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Eurasian Soil Science - Soil formation on the human time scale is immensely time consuming, although it can be significantly accelerated through the effects of vegetation. The content of... 相似文献
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Endla Reintam Kersti Vennik Liia Kukk Siiri Kade Kadri Krebstein Mihkel Are 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2016,66(8):698-705
ABSTRACTThe main cause of loss of soil structural stability is vehicle operation on unpaved wet surfaces. Unfortunately, there is a lack of continuous soil moisture data in predicting trafficable conditions. To measure changes in soil moisture conditions in real time, Percostation (Adek) sensors were installed in sandy loam Stagnosol soil at different depths. Problems with soil trafficability can be expected at the plastic limit, and the soil is unable to support vehicle operations at the liquid limit in such soils. The maximum water-holding capacity of the soil is 32%, the field capacity is 25%, the plastic limit is 22%, and the liquid limit is 30%. With rainfall of more than 10?mm d?1, the moisture content reached the plastic limit in the upper 25?cm of soil. The average increase in the soil moisture content after more than 10?mm of rain was 1–2.5% in a time frame of 2–3 hours. After rain, the previous soil moisture level was obtained within 2 to 3 days in the vegetation period. Measurements also allowed soil water balance and evapotranspiration modelling data to predict soil moisture conditions with an accuracy of one day but failed to predict in a shorter period. 相似文献
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The Kids Are AllRight 《百姓》2011,(6)
你是否想象过,如果自己的家出现在大银幕上,会是什么模样?杰西卡·弗莱舍曼的家作为电影《孩子们都很好》的拍摄场地,不仅通过大银幕供人们参观,还因该片获得多项奥斯卡提名而得到了更多关注。 相似文献
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Are Folkestad Jens Petter Wold Kjell-Arne Rrvik Jon Tschudi Karl Henrik Haugholt Kari Kolstad Turid Mrkre 《Aquaculture (Amsterdam, Netherlands)》2008,280(1-4):129-135
The aim of this study was to non-invasively determine fat and pigment concentrations in salmon muscle based on visible and near infrared (VIS/NIR) spectroscopy measurements of live/whole fish and fillets, and by means of digital photography (DP) of fillets. The fish used were two populations of farmed Atlantic salmon (Salmo salar L.) consisting of 46 salmon averaging 0.7 kg (range 0.17–1.7 kg, Group S) and 30 salmon averaging 2.3 kg (range 1.4–4.1 kg, Group L). Chemical analyses (fat and pigment content) and computerized tomography, CT (fat content) were used as reference methods. Group L was analysed in the live state (VIS/NIR), after gutting (VIS/NIR and CT), and as fillets (VIS/NIR and DP). Group S was analysed in the gutted state (VIS/NIR) and as fillets (VIS/NIR and DP). VIS spectroscopy predictions of pigment in whole salmon from Group S were obtained with a root mean square error of prediction (RMSEP) of 0.9 mg kg− 1 astaxanthin, and a correlation between VIS spectroscopy predicted and chemically measured pigment of r = 0.85 (p < 0.0001). The fat concentration was determined by the NIR spectroscopy in live fish with RMSEP = 1.0 fat% unit, and a correlation with chemical reference values of r = 0.94 (p < 0.0001). Fat predictions from NIR spectroscopy correlated also well with predictions from CT analyses, r = 0.95 (p < 0.0001). VIS spectroscopy and DP were equally well suited to determine pigment concentrations in salmon fillets, with prediction errors of only 0.4 mg kg− 1 astaxanthin, and a correlation with chemically determined pigment of r = 0.92 (p < 0.0001). The results obtained in the present study are the first to demonstrate successful non-invasive pigment predictions in whole salmon using VIS/NIR spectroscopy, and the possibility for simultaneous, rapid and non-destructive quantification of fat and pigment concentrations. 相似文献
