Grapes with the highest Ba concentrations grew on soil derived from arenaceous rocks and carbonate lithologies of evaporitic origin. These findings suggested that Ba, Rb and Sr could be used as fingerprints for the chemical traceability of Sangiovese grapes.     

不同类型生态区稻-稻种植制度中钾肥效应及钾素平衡研究

研究了在丘陵生态区和洞庭湖生态区稻-稻种植制度中钾肥对水稻产量和钾肥效应及钾素平衡的影响。结果表明,在施钾量为0、112.5、150和187.5K2O kg hm-2的条件下,在丘陵生态区红黄泥田上,150K2O kg hm-2的施钾水平已达到较高的产量;洞庭湖生态区的紫潮泥田中缓效钾与速效钾含量均较高,目前施钾效应不明显。两种类型生态区土壤上施用氮肥的增产效果明显地大于施用钾肥。丘陵生态区红黄泥田上的3个施钾处理两季水稻吸收来自肥料钾的百分数比例均高于洞庭湖生态区的紫潮泥田。丘陵生态区红黄泥田上的3个施钾处理早稻钾素利用率平均为35.0%,晚稻为51.8%;洞庭湖生态区紫潮泥的3个施钾处理早稻钾素利用率平均为27.1%,晚稻为42.6%。肥料氮的利用率随钾肥施用量的增加而提高,这一趋势在晚稻上更为明显。在每季水稻施钾量为112.5、150、187.5 K2Okg hm-2的条件下,钾素平衡出现亏缺。在早稻施氮量165N kg hm-2(丘陵生态区),150N kg hm-2(洞庭湖生态区)和晚稻施氮量180N kg hm-2的条件下,两种类型生态区土壤上的氮素平衡中氮均出现盈余,且氮素盈余量随钾肥用量的增加而下降。     

Macro- and micromorphological features of genetic horizons in a solonetzic soil complex at the Dzhanybek Research Station

The comparative analysis of macro- and microfabrics of soil horizons in a trench crossing a solonetzic soil complex on a virgin plot has shown incomplete correspondence between the macro- and micromorphological features. Solonetzic and solodic horizons and features are differently manifested in different types of soils. The soils of the complex are subjected to continuous transformation dictated by the general trend of the landscape evolution in the Caspian Lowland and by the local changes related to the activity of burrowing animals and fluctuations in the groundwater level. The current trends of evolutionary changes are reflected in the soil microfabrics and salt pedofeatures, whereas more ancient processes are recorded in the properties of the clayey plasma. In the soil of the microlow, the most complete correspondence between the macro- and micromorphological features is observed. At the microlevel, the horizons of this soil resemble the humus-accumulative and metamorphic horizons of dark-colored chernozem-like soils of vast mesodepressions. A variant of the soil evolution within the solonetzic complex is discussed.     

Response of ectomycorrhizal communities to past Roman occupation in an oak forest

The impact of past Roman occupation on the composition of ectomycorrhizal (ECM) communities was analysed in 12 Roman settlements in an oak forest in Central France. At each Roman settlement, soils and ECM roots were sampled from two plots (600 m² each), one plot close to the remains of the buildings (<100 m), supposed to be impacted by ancient Roman agriculture, and the second plot 250-500 m away from the remains of the buildings, supposed to be less intensively influenced by previous cultivation. Soils were analysed and ECM fungal taxa were identified by morphotyping and sequencing the rDNA ITS region. The soil properties were significantly affected by the past Roman occupation, in terms of nutrient availability, especially for P, N and Mg. The enhancement of soil nutrient levels by past Roman land-use had significantly modified alpha diversity and species composition of ECM communities. Among the 67 determined ECM morphotypes, 40 were shared by the occupied and non-occupied plots, 17 were found only in the occupied plots and 10 only in the non-occupied plots. Six morphotypes were significantly more frequent near the antique remnants. Our study showed, for the first time, that ectomycorrhizal communities are impacted by previous Roman land-use, even after nearly two thousand years of forest state.     

