نتایج جستجو برای: soil profile

تعداد نتایج: 398248  

2013
Stephen L. Young Guy B. Kyser Jacob N. Barney Victor P. Claassen Joseph M. DiTomaso

In a 2-year field study, we quantified lateral root growth patterns and soil water depletion dynamics in the invasive annual Centaurea solstitialis and two native perennials, Elymus glaucus and Grindelia camporum. Centaurea solstitialis produced lateral roots most actively from early April to mid-June, during the late rosette to spiny seedhead stage while both root growth and water depletion we...

2000
Jeffrey P. Walker

Remote sensing provides a capability to make frequent and spatially distributed measurements of surface soil moisture, whilst recent advances in affordable Time Domain Reflectometry probes allow continuous monitoring of profile soil moisture at specific points. We believe that reliable estimation of the spatial and temporal variation of profile soil moisture on a routine basis will require a co...

1999
J. Li S. Islam

Recent studies have shown that a variety of remote sensing techniques may be used for the estimation of soil moisture over large areas. The shallow moisture sensing depth of passive microwave measurements, however, limits the use of remotely sensed soil moisture for many land–atmosphere interaction studies. In this study, a method is proposed for soil moisture profile estimation by sequential a...

2015
Guoqing Hu Xiao Liu Hongbo He Wei Zhang Hongtu Xie Yeye Wu Jiehua Cui Ci Sun Xudong Zhang Xiujun Wang

In conservation tillage systems, at least 30% of the soil surface was covered by crop residues which generally contain significant amounts of nitrogen (N). However, little is known about the multi-seasonal recoveries of the N derived from these crop residues in soil-crop systems, notably in northeastern China. In a temperate agro-ecosystem, 15N-labeled maize residue was applied to field surface...

A.M.  Kabdyrakova, A.R.  Ivanova, A.V.  Panitskiy, A.Ye. Kunduzbayeva, N.V.  Larionova, А.O.  Aidarkhanov,

ABSTRACT Background: This work investigated radioactive contamination in soils of the pine forest in the territory adjacent to Semipalatinsk test site. Materials and Methods: Thirty samples from the soil were collected from six different a soil profile was laid out (research areas). Activity concentrations of 137Cs and 241Am were determined using a Canberra GX-2020 solid-state gamma-spectromet...

2001
Charles McClaugherty

Soil properties change with depth. Layers of soil that are nearly parallel with the soil surface and that are distinguishable from adjacent layers are called soil horizons. Horizons are visible on the vertical wall of a pit dug into the soil; the entire series of horizons visible on this wall is known as a soil profile. An idealized soil profile is illustrated in Figure 1. Soil classification r...

2017
Ren Bai Jun-Tao Wang Ye Deng Ji-Zheng He Kai Feng Li-Mei Zhang

Paddy rice fields occupy broad agricultural area in China and cover diverse soil types. Microbial community in paddy soils is of great interest since many microorganisms are involved in soil functional processes. In the present study, Illumina Mi-Seq sequencing and functional gene array (GeoChip 4.2) techniques were combined to investigate soil microbial communities and functional gene patterns...

Journal: :Journal of environmental quality 2012
Jennifer D Knoepp James M Vose Jerry L Michael Barbara C Reynolds

Imidacloprid is a systemic insecticide effective in controlling the exotic pest (hemlock woolly adelgid) in eastern hemlock () trees. Concerns over imidacloprid impacts on nontarget species have limited its application in southern Appalachian ecosystems. We quantified the movement and adsorption of imidacloprid in forest soils after soil injection in two sites at Coweeta Hydrologic Laboratory ...

2009
Katarina Björklöf Sanja Karlsson Åsa Frostegård Kirsten S Jørgensen

Relatively little is known about the microbial communities adapted to soil environments contaminated with aged complex hydrocarbon mixtures, especially in the subsurface soil layers. In this work we studied the microbial communities in two different soil profiles down to the depth of 7 m which originated from a 30-year-old site contaminated with petroleum hydrocarbons (PHCs) and from a clean si...

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...

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