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Liina Talgre Enn Lauringson Hugo Roostalu Alar Astover Viacheslav Eremeev Are Selge 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(1):70-76
Abstract A field experiment was conducted in 2004–2006 to investigate the effect of green manure treatments on the yield of oats and spring barley. In the experiment, different green manure crops with undersowing and pure sowing were compared for amounts of N, C, and organic matter driven into soil and their effect on cereal yield. The spring barley field had a total of 41.7–62.4 kg N ha?1 and 1.75–2.81 Mg C ha?1 added to the soil with straw, weed, and roots, depending on the level of fertilisation; with red clover, and both common and hybrid lucerne undersowing, with barley straw and roots, the values were 3.45–3.96 Mg C ha?1 and 139.9–184.9 kg N ha?1. Pure sowings of these three leguminous green manure crops had total applications of 3.37–4.14 Mg C ha?1 and 219.7–236.8 kg N ha?1. The mixed and pure sowing of bird's-foot trefoil provided considerably less nitrogen and carbon to the soil with the biomass than with the other leguminous crops. Application of biomass with a high C/N ratio reduced the yield of the succeeding spring cereals. Of the green manures, the most effective were red clover and both common and hybrid lucerne, either as undersowing or as pure sowing. Undersowings with barley significantly increased the N supply for the succeeding crop without yield loss of the main crop compared with the unfertilised variant. Compared with ploughing-in of green manure in autumn, spring ploughing gave a 0.2–0.57 Mg ha?1 larger grain yield. 相似文献
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Siv Kristin Prestegard Svein Rune Erga Pia Steinrücken Svein Are Mj?s Gjert Knutsen Jens Rohloff 《Marine drugs》2016,14(1)
We have searched for special characteristics in growth, protein expression, fatty acids and volatile organic compounds (VOCs) in a local Phaeodactylum tricornutum Bohlin strain (Bergen Marine Biobank), by comparing it with a common accession strain (CCAP). Differences in growth and expressed proteins were detected between the BMB strain and the CCAP strain, and the BMB strain reached the highest cell densities under the given growth conditions. Fatty acid (FA) analyses showed highest relative eicosapentaenoic acid (EPA) levels in the exponential phase (25.73% and 28.31%), and highest levels of palmitoleic acid (16:1 n-7) in the stationary phase (46.36% and 43.66%) in the BMB and CCAP strain, respectively. The most striking finding of the VOCs analyses was the relatively high levels of ectocarpene, 6-((1E)-butenyl)-1,4-cycloheptadiene, hormosirene, and desmarestene and structurally related compounds, which were exclusively detected in the BMB strain. Many of the VOCs detected in the CCAP and, in particular, in the BMB strain have been reported as antimicrobial agents. We suggest that the array of pheromones and antimicrobial substances could be part of an allelopathic strategy of the BMB strain, dominated by oval cells, thus reflecting the benthic life stage of this morphological form. These findings show the potential for bioactive metabolites in the BMB strain. 相似文献
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耕作方式对紫色水稻土总有机碳及颗粒态有机碳的影响 总被引：2，自引：0，他引：2
为研究耕作方式对西南地区紫色水稻土总有机碳及颗粒态有机碳的影响,以1989年设立的位于西南大学农场的农业部重庆紫色土生态环境重点野外科学观测试验站内的长期免耕试验田为对象,研究在冬水田平作（DP）、水旱轮作（SH）、垄作免耕（LM）、厢作免耕（XM）和垄作翻耕（LF）5种不同耕作方式下,土壤中总有机碳（TOC）含量、颗粒态有机碳（POC）含量、颗粒态土壤质量分数和颗粒态有机碳分配比在土壤中的分布特点。结果表明,不同的耕作方式主要对表层土壤的TOC、POC分布产生显著影响,其中LM对提高积累TOC和POC贡献最大;0-60 cm土层TOC含量变化范围为7.10～34.45 g/kg,颗粒态土壤质量分数所占比例为30.38%～45.65%,POC含量为1.31～19.39 g/kg,各数值基本变化趋势都是随土壤深度的增加而减小。TOC与POC都可作为评价耕作方式影响紫色水稻土土壤质量变化与固碳能力的有效指标,但相同耕作制度下POC变化幅度更大,对其响应也更为敏感。从TOC和POC的关系来看,不同耕作制度下有机碳的增加与土壤物理保护能力的提高有关,免耕方式有利于有机碳以及颗粒态有机碳的保护和稳定。 相似文献