Comparative mycobiotic and edaphic analyses of two neighboring soil profiles on different lithologies in Upper Galilee, Israel

Microfungal communities from two profiles of the neighboring pale rendzina and basaltic vertisoil in the Upper Galilee area, Israel, were analyzed and compared. The bedrock lithology determines the key differences in mineralogical composition of the contrasting soils on chalk and basaltic rocks. Pale rendzina on chalk is strongly calcareous while the basaltic soil profile is leached from carbonates below the 5–8 cm depth and is significantly magnetically enhanced. The soils also differ in CEC, exchangeable cations, and in microstructure. In parallel, mycobiota isolated by the soil dilution plate method (124 species) displays different patterns both in distribution along the contrasting profiles and in structure of the communities at definite depths. The basaltic mycobiota is significantly richer (87 vs. 69 species in the rendzina) being less heterogeneous and even at a 5–50 cm depth. According to all estimated mycobiotic characteristics, at 15–18 cm depth the differences between the basaltic and rendzina soils are mostly pronounced. Excellent aeration of the basaltic soil in contrast to the rendzina may account at least partly for the peak of mycobiotic differences at this depth. No single edaphic parameter is responsible for the greatest level of variations in the mycobiotic characteristics indicating that co-influence of soil biotic/abiotic factors determined distribution of microfungi throughout the profiles.     

不同母质土壤-水稻系统Cd吸收累积特征及差异

通过选取土壤有效态镉(Cd)含量相近、母质不同的水稻土河沙泥(河流冲积物发育)和紫泥田(紫色砂页岩母质发育),添加不同浓度的外源Cd(0,0.5,1,2,5mg/kg)模拟Cd污染稻田土壤进行盆栽试验,研究不同母质稻田土壤Cd胁迫条件下水稻不同生育期对Cd吸收累积的差异,并推算出土壤Cd环境安全临界值。结果表明,水稻生育期2种土壤有效态Cd含量均在分蘖期最高,河沙泥有效态Cd含量平均为0.47mg/kg,紫泥田平均为0.36mg/kg,同一外源Cd水平下,河沙泥土壤有效态Cd含量高于紫泥田。对河沙泥而言,随着外源Cd浓度的增加,水稻总生物量呈现先增加后下降的趋势,当外源Cd浓度为1mg/kg时达到最大生物量,为47.11g/pot;而紫泥田水稻生物量呈现逐渐增加的趋势,但各处理间差异不显著(P0.05)。2种土壤中水稻糙米、谷壳、茎叶、根Cd含量均随外源Cd浓度的增加而增加,整体分布特征为根茎叶谷壳糙米,且河沙泥高于紫泥田;河沙泥水稻平均Cd累积量为51.71μg/pot,紫泥田平均Cd累积量为42.56μg/pot,2种土壤成熟期水稻Cd累积量对比分蘖期分别增加1.45,1.07倍。回归分析表明,河沙泥和紫泥田稻米Cd超标的土壤Cd安全临界值分别为2.03,3.14mg/kg。水稻对Cd的吸收累积特征及土壤Cd安全临界值因土壤母质不同而存在显著差异。     

几种稻田土壤对铵的矿物固定的动力学与热力学研究

本文采用振荡平衡法研究了紫泥田、河沙泥、灰泥田及红黄泥4种稻田土壤对铵的矿物固定的动力学及热力学特性。结果表明,供试土壤对添加铵的矿物固定速度很快,随着固铵量增多,固铵速度下降,反应后24小时固定基本上达到平衡,不因土壤种类而异。数学拟合结果表明,以一级动力学方程和E lovich方程描述供试土壤对铵的矿物固定资料最优,抛物扩散方程也能较满意地描述实验结果,以零级方程的拟合效果最差。供试土壤对铵的矿物固定的热力学资料均能用一元Langmu ir吸附等温式、Freund lich吸附等温式和Temk in吸附等温式拟合,拟合结果均达极显著水平,但以一元Langmu ir吸附等温式的拟合结果最优,由一元Langmu ir吸附等温式可以求得土壤对铵的矿物固定的热力学平衡常数、最大固铵量以及固铵过程中的自由能变△G°。供试土壤固铵过程的自由能变△G°均为负值,说明供试土壤对铵的矿物固定为一自发过程,4种土壤固铵强度依次为紫泥田>河沙泥>灰泥田>红黄泥。     

喀斯特山区不同母质(岩)发育的土壤主要理化性质差异性分析

在贵阳市乌当区采集了白云岩、石灰岩、钙质紫色砂页岩等9种母质(岩)上发育的土壤样品763个,分别进行了土壤主要理化性质的测定和差异性分析。结果表明不同母质(岩)发育的土壤理化性质具有很大的差异:红色粘土、老风化壳和页岩上发育的土壤pH值均为酸性至强酸性,有机质和CEC含量中等,土壤质地较粘重;石灰岩、白云岩和钙质紫色砂页岩上发育的土壤pH值为中性至微碱性,有机质和CEC含量较高,质地较为适中;砂页岩和河流冲积物上发育的土壤pH值为酸性至中性,其余理化性质为中等水平;砂岩发育的土壤pH值为强酸性,其余理化性质均较差。     

Soil micromorphological and physical properties after application of composts with polyethylene and biocomponent-derived polymers added during composting

