Laboratory studies were conducted to evaluate effect of microwave irradiation of sandy loam soil on thermal energy absorption and control of plant-parasitic nematodes when air dry soil layers were placed on top of less moist, moist, and wet soil layers. The soil was packed in 12 cm high and 10 cm dia columns to a bulk density of 1.4 g/cm3. Moisture contents of air dry, less moist, moist, and we...

The potential for non-point-source pollution of surface waters from agricultural lands continues to be a concern. Our objective was to determine the effect of surface residue management and fertilizer application timing in regards to soil moisture conditions on nutrient losses in runoff. Studies were conducted using a rainfall simulator that applied 125 mm h-1 for 3 h to an Austin (Udorthentic ...

Limited information is available on how soil and leaf populations of the sudden oak death pathogen, Phytophthora ramorum, may differ in their response to changing weather conditions, and their corresponding role in initiating the next disease cycle after unfavorable weather conditions. We sampled and cultured from 425 trees in six sites, three times at the end of a 3-year-long drought and twice...

A dielectric mixing model has been developed to calculate the complex permittivity of wet soils at 5.65 GHz (C-band) and 9.5 GHz (X-band) microwave frequencies. The model considers the complex permittivity of dry soil as initial parameter. The complex permittivity of wet soil has been estimated in terms of the complex permittivity of dry soil, the complex permittivity of water at a given microw...

Global climatic change may cause changes in regional precipitation that have important implications for forest growth in the southern United States. In 1993, a stand-level experiment was initiated on Walker Branch Watershed, Tennessee, to study the sensitivity of forest saplings and large trees to changes in soil water content. Soil water content was manipulated by gravity-driven transfer of pr...

With the improvement of the urbanization level, the mixed city water has surged and the traditional denitrogenating cost in the course of wastewater reuse has been unbearable. This experiment used the technology of the constructed rapid infiltration (CRI) and applied the soil column simulation method in the laboratory. The results show that nitrogen removal rates of two soil columns are 73.73% ...

in order to study the effect of flaming on seed viability of sinapis arvensis l., changes in microorganisms population and physicochemical characteristics of soil after canola (brassica napus l.) harvesting, an experiment was carried out based on randomized complete block design with four replications and eight treatments at karaj research center, iran, during 2005- 2006. after harvesting canol...

This research investigates the interannual variability of soil moisture as related to large-scale climate variability and also evaluates the spatial and temporal variability of modeled deep layer (40–140 cm) soil moisture in the Upper Colorado River Basin (UCRB). A three layers hydrological model VIC-3L (Variable Infiltration Capacity Model – 3 layers) was used to generate soil moisture in the ...

Understanding the factors shaping species distribution patterns along tropical rainfall gradients is necessary to predict the consequences of climate change for tropical tree communities. Direct effects of water availability exclude wet forest species from dry forests, but the exclusion of dry forest species from wet forests remains unexplained. We tested the hypothesis that high light and nutr...

To better understand carbon (C) cycling in arctic tundra we measured dissolved C production and export rates in mesocosms of three tundra vegetation types: tussock, inter-tussock and wet sedge. Three flushing frequencies were used to simulate storm events and determine potential mass export of dissolved C under increased soil water flow scenarios. Dissolved C production and export rates differe...