نتایج جستجو برای: soil recovery
تعداد نتایج: 378324 فیلتر نتایج به سال:
Effects of anthropogenic nitrogen (N) deposition and the ability of terrestrial ecosystems to store carbon (C) depend in part on the amount of N retained in the system and its partitioning among plant and soil pools. We conducted a meta-analysis of studies at 48 sites across four continents that used enriched N isotope tracers in order to synthesize information about total ecosystem N retention...
Remediation of hydrocarbon contaminated soils can be performed both in situ and ex situ using chemical oxidants such as sodium persulfate. Standard methods for quantifying persulfate require either centrifugation or prolonged settling times. An optimized soil extraction procedure was developed for persulfate involving simple water extraction using a modified disposable syringe. This allows cons...
An international interlaboratory study was conducted to determine the performance of a group of laboratories from developing and developed countries. The study used a commercial microwell ELISA on unknown samples spiked with different levels of DDT. The study design was based on Youden pairs and balanced replicates. Two soils, differing in particle size distributions, organic matter content, an...
Two plots in a red pine stand at the Harvard Forest, Massachusetts, have been fertilized for 7 yr with 5 g·m22·yr21 or 15 g·m22·yr21 of N and compared to an unfertilized control to study the effects of chronic N additions on nutrient cycling, plants, and soil. Movement of added N into soils and plant biomass was tracked using additions of an 15N label to the 5 g·m22·yr21 and control plots for t...
Quantitative recoveries of bacteria added to a number of soils were obtained using fluorescein isothiocyanate (FITC) as a stain. Enzyme fluorescence, using fluorescein diacetate or dibutyrate, could not be adapted for the routine counting of metabolizing organisms in soil. Staining with rose bengal gave recoveries of 60-80%. Soil-extract dilution plates revealed 4 X 107 bacteria/g in the 0-10 c...
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An earlier onset of photosynthesis in spring for boreal forest trees is predicted as the climate warms, yet the importance of soil vs air temperatures for spring recovery remains to be determined. Effects of various soil- and air-temperature conditions on spring recovery of photosynthesis in Scots pine (Pinus sylvestris) seedlings were assessed under controlled environmental conditions. Using w...
A simple and reliable method using on-line purge and trap gas chromatography mass spectrometry has been developed for the determination of the fumigant 1,3-dichloropropene (1,3-DCP) in agricultural water and soil samples. The proposed analytical methodology was validated in the target environmental matrices by the analysis of spiked blank matrix samples. Limit of detection values of 0.05 microg...
Rotavirus is a leading cause of gastrointestinal illness worldwide. Rotavirus transmission occurs fecal-orally, and becomes a critical water quality issue when soil and water resources are contaminated with feces. Transport of pathogens to surface water sources depends on their survival in the soil, especially considering the fact that large amounts of fecal material are often applied to agricu...
The productivity of a pasture soil (caatinga) located in the region of São João do Cariri, PB, Brazil was evaluated based an the following microbiological parameters: biomass (measured by fumigation-incubation method), activity (estimated from basal respiration and cellulose decomposition rate), qCO2, and Cmic : Corg ratio. This analysis demonstrated that livestock management in the 'caatinga' ...
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