Composts are considered to be one of the best soil amendments. However, the effects of composts with added polymeric materials on soil physical,hydraulic, and micromorphological properties have not been widely discussed. Changes in soil physical properties influence the numerous services that soils provide. We studied the impacts of composts with the addition of three different polymers(F1–F3) produced from polyethylene and thermoplastic corn starch on the physical, hydraulic, and micromorphological properties of two soils, a Cambic Phaeozem and a Luvic Phaeozem. Applying composts with polymers had limited or no significant effect on soil bulk density and porosity, but increased the field water capacity by 18%–82% and 3%–6% and the plant-available water content by 15%–23% and 4%–17% for the Cambic Phaeozem and Luvic Phaeozem, respectively. The application of composts with polymers had a greater effect on the Cambic Phaeozem than on the Luvic Phaeozem. It was suggested that the use of modified composts led to changes in soil physical properties and micromorphological features and this effect was dependent on the compost application rate. Composts made with the addition of composite synthetic and natural material-derived polymers during composting were found to be a composite mixture that can be successfully used in agriculture.     

DCD 在不同质地土壤上的硝化抑制效果和剂量效应研究

通过硝化抑制剂抑制土壤硝化作用是实现作物铵硝混合营养和提高氮肥利用率的重要途径之一。本试验采用室内模拟的方法, 在人工气候室(25 ℃)黑暗培养条件下, 应用新疆石灰性土壤研究了不同剂量的双氰胺(dicyandiamide, DCD)在砂土、壤土、黏土3 种不同质地土壤中对土壤硝态氮、铵态氮转化的影响及DCD 的剂量效应和硝化抑制效果。处理30 d 内, 各剂量DCD 处理对砂土的硝化抑制率为96.5%~99.4%(平均值为98.3%), 在黏土上为66.9%~85.6%(平均值为77.6%), 在壤土上为49.3%~79.4%(平均值为67.7%), 总体硝化抑制率表现为砂土>黏土>壤土。在砂土上DCD 的剂量效应不明显, DCD 用量从纯氮的1.0%增加到7.0%时, 土壤中硝态氮含量仅增加1.9~10.7 mg·kg^-1(培养30 d 时); 而在壤土和黏土中, 土壤硝态氮含量随DCD 浓度的增加而显著下降, 存在明显剂量效应。这说明施用DCD 可显著抑制新疆石灰性土壤的硝化作用过程, 在砂土、壤土、黏土中DCD 的最佳浓度分别为纯氮用量的6.0%、7.0%和7.0%, 并在培养30 d 内发挥显著作用。     

贵阳市乌当区不同母质发育的土壤理化性质和重金属含量差异研究

在贵阳市乌当区采集了9种母质（岩）上发育的土壤样品763个，分别测定了土壤的主要理化性质和主要重金属元素含量，通过对比分析表明不同母质（岩）发育的土壤理化性质和重金属含量都具有很大的差异。土壤理化性质的差异性主要表现为：石灰岩、红色粘土、老风化壳和页岩发育的土壤质地粘重。砂岩发育的土壤质地较轻，钙质紫色砂页岩、白云岩、砂页岩和河流冲积物发育的土壤质地适中；石灰岩、白云岩和钙质紫色砂页岩发育的土壤pH值为中性至微碱性。河流冲积物发育的土壤pH值为中性，其余5种母质（岩）发育的土壤pH值为酸性至强酸性；白云岩、钙质紫色砂页岩和河流冲积物发育的土壤有机质含量较高，而砂岩发育的土壤有机质含量较低，其余5种母质（岩）发育的土壤有机质含量介于二者之间；河流冲积物、石灰岩、白云岩和钙质紫色砂页岩等发育的土壤CEC较高，而砂岩发育的土壤CEC较低，其余4种母质（岩）发育的土壤CEC介于它们之间。土壤重金属含量差异性表现为：钙质紫色砂页岩、石灰岩、河流冲积物等发育的土壤中锅、铬、汞的含量较高。而红色粘土、河流冲积物和石灰岩等发育的土壤中铅和砷含量较高，砂岩发育的土壤中5种重金属元素的含量均为最低，其余母质（岩）发育的土壤中5种重金属元素的含量均介于上述之间。通过相关性分析结果表明：研究区域内土壤重金属镉、铬、汞、铅、砷的含量差异主要是由于成土母质（岩）的差异性所致，土壤理化性质的变化则是影响土壤重金属含量的次要因素。     

Polygenesis of volcanic paleosols in Armenia and Mexico: Micromorphological records of climate variations in the quaternary period

