نتایج جستجو برای: soil profile
تعداد نتایج: 398248 فیلتر نتایج به سال:
We used the natural abundance of stable isotopic ratios of hydrogen and oxygen in soil (0.05-3 m depth), plant xylem and precipitation to determine the seasonal changes in sources of soil water uptake by two native encroaching woody species (Pinus ponderosa P. & C. Lawson, Juniperus virginiana L.), and two C(4) grasses (Schizachyrium scoparium (Michx.) Nash, Panicum virgatum L.), in the semiari...
Original scientific paper In this paper a numerical model was used to evaluate water flow in free drainage lysimeters with respect to soil anisotropy (hydraulic conductivity). Lysimeters were installed in undisturbed soil profile on two soil types with different anisotropy (low and high). The soil types were classified as Luvic Stagnic Phaeozem Siltic and Haplic Gleysol Calcaric Eutric Siltic. ...
Seasonal changes over 2 years (2004–2006) in soil moisture content ( v) of frozen alpine frost meadow soils of the QinghaiTibet plateau permafrost region under three different levels of vegetation cover were investigated. Vegetation cover and air temperature changes had significant effects (synergistic effect) on v and its distribution in the soil profile. During periods of soil freezing or tha...
abstract soil salinity within plant root zone is one of the most important problems that cause reduction in yield in agricultural lands. in this research, salinity in soil profile was simulated in tabriz irrigation and drainage network using saltmod and artificial neural networks (anns) models. based on initial spatial distribution of salinity in soil profile, studying area was divided to 4 dif...
it is common in the literature to confront the measured 137cs depth profile with the analytical solution of 1d advection-dispersion equation (ade) calibrated for the time of sampling which is a pure transport model useful for undisturbed soils. the degree of accuracy is strongly associated to the soil texture. it has been proven that soil with high clay content can retain radiocesium better. mo...
Dynamic changes in water and salinity in saline-alkali soils after simulated irrigation and leaching
Soil salinization is a global problem that limits agricultural development and impacts human life. This study aimed to understand the dynamic changes in water and salinity in saline-alkali soil based on an indoor soil column simulation. We studied the changes in the water and salt contents of soils with different degrees of salinization under various irrigation conditions. The results showed th...
This study aims to understand the spatial distribution of organic carbon and its sequestration potential in Tunisian soils. Soil organic carbon (SOC) stock was estimated in the 0-30 cm and to 0-100 cm soil depth for Tunisia using maps of soils and of the departments, combined with results from a soil database. The original soil classification was simplified to nine soils. Tunisia contains 24 go...
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