H.r. Rahmani, M. Kalbasi, S. Hajrasuliha,
Volume 4, Issue 4 (1-2001)
Abstract
Soil as the third major component of our environment is exposed to different kinds of pollution. Lead has been recognized as a factor in environmental pollution. Pollution of soil and plants along the highways and roads by Pb from automobile exhaust gases has extensively been reported as the most important pollutant source in the environment. This research was carried out to determine the degree of soil pollution along the following highways: Rasht-Anzaly (Anzaly area), Kelachay-Ramsar (Ramsar area), Tehran-Karaj (Karaj area) and Isfahan-Tehran (Delijan area). In each location a transect of 100 meters long, perpendicular to the highway axis, was selected for sampling. Soil samples at different depths were taken from different distances from the highway and analysed for some physical and chemical characteristics and total Ph content by 5M HNO3 extraction.
Results indicated that the total Pb content of soil decreased exponentially with distance from the roadside. Total Pb content of soil decreased sharply with depth in all highways except in one area indicating that Pb was retained in the surface soil and that its movement down to the deep soil was slow. Total Pb content of soils was highly and directly related to the traffic volume.
H. Bayat, A.a. Mahbobi, M.a. Hajabbasi, M.r. Mosaddeghi,
Volume 11, Issue 42 (1-2008)
Abstract
Tillage is one of the important managing factors that can destroy or improve soil structure. Soil structure is affected by the machines and shape of the wheels. Field experiments were conducted at Hamadan Agricultural Research Station on a coarse loamy mixed mesic Calcixerolic Xerocrepts soil to measure and evaluate the effects of tillage and wheel-induced compaction on selected soil physical properties. Treatments included tillage methods (Moldboard Plow and Chisel Plow, (MP, CP)) performed using three customary tractors in Iran [John Deer (J), Romany (R) and Massey Ferguson ( MF) ]. Traffic zone and non traffic zone were other treatments. A split-plot design with three replications was used in a completely randomized arrangement of treatments. Soil samples were taken at the end of wheat growth season in traffic and non- traffic zone and from four layers and compared for bulk density (BD), cone index (CI), and mean weight diameter (MWD). The influence of both tillage methods on BD in most soil depths was not significant, meanwhile, BD was higher in the deeper layers. Wheel traffic did not affect BD significantly, but its effect decreased by increasing the depth. Commonly, conservation tillage increased structural stability as evaluated by MWD. Cone index illustrated the same trend as for BD, with some variation because of it higher sensitivity, so it was significantly was increased in CP rather than in MP for the traffic zone. Such a difference was not observed in non-traffic zone. The CI was also significantly increased in traffic zone compared with non-traffic zone. J significantly increased CI in two first layer in comparing with MF, but there was not significant difference between J and R. The MWD was increased by chisel plow in non-traffic zone and this increment was significant in fourth soil layer (22.5- 30 cm). Wheel traffic caused the increase of MWD in the second layer and significant difference was not observed in other layers. Overall, R caused less destruction in soil structure and tillage methods changed some of soil physical properties.
Z. Mahmoodi, H. Khademi ,
Volume 18, Issue 67 (6-2014)
Abstract
Atmospheric dust is an important source of heavy metals, particularly in urban environments. Heavy metals can easily attach to dust particles and be distributed in large areas. The objective of this study was to evaluate the status of major heavy metals in the atmospheric dust of Isfahan and adjacent cities. A total of 144 dust samples were taken during a period from August to December 2010 from Isfahan, Khomeynishahr, Falavarjan, Mobarake and Zarinshahr cities. Dust samples were extracted with HNO3 65% and the total concentration of metals including Pb, Zn, Cd, Cu, Ni, Co, Cr and Mn in the samples was measured by an atomic absorption spectrometer. The mean concentration of these metals was 223.5, 470.3, 3.5, 71.0, 82.0, 26.5, 24.4 and 426.3 mg kg-1, respectively. Results indicated that heavy metals concentration in any area was different depending on the source of pollution and it was much higher than the mean concentration of the corresponding heavy metal in soils. Besides, the highest deposition rate of all the heavy metals in this study was found in November-December period. This could be attributed to an increase in the use of heating systems and also to a temperature inversion event prevailed in the area. Atmospheric deposition seems to be an important pathway of heavy metals addition to soils. For example, it is responsible for 35-91% and 12-47% of Pb and Cd entering the soil in the area, respectively.
M. Najafi-Ghiri, H.r. Boostani, A. R. Mahmoodi, F. Dehghanpoor, M. Besh,
Volume 23, Issue 4 (2-2020)
Abstract
Astragalus fasciculifolius is one of the most distributed plant species in the arid and semiarid regions of southern Iran. It may be well grown on roadside. This investigation was carried out to study the effect of road and its traffic intensity on the soil physicochemical properties and plant nutrients availability of roadside and to monitor the concentration of nutrients in the aerial parts of Astragalus fasciculifolius. Thirty soil and plant samples from roadside and 100 m distance from road were randomly collected and some physicochemical soil properties and nutrients availability were determined. Concentrations of the nutrients in the aerial parts of the plants were also determined. The results indicated that roadside soils had more sand and calcium carbonate equivalent than the adjacent lands. Soils of the main roadside had less K and more Fe, Mn, Zn and Cu than the adjacent lands; this difference in local road was observed only for Fe and Cu. Nutrients concentration in the aerial parts of the plants was affected by road, and P, K, Mn and Zn showed significant increases in the roadside plants. Concentrations of P, Fe, Zn and Cu in plants grown in main roadside and concentrations of Fe and Zn in plants grown in the local roadside were correlated with their contents in the soils. The effect of roads on soil properties change and nutrients availability may be related to the addition of road bed and emission of vehicles. Generally, it could be concluded that roadside soils had more suitable water and nutrition conditions for the growth of Astragalus fasciculifolius, as compared to the soils of the adjacent lands.
