Biochar application reduces protein sorption in soil     

《Organic Geochemistry》2015

The application of biochar (BC) as a soil amendment is of growing interest. BC has recently been shown to decelerate the cycling of soil organic N, and adsorption of proteins to BC surfaces has been put forward as an explanation. However, the effect of BC on the sorption of proteins in soil is largely unknown. The main objective of this study was therefore to test the sorption of a model protein (bovine serum albumin, BSA) on a soil amended with different types of BC. Contrary to our assumption, BC application reduced the sorption of BSA. The BC feedstock type and pyrolysis temperature affected BSA sorption; however, the underlying mechanisms require further investigation. BC-induced liming had no effect on BSA sorption, while BC’s hydrophobicity and surface area seemed to be important factors.  相似文献   

Evaluation of redox versus thermal maturity controls on δ15N in organic rich shales: A case study of the Woodford Shale,Anadarko Basin,Oklahoma, USA     

《Organic Geochemistry》2015

Bulk sedimentary nitrogen isotopes (δ¹⁵N_bulk) have been primarily used to identify bottom water redox states during deposition in sedimentary environments that have not undergone significant diagenetic or catagenetic alteration. Recently, the utility of sedimentary δ¹⁵N_bulk as a paleoredox proxy in hydrocarbon-bearing shale intervals was demonstrated by qualitatively correlating the δ¹⁵N_bulk profiles from shale units to their depositional redox conditions. However, the effect of thermal maturity on the δ¹⁵N_bulk signal remains unknown. We analyzed samples from three cores from the Devonian–Mississippian age Woodford Shale in the Anadarko Basin with vitrinite reflectance values ranging from the oil window to the gas window in order to investigate how depositional redox conditions and thermal maturation affect the bulk sedimentary δ¹⁵N signals. Our results indicate that the δ¹⁵N_bulk values for the Woodford do not correlate with thermal maturity. Instead, the δ¹⁵N_bulk values primarily reflect the depositional redox conditions, which are supported by trace metal concentrations and depositional features such as burrow abundance and lamination. The expected relationship between δ¹⁵N_bulk and paleoredox conditions was observed both within each core and between cores on a basin wide scale, with samples deposited under suboxic bottom water conditions having higher δ¹⁵N_bulk values than those deposited under anoxic bottom water conditions. Our data also indicate that redox bottom water column conditions in the Anadarko Basin varied spatially and temporally during the deposition of the Woodford Shale.  相似文献   

Effects of contour hedgerow intercropping on nutrient losses from the sloping farmland in the Three Gorges Area, China   总被引：3，自引：1，他引：2  

Tao Wang  Bo Zhu  Lizhong Xia 《山地科学学报》2012,9(1):105-114

Eutrophication is recognized as one of the major environmental problems in the Three Gorges Reservoir.Contour hedgerows have been used as a major soil and water conservation measure in this area.Accordingly,a two-year study was conducted to investigate the effects of contour hedgerow intercropping on nutrient loss from sloping farmland in this area.Four treatments were applied:(1) Maize + Soybean,(2) Maize,(3) Maize + Alfalfa,and(4) Maize + Hemerocallis citrina Baroni.Results indicated that nutrient loss in the control treatment(Maize) was serious,especially the average loss flux of total nitrogen(2245.8 mg) and total phosphate(2434.2 mg) in a typical rainfall event.However,the nutrient losses by runoff in the other three treatments with contour hedgerow intercropping showed significant reduction.Compared with the control treatment,the total nitrogen loss in the Alfalfa and Hemerocallis citrina Baroni decreased by 80.9% and 85.0%,respectively,and the total phosphorus loss in the two treatments decreased by 91.2% and 92.5%,respectively.Therefore,it is concluded that nutrient losses could be reduced by using contour hedgerows in the Three Gorges Region.Reducing runoff volume and sediment loss was the main mechanisms of contour hedgerow intercropping to reduce nutrient loss.  相似文献   

福建不同地区人工引种无瓣海桑(Sonneratia apetala)生理生态研究     

李元跃  段博文  陈融斌  潘文  周海超  王雷  陈扬  曾晨  黎中宝 《海洋与湖沼》2012,43(1):73-77

采用乙醇提取法、纳氏比色法、钼锑抗显色法及F-C法分别研究了人工引种于福建省漳浦、集美、泉港、连江无瓣海桑(Sonneratia apetala)成熟叶片的生理指标:叶绿素、氮、磷及总酚含量。结果表明,4个地区叶片叶绿素a含量在(1.44±0.54)—(2.52±0.94)mg/g之间波动,叶绿素b含量范围在(0.54±0.02)—(0.94±0.11)mg/g之间,叶绿素a/b随着纬度的升高有增大趋势,表明随纬度升高无瓣海桑对蓝紫光需求比例增大;各地点无瓣海桑氮、磷含量均无显著差异,且N:P比值均小于14,表明均存在N限制;总酚含量随着纬度的升高而逐步升高,可能与无瓣海桑生长条件随纬度的上升而受到外界环境胁迫增大有关。  相似文献   

