Morphology and properties of the soils of permafrost peatlands in the southeast of the Bol’shezemel’skaya tundra

The morphology and properties of the soils of permafrost peatlands in the southeast of the Bol’shezemel’skaya tundra are characterized. The soils developing in the areas of barren peat circles differ from oligotrophic permafrost-affected peat soils (Cryic Histosols) of vegetated peat mounds in a number of morphological and physicochemical parameters. The soils of barren circles are characterized by the wellstructured surface horizons, relatively low exchangeable acidity, and higher rates of decomposition and humification of organic matter. It is shown that the development of barren peat circles on tops of peat mounds is favored by the activation of erosional and cryogenic processes in the topsoil. The role of winter wind erosion in the destruction of the upper peat and litter horizons is demonstrated. A comparative analysis of the temperature regime of soils of vegetated peat mounds and barren peat circles is presented. The soil–geocryological complex of peat mounds is a system consisting of three major layers: seasonally thawing layer–upper permafrost–underlying permafrost. The upper permafrost horizons of peat mounds at the depth of 50–90 cm are morphologically similar to the underlying permafrost. However, these layers differ in their physicochemical properties, especially in the composition and properties of their organic matter.     

Bioavailability of zinc and lead from a contaminated soil amended with pine bark-goat manure compost

The distribution in soil and plant uptake of zinc (Zn) and lead (Pb) as influenced by pine bark-goat manure (PBG) compost additions were investigated from the soils artificially contaminated with Zn or Pb ions using maize (Zea mays L.) as a test crop. Soils were amended with four rates of pine bark-goat manure compost (0, 50, 100, and 200 tons ha^?1) and four rates (0, 300, 600 and 1200 mg kg^?1) of Zn or Pb. Maize was planted and grown for 42 days. At harvest, plants samples were analyzed for Zn and Pb concentration. Soils samples were analyzed for pH, extractable and diethylene triamine pentaacetic acid (DTPA) extractable Zn and Pb. Extractable Zn and Pb was lower in PBG compost amended soils than in unamended soils and steadily declined with increasing amount of compost applied. The extractable fraction for Zn dropped by 62.2, 65.0 and 44.6% for 300, 600 and 1200 mg Zn kg^?1, respectively when 200 t ha^?1 of PBG compost was applied. Metal uptake by maize plants were directly related to the rate of applied heavy metal ions with greater concentrations of metals ions found where metal ions were added to non-amended soils.     

Nodulation and root growth increase in lower soil layers of water‐limited faba bean intercropped with wheat

Below‐ground niche complementarity in legume–cereal intercrops may improve resource use efficiency and root adaptability to environmental constraints. However, the effect of water limitation on legume rooting and nodulation patterns in intercropping is poorly understood. To advance our knowledge of mechanisms involved in water‐limitation response, faba bean (Vicia faba L.) and wheat (Triticum aestivum L.) were grown as mono‐ and intercrops in soil‐filled plexiglass rhizoboxes under water sufficiency (80% of water‐holding capacity) and water limitation (30% of water‐holding capacity). We examined whether intercropping facilitates below‐ground niche complementarity under water limitation via interspecific root stratification coupled with modified nodulation patterns. While no significant treatment effects were measured in intercropped wheat growth parameters, water limitation induced a decrease in shoot and root biomass of monocropped wheat. Likewise, shoot biomass and height, and root length of monocropped faba bean significantly decreased under water limitation. Conversely, water limitation stimulated root biomass of intercropped faba bean in the lower soil layer (15–30 cm soil depth). Similarly, total nodule number of faba bean roots as well as nodule number in the lower soil layer increased under intercropping regardless of water availability. Under water limitation, intercropping also led to a significant increased nodule biomass (48%) in the lower soil layer as compared to monocropping. The enhanced nodulation in the lower soil layer and the associated increase in root and shoot growth provides evidence for a shift in niche occupancy when intercropped with wheat, which improves water‐limited faba bean performance.     

