نتایج جستجو برای: texture of soil

تعداد نتایج: 21188303  

Known of ecosystem of range details and relation bet ween this details including soil and vegetation, is Necessary for optimum management of ranges. To determine the effect of some soil properties on species distribution of Dorema ammoniacum and Rheum ribes in ranges of Baghedar region, Information of vegetation were harvested with systematic-random method in the form of 40 plots and during 4 t...

2012
G. Kweon E. Lund

The goal of accurately mapping soil variability preceded GPS-aided agriculture, and has been a challenging aspect of precision agriculture since its inception. Many studies have found the range of spatial dependence is shorter than the distances used in most grid sampling. Other studies have examined variability within government soil surveys and concluded that they have limited utility in many...

Journal: :journal of agricultural science and technology 2010
s. s. hashemi m. baghernejad h. khademi

gypsiferous soils occur in xeric, ustic, and aridic moisture regimes. environmental conditions affect the mode of gypsum formation. gypsiferous soils in fars province, southern iran, are found in piedmont plains, flood plains, and alluvial plains. the objective of this work was to investigate the micromorphology of gypsum crystals formed under different soil moisture regimes. the results indica...

ژورنال: علوم آب و خاک 2012
روح اله رضایی ارشد, , علیرضا جعفرنژادی, , غلامعباس صیاد, , مسعود مظلوم, , مهدی شرفا, ,

Direct measurement of soil hydraulic characteristics is costly and time-consuming. Also, the method is partly unreliable due to soil heterogeneity and laboratory errors. Instead, soil hydraulic characteristics can be predicted using readily available data such as soil texture and bulk density using pedotransfer functions (PTFs). Artificial neural networks (ANNs) and statistical regression are t...

Abdolreza Bahremand Adel Sepehri Hossein Barani Manijeh Tavan Seid Ali Hoseini

Infiltration rate of water into the soil depends on the factors such as rock and litter cover, canopy cover, rainfall intensity, coarse material, land slope, soil texture and amount of initial soil moisture. The most important factors that are effective in the water infiltration rate of rangelands are livestock trampling and vegetation reduction due to the overgrazing. In present study, through...

Journal: :زمین شناسی اقتصادی 0
فاطمه هرمزی نژاد فاطمه راست منش علیرضا زراسوندی

introduction soil plays a vital role in human life as the very survival of mankind is tied to the preservation of soil productivity (kabata- pendies and mukherjee, 2007). the purpose of this study is the assessment of heavy metal contamination (zn, mn, pb, fe, ni, cr) of the soil around the khuzestan steel complex. materials and methods for this purpose, 13 surface soil samples (0-10 cm) were t...

Journal: :پژوهش آب در کشاورزی 0

designing and scheduling of drip irrigation systems are often done without enough information about water distribution in the soil. due to tillage operations and crop production practices, agricultural soils can be considered as two layered soils with different bulk densities. the top soil layer has a lighter texture than the sub soil layer. in this research, the development of the wetting fron...

1998
F. FeÂ

Large-scale simulation of the soil-derived dust emission in semi-arid regions needs to account for the in ̄uence of the soil moisture on the wind erosion threshold. Soil water retention consists of molecular adsorption on the soil grain surface and capillary forces between the grain. Interparticle capillary forces (characterized by the moisture tension) are the main factor responsible for the in...

2012
F. William Simmons Emerson D. Nafziger

Soil is one of our most precious natural resources. Proper soil management is a key to sustainable agricultural production. Soil management involves six essential practices: proper amount and type of tillage, maintenance of soil organic matter, maintenance of a proper nutrient supply for plants, avoidance of soil contamination, maintenance of the correct soil acidity, and control of soil loss (...

Journal: :journal of rangeland science 2012
maedeh yousefian khadijeh mahdavi mohammad mahdavi reza tamartash

livestock grazing is one of the most important kinds of land usage that has a high potential to decrease or increase carbon storage in rangeland ecosystem. this research was investigated the effects of enclosure on soil carbon storage in a rangeland with dominant plants of artemisia aucheri. hence, two rangelands of enclosure (shahtappeh-chah mahmood) and no enclosure (chiro) were chosen in sem...

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