نتایج جستجو برای: initial soil nitrate measuring

تعداد نتایج: 727529  

Journal: :کشاورزی (منتشر نمی شود) 0
پانته آ ‏رهبری دانشجوی کارشناسی ارشد آبیاری و زهکشی، دانشکده کشاورزی، دانشگاه تهران، تهران - ایران‏ سید جلال‎ ‎الدین جبلی استادیار مجتمع آموزشی ابوریحان، دانشگاه تهران، تهران - ایران‏ عبدالمجید ‏لیاقت دانشیار گروه آبیاری، دانشکده کشاورزی، دانشگاه تهران، تهران - ایران‏

the use of fertilizers in agriculture is a potential source of environmental pollution especially in ‎water quality and soil resources. the study of effective factors on water and nutrient transport ‎through soil profile is helpful for nutrient management to minimize adverse impacts on environment ‎and nitrate leaching below root zone. in this study, for assessing the nitrate transportation bel...

2006
B. J. Wienhold J. W. Doran

Soils perform a number of essential functions affecting management goals. Soil functions were assessed by measuring physical, chemical, and biological properties in a regional assessment of conventional (CON) and alternative (ALT) management practices at eight sites within the Great Plains. The results, reported in accompanying papers, provide excellent data for assessing how management practic...

ژورنال: علوم آب و خاک 2015
رسولی صدقیانی, میرحسن, اجلالی , سارا , اشرفی سعیدلو, ساناز ,

Earthworms are an important component of soil fauna because of their fundamental impact on soil physical, chemical and biological properties. To evaluate the effects of earthworms on some soil chemical properties as well as plant growth indicators, an experiment was carried out in a completely randomized design in greenhouse conditions. The first factor involved the presence or absence of earth...

In this work, hydrophobic silica aerogels were synthesized using sol-gel method and drying at ambient pressure. The surface morphology, pore size, and the presence of functional groups on the surface of the nanoparticles were analyzed using FE-SEM, TGA, FT-IR, and EDX, respectively. After calcination at 500 °C, the hydrophilic property of the adsorbents was evaluated by water contact angle meas...

2008

Our researches have been made on brown forest soil that had been used in long-term experiments set up according to specified fertilization system for over 30 years. We have chosen those experiment variants in which quantities of nitrogen fertilizers were gradually increased. The soil samples taken from 0 cm to 30 cm depth were used to determine biological indexes of nitrogen availability (aerob...

Journal: :تحقیقات نظام سلامت 0
حسن ایزانلو استادیار، مرکز تحقیقات آلاینده های محیطی و گروه مهندسی بهداشت محیط، دانشگاه علوم پزشکی قم، قم، ایران. طیبه رحیمی کارشناس مهندسی بهداشت محیط، مرکز تحقیقات آلاینده های محیطی و گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی قم، قم، ایران. محمدحسن محمودیان مربی، گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی قم، قم، ایران. محمد خزائی کارشناس ارشد مهندسی بهداشت محیط، گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی قم، قم، ایران. زینب یاوری کارشناس مهندسی بهداشت محیط، مرکز تحقیقات آلاینده های محیطی و گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی قم، قم، ایران. علیرضا عسگری مربی، گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی شاهرود، شاهرود، ایران. نجمه واعظی

background: one of the major sources of drinking water contamination is nitrate. nitrate concentrations of more than the standard levels (45mgl -1 based on nitrate) could cause methemoglobinemia in children. the aim of this study is to investigate the nitrate adsorption on granular ferric hydroxide (gfh). also in this study, the effect of factors such as initial concentration of nitrate, contac...

2002
L. Ruiz J. Molénat

In catchments with impervious bedrock, the nitrate concentrations in streamwater often show marked seasonal and small inter-annual variations. The inter-annual trends are usually attributed to changes in nitrogen inputs, due to changes in land use or in nitrogen deposition whereas seasonal patterns are explained in terms of availability of soil nitrate for leaching and of seasonality of nitroge...

2003
A. Moulin D. Derksen D. McLaren

A field study was conducted on hummocky terrain at the Manitoba Zero Tillage Association Research Farm near Brandon, Manitoba, Canada to determine the variability of crop yield as related to landscape position, soil properties, weed populations and plant disease. This information was used to develop a method for delineation of management units related to precision farming. Variable-rate fertili...

2018
Xiaofei Tian Chengliang Li Min Zhang Yongshan Wan Zhihua Xie Baocheng Chen Wenqing Li

Biochar application as a soil amendment has been proposed as a strategy to improve soil fertility and increase crop yields. However, the effects of successive biochar applications on cotton yields and nutrient distribution in soil are not well documented. A three-year field study was conducted to investigate the effects of successive biochar applications at different rates on cotton yield and o...

Journal: :Biochemical Society transactions 1992
M A Murcia A Vera F Garcia-Carmona

High nitrate concentrations in salads and vegetables have attracted increased attention. It is well know that nitrate can cause serious health problems to humans such as methemoglobinemia of infants 111. Under certain conditions, specially in the human body carcinogenic nitrosamines can be formed [2]. However, nitrate content of different types of vegetables fluctuates substantially with variet...

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