仿海豚皮肤结构的功能表面提高离心泵效率

为了提供一种可利用仿生功能表面提高泵类产品效率的方法,该文分别以鲨鱼皮肤及海豚皮肤表面结构为模仿原型,设计了2种仿生功能表面,模仿鲨鱼皮肤结构的功能表面为模型1,仿海豚皮肤结构的功能表面为模型2,并以吉林市奥吉通泵业有限公司生产的200QJ50-26离心式水泵为载体,进行了试验研究。研究结果表明,模型1可提高水泵效率2%~3%,模型2可提高水泵效率5%,且模型2在全流段范围内增效效果显著。利用氢气泡流动显示试验,从流场尾迹再附点及涡距2个方面说明了上述2种模型对流体介质的控制机制。试验结果表明,模型2相比模型1,其尾迹再附点距离降低5 mm,而尾迹涡距距离却增加3 mm。说明模型2的压差阻力得到降低,此外,模型2通过降低涡生成密度及速度的方式降低能量的耗散,其减阻效果更明显。该研究为仿生功能表面在以流体为工作介质的流体机械及在流体介质中运行的交通工具的全面应用提供了参考。     

协助自然修复微量元素污染酸性土壤研究：8年田间试验

There are many remediation techniques for organic contaminated soils,but relatively few of them are applicable to trace elementcontaminated soils.A field experiment was carried out to investigate assisted natural remediation（ANR） of an acid soil contaminated by As,Cd,Cu,Zn and Pb using one inorganic amendment,sugar beet lime（SL）,and two organic amendments,biosolid compost（BC）and leonardeite（LE）.The experiment was arranged in a completely randomized block design with four treatments in three replicates:1) a non-amended control（NA）;2) SL amended at 30 Mg ha^-1 year^-1;3) BC amended at 30 Mg ha^-1 year^-1 and 4) LE amended at 20 Mg ha^-1 year^-1 plus SL amended at 10 Mg ha^-1 year^-1（LESL）.The amended plots received two doses of each amendment（DO2）:one in October 2002 and another in October 2003.The plots were then divided in half into two subpolts and one subplot received another two doses of the same amendments（DO4） in October 2005 and October 2006.In 2011,the pH values of the amended soils were greater than that of the NA soil,with the SL-amended soil showing the highest pH.Total organic carbon（TOC） was also greater in the amended soil,and greater with DO4 than with DO2.Amendments reduced the concentrations of 0.01 mol L^-1 CaCl₂-extractable Cd,Cu and Zn,especially in the SL-amended soil.Plant cover of colonizing vegetation was enhanced by amendments,but was independent of amendment doses.Changes in soil properties from 2003 to 2011 showed that the first amendment application of DO2 caused a high differentiation between all the amendment treatments and the NA treatment.After the second application of DO2,soil pH and TOC continued increasing slowly.Further two applications of amendments（DO4） caused differences only in the organic treatments.Plant cover increased over time in all the treatments including NA.It could be concluded that the slow and steady natural remediation of this soil could be enhanced by amendment application（ANR）.     

土壤中施加锌对豌豆(Pisum sativum L.)中锌浓度以及其种子产量的影响

A 2-year field experiment was conducted to assess the effect of applied zinc（Zn） on the seed yield of pea（Pisum sativum L.） and to determine the internal Zn requirement of pea with emphasis on the seed and leaves as index tissues.The experiment was carried out at two different locations（Talagang,Chakwal district and National Agricultural Research Centre（NARC）,Islamabad） in the Potohar Plateau,Pakistan by growing three pea cultivars（Green feast,Climax,and Meteor）.The soils were fertilized with 0,2,4,8,and 16 kg Zn ha^-1 along with recommended basal fertilization of nitrogen（N）,phosphorus（P）,potassium（K）,and boron（B）.Zinc application increased seed yield significantly for all the three cultivars.Maximum increase in the pea seed yield（2-year mean） was21%and 15%for Green feast,28%and 21%for Climax,and 34%and 26%for Meteor at Talagang and NARC,respectively.In all cultivars,Zn concentrations in leaves and seed increased to varying extents as a result of Zn application.Fertiliser Zn requirement for near-maximum seed yield varied from 3.2 to 5.3 kg ha^-1 for different cultivars.Zinc concentrations of leaves and seeds appeared to be a good indicator of soil Zn availability.The critical Zn concentration range sufficient for 95%maximum yield（internal Zn requirement）was 42-53 mg kg^-1 in the pea leaves and 45-60 mg kg^-1 in the seeds of the three pea cultivars studied.     