Recent environmental changes on Banks Island (N.W.T., Canadian Arctic) quantified using fossil diatom assemblages     

Darlene S. S. Lim  John P. Smol  Marianne S. V. Douglas 《Journal of Paleolimnology》2008,40(1):385-398

Banks Island (N.W.T.) has become a focal point for climate change studies in the Canadian Arctic. However, long-term climatic and environmental data are very sparse from this large island, as they are for the entire southwestern region of the Canadian Arctic Archipelago. In this paleolimnological study, diatom species assemblage shifts documented in cores collected from a pond and a lake on Banks Island were interpreted to represent a response to climate warming commencing in the nineteenth century. We found that, although the timing and overall nature of the species changes in the two cores were consistent, the signal was muted in the deeper site likely as a result of differences in ice cover extent and duration between lakes and ponds. A high-resolution study was also conducted from a second pond, at sub-decadal resolution, that only spanned the last ∼60 years. In the deeper lake site, Fragilaria construens and F. pinnata dominated the assemblages, similar to those noted in other high Arctic regions where lakes are characterized by extended ice cover. In contrast, Denticula kuetzingii dominated the shallower ponds and, in the case of the pond core representing the longer time period, this taxon increased in the post-1850 sediments, likely coincident with climate warming. In all cores, diatom assemblages became more diverse and Achnanthes species (particularly A. minutissima) increased from ∼1850 to the present, similar to changes documented in other Arctic regions. Beta diversity values calculated for the diatom species changes indicated that assemblage shifts in the Banks Island cores were of similar magnitude to those recorded in other Arctic regions with high species turnover, such as Ellesmere Island. A diatom-based Total Nitrogen (TN) transfer function previously developed for Banks Island was applied to the three ²¹⁰Pb dated cores as an exploratory tool for inferring past changes in nitrogen concentrations. In both the lake and pond cores, diatom-inferred TN concentrations tended to increase in the more recent sediments, as may be expected with warming; however these trends were not very distinct.  相似文献   

Relative Abundance of Ammonia Oxidizers,Denitrifiers, and Anammox Bacteria in Sediments of Hyper‐Nutrified Estuarine Tidal Flats and in Relation to Environmental Conditions          下载免费PDF全文

Xiaoli Zhang  Hélène Agogué  Christine Dupuy  Jun Gong 《洁净——土壤、空气、水》2014,42(6):815-823

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Application of Regional Nutrient Management Model in Tunxi Catchment: In Support of the Trans‐boundary Eco‐compensation in Eastern China          下载免费PDF全文

Zeli Li  Maohui Liu  Yue Zhao  Tao Liang  Jian Sha  Yuqiu Wang 《洁净——土壤、空气、水》2014,42(12):1729-1739

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Dependence of eelgrass (Zostera marina) light requirements on sediment organic matter in Massachusetts coastal bays: Implications for remediation and restoration     

W.J. Kenworthy  C.L. Gallegos  Charles Costello  Donald Field  Giuseppe di Carlo 《Marine pollution bulletin》2014

Using a calibrated bio-optical model we determined that the optical water quality conditions in several nitrogen-impaired embayments and in one unimpaired system were within the range of values known to support eelgrass growth. We also used the model to identify a range of light requirements for eelgrass (Zostera marina). Higher eelgrass light requirements, expressed as a percentage of surface-incident irradiance, corresponded with higher sediment organic matter content. These results corroborated findings by previous studies which indicate a generalized relationship: seagrasses growing in turbid conditions with poorer water and sediment quality have higher light requirements than those growing in less degraded conditions. The mechanistic reason for the variation in light requirements is still not completely explained and cannot be attributed to a single independent variable. Varying light requirement have important implications for eelgrass protection and should be considered when setting restoration targets for eelgrass in water quality and nitrogen remediation programs.  相似文献   

Nitrogen and phosphorus losses from agricultural systems in China: A meta-analysis   总被引：2，自引：0，他引：2  

Di Cao  Wenzhi Cao  Jing FangLongyan Cai 《Marine pollution bulletin》2014

Studies worldwide have indicated that agricultural pollution is the main source of nitrogen and phosphorus (N and P) in surface waters. A systematic understanding of N and P sources and sinks in agricultural systems is important for selecting the appropriate remedial strategies to control nutrient losses and water pollution. Based on nationwide data and a long-term monitoring program in Southeast China, the nationwide spatial and temporal patterns of N and P losses and the relationships between such losses and N and P inputs and rainfall were analyzed. The results showed that the annual nutrient losses from agricultural systems in China strongly varied, and the N/P values ranged from 0.01 to 51.0, with a majority at approximately 0–20, and an arithmetic mean of 9.73; these values mostly overlap the suitable range of N/P (6–15) for red bloom algae.  相似文献   

Development of a Practical Tool for the Assessment of Biological Performances in Wastewater Treatment Plants          下载免费PDF全文

Francesca F. Malinverni  Barbara Ruffino 《洁净——土壤、空气、水》2016,44(11):1435-1443

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