Effects of poultry manure amendment on phosphorus uptake by ryegrass,soil phosphorus fractions and phosphatase activity     

Heidi M. Waldrip  Zhongqi He  M. Susan Erich 《Biology and Fertility of Soils》2011,47(4):407-418

Poultry manure (PM) contains a large proportion of phosphorus (P) in mineral-associated forms that may not be readily available for plant uptake. In addition, PM application influences both chemical and biotic processes, and can affect the lability of native soil P. To investigate the effects of PM on soil P availability, we grew ryegrass (Lolium perenne) in greenhouse pots amended with poultry manure. Biomass was harvested at 4, 8, and 16 weeks following PM application, with soil separated into rhizosphere and bulk fractions. Soil was sequentially extracted by H₂O, 0.5 M NaHCO₃, 0.1 M NaOH, and 1 M HCl, and inorganic P (P_i) and enzymatically hydrolyzable organic P (P_oe) were quantitated. Root P concentrations were 37% higher and total P uptake 59% higher with PM application than Control. At week 16, there was 30% more labile-P_i (H₂O- plus NaHCO₃-P_i) in the rhizosphere with PM than in Control. Phosphodiesterase activity increased with PM application. Furthermore, acid phosphomonoesterase, alkaline phosphomonoesterase, and phosphodiesterase activities were all higher in the rhizosphere than in bulk soil at week 16 with PM, indicating that increased labile-P_i was due primarily to stimulation of soil phosphatases to mineralize NaOH-P_oe. Soil pH increased with PM application and plant growth, and may have promoted P availability by decreasing sorption of Al- and Fe-associated inorganic and organic phosphates. These results demonstrate that whereas PM application may initially increase NaOH and HCl-P_i, these fractions can be readily changed into labile-P and do not necessarily accumulate as stable or recalcitrant P in soil.  相似文献   

Einige Untersuchungen zur Differenzierung von Rhizobienstämmen und zur Saatgutimpfung der Leguminosen     

Erich Schmidt 《Archives of Agronomy and Soil Science》2013,59(11):1043-1054

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余英时:《朱熹的历史世界》     

田浩 《湖南农业大学学报(自然科学版)》2004,(5)

余英时的《朱熹的历史世界》提供了更详细更具史实的研究,说明了政治斗争在朱熹的思想和道学的发展中的关键作用,通过考察朱熹的历史世界,余先生提供了一种替代流行的哲学史研究的新路径,将道学与政治文化联系在一起,对道学家来说,政治文化是比哲学更基础的东西,理解政治文化与党争对于理解朱熹等道学士大夫的思想具有一定的重要意义。  相似文献   

Cortisol release and heart rate variability in sport horses participating in equestrian competitions     

Mareike Becker-Birck  Alice Schmidt  Juliane Lasarzik  Jörg Aurich  Erich Möstl  Christine Aurich 《Journal of Veterinary Behavior: Clinical Applications and Research》2013,8(2):87-94

Equestrian competitions require both physical activity and mental adaptation in horses. Cortisol, heart rate, and heart rate variability (HRV) are accepted stress parameters and, in this study, have been determined in horses (n = 13) participating in equestrian competitions for up to 3 consecutive days. Participation in competitions caused an increase in salivary cortisol concentrations (e.g., on day 1 from 1.0 ± 0.2 before to 2.2 ± 0.4 ng/mL after the competition, days 1 and 2: P < 0.001, day 3: P < 0.05) and an increase in heart rate (days 1 and 2: P < 0.001, day 3: P = 0.01). A consistent decrease in HRV occurred only in response to the final competition on day 3 (P < 0.01). When horses competing in dressage and show jumping were compared, cortisol release and HRV did not differ between groups, but after the competition, heart rate was lower in dressage than in show jumping horses (P < 0.05). Heart rate increased not only during the actual competition but already when horses were prepared in their stables (e.g., day 1: ?60 minutes, 38.6 ± 2; ?5 minutes, 77 ± 7; competition, 81 ± 10 beats per minute; P < 0.01). In conclusion, participation in equestrian competitions caused an increase in cortisol release and heart rate and a decrease in HRV variables. However, competitions were not a major stressor compared with other anthropogenic challenges such as transport, to which horses are exposed regularly.  相似文献   

The native South American crayfishes (Crustacea,Parastacidae): state of knowledge and conservation status          下载免费PDF全文

Mauricio Pereira Almerão  Erich Rudolph  Catherine Souty‐Grosset  Keith Crandall  Ludwig Buckup  Julien Amouret  Ana Verdi  Sandro Santos  Paula Beatriz De Araujo 《水产资源保护:海洋与淡水生态系统》2015,25(2):288-301

User-Based Photometer Analysis of Effluent from Advanced Nitrogen-Removal Onsite Wastewater Treatment Systems     

Bianca N. Ross  George W. Loomis  Kevin P. Hoyt  Jose A. Amador 《Water, air, and soil pollution》2018,229(12):389

