ABSTRACT- To study the effect of tree roots on increasing water infiltration in soil and also to determine and assess the coefficients of different infiltration models, some infiltration tests were performed in three tree plantation areas in Badjgah, Fars province with different soil textures (clay loam for pear plantation, sandy loam for grape plantation, loamy sand for pine trees). In each pl...

the majority of iran’s area is covered by arid and semiarid climates. in these areas, wind causes more erosion compared to water. therefore, determination of wind characteristics especially its velocity is very important. one of the simplest methods that can supply researchers with the origin of wind erosion in the shortest time is synthesizing sand rose model and interpretation of aerial photo...

The objective of this research was to evaluate the effect of low concentrations of a rhamnolipid biosurfactant on the in situ biodegradation of hydrocarbon entrapped in a porous matrix. Experiments were performed with sand-packed columns under saturated flow conditions with hexadecane as a model hydrocarbon. Application of biosurfactant concentrations greater than the CMC (the concentration at ...

Oil leakage causes soil contamination and induces changes in the physical and mechanical properties of soils. In areas contaminated with oil products such as gasoline, the implementation of civilian operations requires determination and prediction of soil behavior in the existing conditions. In this research work, the effect of oil contamination by gasoline obtained from the National Oil Compan...

Engineers often want to estimate profiles of soil permeability (hydraulic conductivity) as part of the site characterization process. Several methods have been proposed to estimate the coefficient of permeability (k) using CPT results. These methods are generally based on two approaches: (1) estimated soil type and (2) rate of dissipation during a CPTu dissipation test. This paper presents upda...

Colonization of the spermosphere and rhizosphere by plant-beneficial bacteria is limited by competition with indigenous soil microbes for resources such as reduced carbon compounds. A study of the soil microbial community around germinating seeds was undertaken as a necessary first step in understanding the competition between the introduced plant-beneficial bacteria and the indigenous microbia...

Improving water use efficiency and soil properties are two major factors for sustainable development in desert areas. Therefore, this research aims to study the effectiveness of a biological hydrogel, plant vegetation layer, sand and barley straw with rain harvesting techniques through micro-catchment operation on some soil properties including pH, Nitrogen, Electrical conductivity, Sodium Abso...

Bacterial diversity in soil is high relative to more homogeneous environments (e.g., freshwater or marine habitats). Isolation imparted by fragmented aquatic microhabitats in unsaturated soil likely plays a large role in creating this diversity. We evaluate the role of soil texture, which determines the extent and connectivity of microhabitats, in constraining bacterial diversity. Soil samples ...

Bacteria transport in soils primarily occurs through soil mesopores and macropores (e.g., biopores and cracks). Field research has demonstrated that biopores and subsurface drains can be hydraulically connected. This research was conducted to investigate the importance of surface connected and disconnected (buried) biopores on Escherichia coli (E. coli) transport when biopores are located near ...

The identification of breeding sites of sand flies is of great epidemiological interest. A soil emergence trap for investigating potential sand fly breeding sites is described. The trap was tested in two rural areas in the Mogi Guaçu River Valley where the American cutaneous leishmaniasis is an endemic disease. Seventy-three sand fly individuals of three species, Lutzomyia intermedia s. l., L. ...