Water repellency increases soil infiltration opportunity time. Also soil hydraulic properties affects by soil water repellency. The main objective of this study was to compare the hydraulic properties of soils under different water repellency levels. Therefore, Three le More
Water repellency increases soil infiltration opportunity time. Also soil hydraulic properties affects by soil water repellency. The main objective of this study was to compare the hydraulic properties of soils under different water repellency levels. Therefore, Three levels of water repellency (zero, weak and strong) were artificially created in a silty clay loam soil by adding urban sewage sludge (S0=0:100; S50=50:50 and S80=80:20 sludge weight: soil ratio). Soil water retention curve and water repellency were determined using sand box and pressure plate apparatus and water drop penetration time (WDPT) method, respectively. Van Genuchtens parameters (n, α, m, θs, θr) were determined using RETC software. The results showed that an addition of urban sewage sludge to soils led to an increased WDPT (61 and 25 times) in the water repellency Soils (S80 and S50) .water content corresponds to matric potentials has changed with increasing soil water repellency, also soil water retention curve has changed to biomodal curve in the repellent soils. It shows that the Van Genuchtens parameters affected by water repellency. Also, adding of urban sewage sludge on the soil hydraulic conductivity was significant (P ≤0.0001) and resulted in a decreased 33.80-46.20% in in soil hydrophobicity.
Manuscript profile
Reducing irrigation losses due to surface evaporation by using water repellent soil surface can help in maintaining water in the current situation that our country is suffering from water deficit. In this research, the effect of creating a water-repellent layer on the s More
Reducing irrigation losses due to surface evaporation by using water repellent soil surface can help in maintaining water in the current situation that our country is suffering from water deficit. In this research, the effect of creating a water-repellent layer on the soil surface in the form of anti-evaporation mulch layer was evaluated on three soil textures (sandy loam, loam and clay loam). For this purpose, soils artificially hydrophobized by Stearic acid at four different concentrations and water drop penetration time method to obtain four different degrees of water repellency. And its effect on the rate of surface evaporation from the small lysimeters (with height and diameter 30 cm) located at the ground was investigated in the form of water-repellent layer with three-centimeter thickness. All experiments were conducted at a field in Marand area (latitude: 38° 25' 16.87'' N and longitude: 45° 47' 30.30'' E) in summer 2016. The experiments were performed in a completely randomized design with five treatments degree of water repellency and three replications. After analysis by SPSS and Duncan test (5% level), the average comparison carried out between evaporation in the different water repellency degrees for three soils. The results showed that the surface the water-repellent layer significantly decreased the amount of evaporation in the mentioned three soils. Also, the surface evaporation reduction rate was increased with increasing the water repellency degree. The maximum reduction of evaporation with increasing in the water repellency degree compared to the control treatment (zero degrees of water repellency) was 78.3 %, 42.2 % and 30.1 % in the sandy loam, loam and clay loam soil, respectively.
Manuscript profile
Crop residue burning has been proved to have negative impacts on regional atmospheric environment, soil organic material, reduce soil fertility for long term and soil and water pollution. Therefore, the aim of this study is to investigate the effect of Burning the wheat More
Crop residue burning has been proved to have negative impacts on regional atmospheric environment, soil organic material, reduce soil fertility for long term and soil and water pollution. Therefore, the aim of this study is to investigate the effect of Burning the wheat residue and sawdust on the water repellency of soil. For this purpose, sampling was done of soil surface (0-15 cm) in the east of Ahvaz city in four treatments: sawdust, burned sawdust, wheat residue and burned wheat residue, with 3 replications in ratio of 5, 10 and 25 presents by weight. for measure soil water repellency, was used water drop penetration time (WDPT) method. Analysis of obtained data and mean comparisons were done with using SPSS software and drawing charts with Excel. The results showed that the average water drop penetration time into the soil was 116.33 seconds, the soil was placed in the strongly water repellent class. With the addition sawdust and wheat residues to the soil, were decreased the amount of water penetration into the soil. So that the (WDPT) time from 116.33 in blank treatment decreased to 62.67 and 47.67 second (respectively) in the 25% treatment. The water repellency class was changed from strongly to slightly water repellent. But burned sawdust and burned wheat residues were increased the amount of water penetration into the soil, so that the (WDPT) from 116.33 in blank treatment increased to 923 and 1008.33 second (respectively) in the 25% treatment.
Manuscript profile
In this study, cerium oxide coatings were fabricated by electrochemical deposition method on copper substrates. The effect of applied current density on morphology, crystallographic structure, surface chemistry, surface roughness & wetting property of coatings was i More
In this study, cerium oxide coatings were fabricated by electrochemical deposition method on copper substrates. The effect of applied current density on morphology, crystallographic structure, surface chemistry, surface roughness & wetting property of coatings was investigated by scanning electron microscopy, X-ray diffractometry, Fourier transform infra-red spectroscopy, atomic force microscopy & static water contact angle measurement methods. The results showed that, by increasing the applied current density, cerium oxide coatings become thicker & rougher including more cracks. Also decreasing of applied current density lead to enhanced growth of (002) crystallographic planes & crystallite size in the microstructure of cerium oxide coatings. More hydrophilic cerium oxide coatings were fabricated at higher applied current densities. Although as-deposited cerium oxide coatings were hydrophilic but their behavior changed to hydrophobic as a result of long exposure to atmosphere & hydrocarbon adsorption. The hydrocarbon adsorption was higher in the case of cerium oxide coatings fabricated at higher applied current densities.
Manuscript profile