The Pleistocene volcanic paleosols of Armenia and Mexico combine the features of both arid and humid pedogeneses. They were studied in order to reconstruct the environmental conditions during the period of the initial settlement of humans in these areas. The main attention was paid to the micromorphological analysis of the pedogenic features. The pedocomplexes studied in Armenia have been forming since the Early Pleistocene. They bear evidences of humid (weathering, clay illuviation, and gleying) and arid (calcification) pedogeneses alternating in different soil layers and pointing to climatic cycles. The nonuniform lithology of the soil profiles is related to pulsating volcanic activity. Mexican paleosols of the Late Pleistocene period are similar to the lower layers of the soils in Armenia with respect to the features characteristic of the humid and arid phases of pedogenesis. This allows us to suggest that the early stages of the formation of the Armenian pedocomplex proceeded under warmer paleoclimatic conditions similar to those of a tropical climate. It is shown that the arid pedogenesis may erase the features produced during the previous stage of humid pedogenesis. The studied paleosols are characterized by the destruction of the features inherited from the humid phase (the clayey groundmass and illuviation coatings) by the newly forming calcite. Paleopedological records point to the fact that the paleoenvironmental conditions during the periods of the initial settlement of humans in both regions differed significantly from the modern environmental conditions in these regions.     

Effect of humic acid on growth and crop nutrient status of wheat on two different soils

The effect of plant-derived humic acid (PDHA) and coal-derived humic acid (CDHA) on wheat growth was tested on two alkaline calcareous soils in pots. Humic acid derived from plant and coal materials was applied at the rate 0 (control), 50 and 100 kg/ha to wheat in pots carrying two soils viz. clayey loam soil and sandy loam soil separately. Data was collected on plant growth parameters such as spike weight, grain and straw weight, and plant nutrients (macronutrients and micronutrients). Results showed that spike weight increased by 19%, 15%, and 26%, and 11% with application of PDHA at the rate of 50 and 100 mg/kg in clayey loam and sandy loam soil, respectively. Grain yield show an increase of 21% and 11% over control with application of PDHA and CDHA at the rate of 50 mg/kg on both soils, respectively, and 10% and 22% with application of PDHA and CDHA at the rate of 100 mg/kg on both soils.     

The base saturation in acidified Swiss forest soils on calcareous and noncalcareous parent material. A pH–base saturation anomaly

Long‐term soil acidification leads to lower pH values and to a concomitant decrease in base saturation (BS). The relationship between pH and base saturation (BS) in acidified forest soils can be disturbed by processes such as nutrient cycling by vegetation, temporary saturation by ground water that comes into contact with calcareous material, or by upward diffusion of base cations from deeper horizons. This paper examines the relationship between pH and BS in Swiss forest soils developed from calcareous and noncalcareous parent material and identifies some of the factors that can affect the BS in the decalcified parts of soils derived from calcareous parent material. The decalcified zone in the latter soils has a higher BS on average compared to soils from noncalcareous parent material, but their pH values are identical. In the pH range 4.0–4.5, the difference in BS may vary by a factor of three. The mean BS in the decalcified zone tends to decrease with increasing depth of the calcareous layer. The water regime also affects the BS in soils on calcareous parent material. In soils temporarily saturated by groundwater (gleysols), the BS in the decalcified zone is always high (85%–100%) because of the continuous contact between the soil water and the calcareous parent material. In addition, the inhibited drainage impedes the depletion of base cations in these soils. In contrast, soils that are temporarily saturated by rainwater are depleted in base cations due to the alternating wetting‐and‐drying regime and the associated leaching of dissolved ions. In such soils, the depletion of base cations is strongly related to the extent of hydromorphy. Stagnogleyic soils, with the longest period of water saturation, have the highest depletion levels. We conclude that in such soils, the diffusion of base cations from deeper zones is strongly compensated by leaching from the very acidic soil horizons. The pH–base saturation anomaly has consequences for some of the methods used to calculate the critical loads of acidity for forest soils in Switzerland, with many soils being less sensitive than previously reported.     