Land Use and Soil Organic Carbon in China’s Village Landscapes

Village landscapes, which integrate small-scale agriculture with housing, forestry, and a host of other land use practices, cover more than 2 million square kilometers across China. Village lands tend to be managed at very fine spatial scales (≤ 30 m), with managers both adapting their practices to existing variation in soils and terrain (e.g., fertile plains vs. infertile slopes) and also altering soil fertility and even terrain by terracing, irrigation, fertilizing, and other land use practices. Relationships between fine-scale land management patterns and soil organic carbon (SOC) in the top 30 cm of village soils were studied by sampling soils within fine-scale landscape features using a regionally weighted landscape sampling design across five environmentally distinct sites in China. SOC stocks across China’s village regions (5 Pg C in the top 30 cm of 2 × 10 6 km 2 ) represent roughly 4% of the total SOC stocks in global croplands. Although macroclimate varied from temperate to tropical in this study, SOC density did not vary significantly with climate, though it was negatively correlated with regional mean elevation. The highest SOC densities within landscapes were found in agricultural lands, especially paddy, the lowest SOC densities were found in nonproductive lands, and forest lands tended toward moderate SOC densities. Due to the high SOC densities of agricultural lands and their predominance in village landscapes, most village SOC was found in agricultural land, except in the tropical hilly region, where forestry accounted for about 45% of the SOC stocks. A surprisingly large portion of village SOC was associated with built structures and with the disturbed lands surrounding these structures, ranging from 18% in the North China Plain to about 9% in the tropical hilly region. These results confirmed that local land use practices, combined with local and regional variation in terrain, were associated with most of the SOC variation within and across China’s village landscapes and may be an important cause of regional variation in SOC.     

Calculating the contact area of trailer tyres in the field

The spectacular increase in the weight of self-propelled harvesters since the early 1980s also applies to trailed implements such as slurry spreaders, compost spreaders, cutter-blowers and general farm trailers. With axle loads exceeding 10 tonnes/axle (tandem 20 tonnes, tridem 27 tonnes), risks of severe compaction can now be expected, not only in field crops but also in grassland. Calculation tables for accurately evaluating contact surfaces of transport tyre, given their properties, load and inflation pressure, are insufficient at the present time. Equations for traction tyres are not suitable for trailer tyres.To overcome this deficiency, contact areas in the field were recorded on 19 sites, from soft to hard surfaces, using 24 different trailer tyres, with varying loads and inflation pressures. The regression calculations for evaluating the contact area apply to a total of 143 measurements.The dimensions of the tyre (width × unladen diameter), the load on the wheel and the inflation pressure are all highly significant variables for evaluation of the soil contact area. Considering the average residual standard deviation for each regression calculation, the best approximations are achieved by taking into account the tyre structure (cross-ply and radial), the width of tyre for cross-ply tyres and the type of tyre, in the case of a radial tyres (low profile or terra profile).Moreover, contrary to expectations, observations show that with low levels of load, reducing inflation pressure can also reduce the contact area.As regards soil hardness, observations show that there is no direct link between a hard soil and a reduced contact area; this relationship does not appear to be linear. The calculations are considered to be reliable on semi-firm to firm soil, frequently found on temporary grassland or natural grassland (penetration resistance 6.5–25.0 MPa).     

Esterification and hydrolytic activities of Candida rugosa lipase isoform 1 (LIP1) immobilized on celite 545, duolite A7, and sephadex G-25

The esterification and hydrolytic activities of free and immobilized Candida rugosa lipase isoform 1 (LIP1) were investigated. Esterification activity was determined by reacting caprylic acid with glycerol in the presence of molecular sieves (30%, w/w), and the volume of 1.0 M NaOH consumed by the reaction products upon titration was used to calculate esterification activity. Caprylic acid was also reacted with cottonseed oil, and the amount of caprylic acid incorporated after 12 h of reaction was determined. Results indicated that LIP1 had little esterification activity, which was not significantly improved upon immobilization. Hydrolytic activity was determined by incubating tricaprylin emulsion (15%, w/w) with the respective lipases for 60 min, and the reaction products were titrated against 0.5 M NaOH. LIP1 showed hydrolytic activity comparable to Lipozyme RM IM. The hydrolytic activity improved significantly upon immobilization. Immobilization on Celite 545 produced the highest increase in hydrolytic activity.     

Evaluation of the sorption process for imidacloprid and diuron in eight agricultural soils from southern Europe using various kinetic models

Kinetic studies are of great concern for understanding the processes and parameters involved in the sorption of pollutants by soils. Sorption kinetics of imidacloprid and diuron in eight soils of different characteristics, with very low organic carbon content were investigated. Pseudosecond-order kinetic reactions closely correlate with the experimental kinetic (R(2) > 0.98) in all soils. The sorbed amount of diuron was higher than that for imidacloprid. The low OC content of these soils correlated neither with the sorbed amount nor with the kinetic parameters for both pesticides. Imidacloprid sorption was correlated with silt and sand content and cation exchange capacity (CEC); meanwhile for diuron, no correlation was found. Thus, sorption kinetics take place throughout different mechanisms related mainly to the chemical character of the pesticides. Sorption kinetic parameters determined using three of the four models selected (pseudosecond-order kinetic reactions, Elovich equation, and Weber-Morris models) have been shown to be worthy to distinguish the process controlling the sorption kinetic of both pesticides.