نتایج جستجو برای: soil

تعداد نتایج: 180737  

2010
GERGELY TOTH

Executive Summary Soil quality is an account of the soil's ability to provide ecosystem and social services through its capacities to perform its functions under changing conditions (after Tóth et al. 2007.) The concept of soil quality expressed by this definition allows practical applications with regards to targeted social and/or ecosystem services, including agri-environmental services. The ...

2008
N. N. Das B. P. Mohanty M. H. Cosh T. J. Jackson

Soil moisture status in the root zone is an important component of the water cycle at all spatial scales (e.g., point, field, catchment, watershed, and region). In this study, the spatio-temporal evolution of root zone soil moisture of the Walnut Gulch Experimental Watershed (WGEW) in Arizona was investigated during the Soil Moisture Experiment 2004 (SMEX04). Root zone soil moisture was estimat...

2003
Laura E. Scott-Denton Kimberlee L. Sparks Russell K. Monson

We examined soil respiration to determine what measurable environmental variables can be used to predict variation in soil respiration rates, spatially and temporally, at a high-elevation, mixed conifer, subalpine forest site at the Niwot Ridge Ameriflux Site in Colorado. For three summers, soil respiration rates were measured using soil collars and a portable gas-exchange system. Transects of ...

2007
Emily A. Carter W. Michael Aust James A. Burger

Harvest operations conducted under conditions of high soil moisture on a wet pine flat in South Carolina resulted in a high degree of soil surface disturbance. Less soil surface disturbance occurred when soil moisture content was lower. Soil strength varied by soil disturbance class in wet harvested locations and highly disturbed areas were associated with low soil strength and elevated levels ...

2013
Mark S. Johnson Eduardo Guimarães Couto Osvaldo B. Pinto Jr Juliana Milesi Ricardo S. Santos Amorim Indira A. M. Messias Marcelo Sacardi Biudes

The Pantanal is a biodiversity hotspot comprised of a mosaic of landforms that differ in vegetative assemblages and flooding dynamics. Tree islands provide refuge for terrestrial fauna during the flooding period and are particularly important to the regional ecosystem structure. Little soil CO₂ research has been conducted in this region. We evaluated soil CO₂ dynamics in relation to primary con...

2002
A. J. Franzluebbers

Soil quality is a concept based on the premise that management can deteriorate, stabilize, or improve soil ecosystem functions. It is hypothesized that the degree of stratification of soil organic C and N pools with soil depth, expressed as a ratio, could indicate soil quality or soil ecosystem functioning, because surface organic matter is essential to erosion control, water infiltration, and ...

2013
L. Concostrina-Zubiri I. Martínez A. Escudero

Morphological and physiological characteristics of biological soil crusts (BSCs) enhance soil stability and fertility, and influence soil chemistry. However, the effect of BSCs on soil physico-chemical properties may vary depending on taxa (cyanobacteria, lichen, bryophytes) and species, and be susceptible to soil surface disturbance. We examined a wide variety of soil physico-chemical properti...

2006
Autumn S. Wang Rufus L. Chaney Thierry A. Delorme Marla McIntosh

Phytoextraction of soil Cd and Zn may require reduction in soil pH in order to achieve high metal uptake. Reducing the pH of high metal soil, however, could negatively affect soil ecosystem function and health. The objectives of this study were to characterize the quantitative causal relationship between pH and soil biological activities in two Zn and Cd contaminated soils and to investigate th...

2017
Masahiko Katoh Elsya Risky Takeshi Sato

This study conducted plant growth tests using a rhizobox system to quantitatively determine the distance of immobilization lead migrating from contaminated soil into uncontaminated rhizosphere soil, and to assess the lead phases accumulated in rhizosphere soil by sequential extraction. Without the hydroxyapatite, exchangeable lead fractions increased as the rhizosphere soil got closer to the co...

Journal: :Environmental Health Perspectives 1995
E J Stanek E J Calabrese

Soil ingestion estimates play an important role in risk assessment of contaminated sites, and estimates of soil ingestion in children are of special interest. Current estimates of soil ingestion are trace-element specific and vary widely among elements. Although expressed as daily estimates, the actual estimates have been constructed by averaging soil ingestion over a study period of several da...

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