不同形态磷酸盐及施用方式对石灰性土壤磷移动性和有效性的影响

  【目的】  磷的固定是石灰性土壤中磷肥效益低的重要原因,研究两种施肥方式下不同形态磷源在石灰性土壤中的迁移以及有效性,为实现磷肥减施增效提供理论基础。  【方法】  采用土柱模拟试验方法进行研究,供试土壤为粘质和壤质石灰性土壤。供试磷酸盐为磷酸脲、焦磷酸和聚磷酸,壤土施磷量为0.0581 g/柱,粘土为0.0594 g/柱。施用方式包括一次施用和分4次滴施,同时以不施用磷酸盐土柱为对照。于地下室内 (27 ± 1.0)℃培养28天后将土柱在?80℃条件下快速冷冻固形,从土表向下0—100 mm内每隔5 mm作为一个切割单元,100—300 mm间每隔20 mm作为一个切割单元,测定每层土壤的水溶性磷和Olsen-P含量。  【结果】  培养28天后,一次施用条件下,磷在壤土中的移动距离表现为聚磷酸 (90 mm) > 焦磷酸 (60 mm) > 磷酸脲 (50 mm),粘土中表现为聚磷酸 (80 mm) > 焦磷酸 (70 mm) > 磷酸脲 (60 mm)。分次滴施条件下,聚磷酸 (95 mm) 在壤土中的移动距离比磷酸脲 (65 mm) 和焦磷酸 (70 mm) 分别增加46.2%和35.7%,在粘土中聚磷酸 (90 mm) 的移动距离较磷酸脲 (70 mm) 和焦磷酸 (75 mm) 分别增加28.6%和20.0%。磷浓度下降到一半时所达到土柱深度 (半运移深度) 的结果表明,在壤土一次施用条件下,半运移深度表现为聚磷酸 (15.1 mm) > 焦磷酸 (11.4 mm) > 磷酸脲 (10.5 mm),分次滴施条件下半运移深度为聚磷酸 (20.0 mm) > 焦磷酸 (14.4 mm) > 磷酸脲 (14.3 mm)。在粘土一次施用条件下,半运移深度为聚磷酸 (17.7 mm) > 焦磷酸 (15.8 mm) > 磷酸脲 (14.8 mm),分次滴施条件下,聚磷酸、焦磷酸和磷酸脲的半运移深度依次为51.3、27.1和41.4 mm。相关性分析结果表明,不论一次施用还是分次滴施,聚磷酸和焦磷酸处理均随着水溶性磷含量的增加,有效磷含量在粘土上的增加量大于在壤土上的,分次滴施聚磷酸较一次施用在同样水溶性磷含量下,有效磷的含量在粘土和壤土中的差距减小,焦磷酸处理中水溶性磷与有效磷在两种土壤上较为接近。磷酸脲一次施用后,有效磷在粘土中随水溶性磷的变化量大于在壤土中,分次滴施结果则相反。  【结论】  在质地为壤土和粘土的石灰性土壤中,不论是一次性施用还是分次滴施,磷的移动性均表现为聚磷酸 > 焦磷酸 > 磷酸脲,且分次滴施3种磷源时磷的移动性和有效性均显著高于一次施用。同样水溶性磷含量条件下,粘土中磷的有效性高于壤土,分次滴施提高土壤磷素有效性的效果表现为粘土优于壤土。     

黄河流域土壤研究——Ⅱ.华北平原土壤的发生和演变

华北平原的土壤过去尚无系统的研究。侯光炯等^[1]在河北省定期会进行土壤详测,将土壤划分为石灰性棕色土、镬土及冲积土等。     

Comparative micromorphology of some soil types of Lower Egypt

A comparative micromorphological study was carried out on typical profiles of six soil types that represent major soil regions of Lower Egypt. The macro- and micromorphology of each soil profile is described and the main physical and chemical data are given. The mode of occurrence and organization patterns of the fabric elements (plasma, skeleton grains, and voids) and units (s-matrix, pedological features, and peds) are systematically discussed at the different fabric levels (plasmic fabric, plasma-skeleton grains fabric and basic, elementary, primary, and secondary structure). It was found that most of the soil profiles were apedal. The main pedological features were sesquioxidic and/or carbonate nodules and gypsic crystallaria. The plasmic fabric, in general, was argillasepic but was vo-or skel-masepic in the clayey soil types. The plasma-skeleton grains fabric was mainly porphyroskelic. The basic structure included vughy and planar types, and the elementary and primary structures included glaebular, crystallaric and subcutanic types. Only the heavy clayey horizons showed secondary structures such as platy to subrounded blocky peds. Micromorphological features are discussed in relation to soil-forming processes.     

湖南省几种稻田土壤微生物区系的研究

对湖南省3个国家水稻工程基地的7种水稻土微生物区系的分析结果表明,7种水稻土中3类微生物总数依次为黄沙泥>紫沙泥>河沙泥>紫泥田>红黄泥>潮沙泥>黄泥田,特殊生理群的微生物数量也以河沙泥和紫沙泥等通气性好、质地好的土壤中最多,而黄泥田和红黄泥等紧实土壤中微生物数量较少。农业生产中要因土壤类型采取相应的农业技术措施。