Tayebeh Sohrabi; GHolamreza Zehtabian
Volume 19, Issue 1 , June 2012, , Pages 17-31
Abstract
Iran with its special geographical position mainly has an arid and semi-arid climate. The average annual rainfall in Iran is about 240 mm equivalent to one-fourth of the world average rainfall. In addition, irregular spatial and temporal distribution of rainfall has caused problems in natural resources ...
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Iran with its special geographical position mainly has an arid and semi-arid climate. The average annual rainfall in Iran is about 240 mm equivalent to one-fourth of the world average rainfall. In addition, irregular spatial and temporal distribution of rainfall has caused problems in natural resources and agriculture and annually huge amount of our water and soil resources are degraded. Since the advent of the farming activities until the present, human needs have been based upon farming activities. Considering the growing population and the social and economic developments, most of rangelands have been subject to rainfed cultivation. Therefore, to prevent further degradation of soil in these regions research should be conducted on agricultural lands and the exploitation methods. For this reason, Taleghan was selected as the study area. Map of the area, including soil maps, land types and the current land use were produced by GIS. After determining the main treatments, soil samples were taken in every part of the area and in agricultural area and soil factors were measured within two groups of soil improvement factors including nitrogen, phosphorus, potassium, humus and lime and soil degradation factors including acidity, sodium adsorption ratio (SAR) and salinity in two depths of 0-10 and >10 cm. These factors were studied in a split-plot design. The results showed significant differences among treatments. According to the results of soil improvement and degradation factors, orchards and rangelands are in an ideal condition and monoculture treatment decreases the performance of the products.
Gholam reza Zehtabian; Marzeyeh Tayeb; Mahshid Souri
Volume 13, Issue 4 , February 2007, , Pages 368-384
Abstract
Salinity is one of the factores affecting the reduction of soil biological potential and vegetation and finally desertification. Water is the most limiting factor for cultivation in arid and semi arid regions. Due to shortage of surface water resources, the pressure is exerted on under ground water ...
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Salinity is one of the factores affecting the reduction of soil biological potential and vegetation and finally desertification. Water is the most limiting factor for cultivation in arid and semi arid regions. Due to shortage of surface water resources, the pressure is exerted on under ground water resources. Meanwhile, over –exploitation of underground water resources and neglecting technical points in exploitation have caused the level of underground water to be dropped. This water level drop in addition to other factors causes the quality of water resources to be changed leading to increasing of salinity. This research has been carried out in kabootarkhan plain, kerman province. In order to study factors salinizing underground water resources in this basin, some baseline data were gathered. Then, sampling of profiles of soil profiles were done in the four soil units (arable lands, ferdowsi, agriculture station and kabootakhan) in the basin in three replications. The laboratory results and existing data were analyzed using SPSS software according to the randomized split-pot design. The results show that in appendage plain of the basin, irrigation with saline water resources in addition to soil texture have caused salinity to be occurred and in clay flat, irrigation has caused salinity to be declined due to the good soil texture and existence of natural drainage.