Playa wetlands are important areas of soil organic carbon and nutrient storage in drylands. We conducted this study to assess how catchment biophysical variables control soil organic carbon and nitrogen in playas and how playas function differently than upland ecosystems. We found that playa organic carbon and nitrogen corresponded primarily with catchment vegetation cover and secondarily with ...

Permafrost is tightly coupled to the organic soil layer, an interaction that mediates permafrost degradation in response to regional warming. We analyzed changes in permafrost occurrence and organic layer thickness (OLT) using more than 3000 soil pedons across a mean annual temperature (MAT) gradient. Cause and effect relationships between permafrost probability (PF), OLT, and other topographic...

The effects of soil continuous cultivation and texture on some its properties, electrical conductivity, total porosity, calcium carbonate content penetration resistance. Six samples material for a layer 0-30 cm were collected from three different sites are Clay, Loam Loamy Sand in Basra Governorate Abi al-Khasib, Karma Zubair. Three these represented the treatment cultivation, planted with alfa...

Soil moisture exhibits spatial and temporal variability. Spatial variability is mostly associated to climatology patterns, topography, soil texture, and vegetation index; where as, temporal variability is primarily associated to rainfall and air temperature events. The spatial variability is modeled by a long-term memory model whereas the temporal variability by a short-term memory model. The l...

These effects on tree growth, which may persist for several decades (Hatchell et al. 1970, Butt 1987, Miller et al. 1996), may lead to shortand long-term reductions in tree growth and forest productivity. The level of soil disturbance will vary with soil texture, forest floor thickness, and soil water content at time of harvest (Miller and Sirois 1986, Corns 1988). In addition, machine type, si...

The entomogenous nematode species Heterorhabditis heliothidis (Kahn, Brooks, and Hirschmann), H. bacteriophora Poinar, Neoaplectana carpocapsae Weiser, and N. glaseri Steiner are promising biological control agents for a broad range of soil-inhabiting insect species (6). Many factors in soil affect nematode survival, movement, and infectivity: Moisture is probably the most important physical fa...