The effect of Tylenchorhynchus nudus on growth of Kentucky bluegrass was investigated under controlled environmental conditions in both a phytotron and a greenhouse. The nematode significantly reduced weights of clippings, crowns and roots. Pathogenicity was greater in sandy loam soil than in loam and was enhanced by submitting plants to nutrient and/or moisture stresses; soil nutrient level wa...

The kinetics of several steps in the microbial denitrification process in Brookston clay and Fox sandy loam, two soils common to Southwestern Ontario, were studied in the temperature range of 5 to 25 degrees C. The extent of chemical denitrification was also determined in otherwise identical but sterilized soils at temperatures up to 80 degrees C. A gas flow system was used in which soil gases ...

the majority of hydraulic processes under a natural condition in a field are carried out under unsaturated flow conditions. the soil moisture retention curve (smrc) is the most important hydraulic characteristic of an unsaturated soil whose knowledge is of prime importance in soil-water studies such as soil conservation, soil erosion, land evaluation, soil reclamation, and water resources manag...

Using two-dimensional foraging arenas, laboratory tests were conducted to investigate the effect of soil type, soil moisture level and ambient temperature on the exploratory tunneling by Coptotermes formosanus Shiraki. In choice arenas consisting of two substrate types having two moisture levels each, and conducted at a constant temperature of 22 °C, a significantly greater proportion of termit...

Soils sequester and release substantial atmospheric carbon, but the contribution of fungal communities to soil carbon balance under rising CO2 is not well understood. Soil properties likely mediate these fungal responses but are rarely explored in CO2 experiments. We studied soil fungal communities in a grassland ecosystem exposed to a preindustrial-to-future CO2 gradient (250 to 500 ppm) in a ...

in this study, a simulation of tire–soil interaction model was considered with special view to two-dimensional (2-d) fem model of carcass. coefficients of mechanical behavior of silty-loam soil were accurately measured to obtain an effective simulation. the results of simulation which was implemented in matlab7, showed that the radial-ply tire had greater tractive efficiency than bias tire at t...

Concerns for the mounting supply of municipal solid waste being generated combined with decreasing landfill space have compelled military installations to evaluate alternative methods for disposal. One approach to reduce landfilling is the use of a new garbage-processing technology that sterilizes and separates the waste into inorganic and organic components. Thus, a study was initiated to eval...

verticillium wilt verticillium dahliae is now a days commonplace in olive orchards in north of iran. root-knot nematode, meloidogyne javanica, as well is one of the most widely disseminated plant parasitic nematodes in olive orchards of iran. this study was arranged to find the effects of two sets of pot beds on these pathogens' interaction. microsclerotia of verticillium dahliae and j2s o...

Nitrogen (N) export from soils to streams and groundwater under the intensifying cropping schemes of the Pampas is modest compared to intensively cultivated basins of Europe and North America; however, a slow N enrichment of water resources has been suggested. We (1) analyzed the fate of fertilizer N and (2) evaluated the contribution of fertilizer and soil organic matter (SOM) to N leaching un...

American chestnut trees once dominated vast areas of deciduous forest in eastern North America, but the exotic chestnut blight almost eliminated the species from the region. Introduction of blight-resistant American chestnut hybrids will probably start in the next decade after many years of tree breeding. What were the historic effects of chestnut on forest soils, and what changes may follow re...