Advanced nitrogen-removal onsite wastewater treatment systems (OWTS) are used to reduce total nitrogen (N) levels in domestic wastewater. Maintaining system performance requires regular monitoring and in situ rapid tests can provide an inexpensive option for assessing treatment performance. We used a portable photometer to measure ammonium and nitrate concentrations in final effluent from 46 advanced N-removal OWTS, sampling each site at least three times in 2017. To assess photometer accuracy, we compared measurements made using the photometer with those determined by standard laboratory methods using linear regression analysis and a two-tailed t test to compare regression parameters to those for a perfect linear relationship (slope?=?1, intercept?=?0). Our results show that photometer-based analysis reliably estimates inorganic N (ammonium and nitrate) concentration in field and laboratory settings. Photometer-based analysis of the sum of inorganic N species also consistently approximated the total N concentration in the final effluent from the systems. A cost-benefit analysis indicated that the photometer is a more cost-effective option than having samples analyzed by commercial environmental testing laboratories after analysis of 8 to 33 samples. A portable photometer can be used to provide reliable, cost-effective measurements of ammonium and nitrate concentrations, and estimates of total N levels in advanced N-removal OWTS effluent. This method can be a viable tool for triaging system performance in the field, helping to identify systems that are not functioning properly and may need to be adjusted or repaired by an operation and maintenance service provider in order to meet treatment standards.  相似文献   

Gattungsgrenzen bei höheren Discomyceten     

Erich Heinz Benedix 《Genetic Resources and Crop Evolution》1962,10(1):359-371

Zusammenfassung An Hand besonderer Discomyceten-Funde aus dem Jahre 1961 werden einige Nachbargattungen miteinander verglichen und ihre gegenseitigen Grenzen kritisch erörtert. Danach erweist sich die Sonderstellung vonPtychoverpa Boud. nur mikroskopisch als ausreichend begründet.Helvella Quéletii Bres. kann vonAcetabula sulcata (Pers. ex Fr.) Fuck. nicht gattungsmäßig getrennt werden, sondern ist alsAcetabula Quéletii (Bres.) Bx. nov. comb. zu bezeichnen, wenn beide Gattungen nebeneinander bestehen bleiben.Paramitra ochreoides Bx. nov. gen. et nov. spec. wird erstmalig beschrieben und stellt vermutlich einen Übergang von derOtidea-Gruppe (Wynnella Boud.) zu den Aleurieen dar.

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Summary Starting from rare findings ofDiscomycetes in 1961 some closely related genera are compared and their limits discussed critically. The special position ofPtychoverpa Boud. is sufficiently proved only by microscopic characters. To discernHelvella Quéletii Bres. fromAcetabula sulcata (Pers. ex Fr.) Fuck. generically is not possible, it must be designated asAcetabula Quéletii (Bres.) Bx. nov. comb. if both genera shall be maintained. The new describedParamitra ochreoides Bx. nov. gen. et nov. spec. presumably is a transitional fungus between theOtidea-group (Wynnella Boud.) and theAleurieae.

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, 1961 . . Ptychoverpa Boud. .Helvella Quéletii Bres. Acetabula sulcata (Pers. ex Fr.) Fuck. Acetabula Quéletii (Bres.) Bx. nov. comb., .Paramitra ochreoides Bx. nov. gen. et nov. spec. ; Otidea (Wynnella Boud.) Aleurieae.

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Grundsätzliches zur Taumessungsfrage     

Erich von Leick 《Genetic Resources and Crop Evolution》1953,1(1):53-78

Ohne Zusammenfassung  相似文献   

Indirekte Komplementbindung mit Mäuseseren nach Schutzimpfung mit monovalenter Maul- und Klauenseuche-Vaccine     

Erich Traub  G. Bechmann 《Zoonoses and public health》1969,16(3):240-252

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Rapid, multiwell colorimetric assay for measuring neutrophil chemoattractant activity in bronchoalveolar lavage fluid of horses with recurrent airway obstruction.     

Jean A Hall  Dana Hoyt  Clarissa Zuver  Monica M Skinner  John W Schlipf 《Journal of veterinary diagnostic investigation》2006,18(3):257-263

The criteria used to diagnose recurrent airway obstruction (RAO) in affected horses include demonstration of reversible lower airway obstruction and greater than 25% neutrophils in bronchoalveolar lavage fluid (BALF). Additional objective laboratory tests are needed to improve diagnostic accuracy and to monitor response to treatment. The goal of this study was to determine if neutrophil chemoattractant activity of BALF could be measured by using a previously described, rapid, multiwell colorimetric assay for chemotaxis. In this assay, neutrophils that have migrated through a membrane filter are collected into the bottom well of a disposable chemotaxis-cell migration chamber. The number of viable cells collected in the bottom well is quantified by measurement of the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenol tetrazolium bromide (MTT), which is reduced by dehydrogenase in mitochondria of live cells. The number of migrating cells corresponds to the amount of MTT reduced, which is measured with an enzyme-linked immunosorbent assay plate reader. Fourteen adult horses were enrolled in this study, 7 of which had owner histories consistent with RAO. Each horse was sedated, a bronchoalveolar lavage tube was passed, and saline was infused and immediately aspirated. An aliquot of BALF was used for differential cell count, and BALF supernatant was harvested to assess neutrophil chemoattractant activity. Normal control horses and RAO-affected horses were distinguished according to clinical signs and percent neutrophils in BALF. Neutrophil chemoattractant activity of BALF was significantly greater in RAO-affected horses (P = 0.001) compared with control horses. This assay may be useful in future studies for monitoring response to therapy in RAOaffected horses.  相似文献