نتایج جستجو برای: nitrate leaching

تعداد نتایج: 42222  

1996
N. Gutierrez

Cement-based wasteforms are among the most commonly used waste disposal and site remediation options. However, concrete knowledge of the processes controlling long-term performance of the wasteforms is lacking. This research evaluates the effect of carbonation on cementitious wasteforms. Wasteforms were reacted with carbon dioxide for a prolonged period and then subjected to leaching tests. Ion...

2004
Andreas Renck Johannes Lehmann

SOILS in the humid tropics are known for their low retention capacity of nutrients and high susceptibility to leaching (Van Wambeke, 1992). Nitrogen is particularly susceptible to leaching losses since mineralization and nitrification both proceed very rapidly under humid tropical conditions and because nitrate is very mobile in most soils. In central Amazonian Oxisols, a large accumulation of ...

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...

2012
Sandra Menasha

Nitrogen management practices have an effect on crop yields but they can also have a negative impact on the environment. Practices such as banding fertilizer and/or split-applying total nitrogen needs per acre offer a more efficient use of nitrogen by significantly reducing nitrate leaching potential. Heavy rains occurring when plants are small and nitrogen demands are low can also increase nit...

M. Heidarpour S. F. Mousavi Sh. ANSARI

ABSTRACT-Nowadays farmers often use N-fertilizers to increase crop yield, but they lost quickly by leaching causes environmental contaminations that reported as most important source of pollutant. Although biofilters are useful for removing nitrate from drainage water, but many researches show that they need an external carbon source to sustain denitrification. Many researchers study on differe...

Journal: :Environmental pollution 2010
Cecilia Akselsson Salim Belyazid Sofie Hellsten Malin Klarqvist Gunilla Pihl-Karlsson Per-Erik Karlsson Lars Lundin

Nitrogen leaching from boreal and temporal forests, where normally most of the nitrogen is retained, has the potential to increase acidification of soil and water and eutrophication of the Baltic Sea. In parts of Sweden, where the nitrogen deposition has been intermediate to high during recent decades, there are indications that the soils are close to nitrogen saturation. In this study, four di...

Journal: :پژوهش آب در کشاورزی 0
عباس ستوده نیا استادیار گروه مهندسی آب دانشگاه بین‏المللی امام خمینی (ره). الهام نوروزپوراصل دانشجوی کارشناسی ارشد آبیاری و زهکشی دانشگاه بین‏المللی امام خمینی (ره). پیمان دانش کار آراسته استادیار گروه مهندسی آب دانشگاه بین‏المللی امام خمینی (ره).

pipe drain installation depth is one of the most important design parameters, which has a key role in the drained water volume and quality. in this research, the effect of pipe drain installation depth was investigated by using a physical laboratory model. drains were installed at 0.25, 0.5 and 0.85 m deep in a cubical box with dimensions of 1*0.5*1 meter filled with a sandy loam soil. nitrate,...

2013
An Cheng Sao-Jeng Chao Wei-Ting Lin

Leaching of calcium ions increases the porosity of cement-based materials, consequently resulting in a negative effect on durability since it provides an entry for aggressive harmful ions, causing reinforcing steel corrosion. This study investigates the effects of leaching behavior of calcium ions on the compression and durability of cement-based materials. Since the parameters influencing the ...

Journal: :The Science of the total environment 2016
Bruno Basso Benjamin Dumont Davide Cammarano Andrea Pezzuolo Francesco Marinello Luigi Sartori

Agronomic input and management practices have traditionally been applied uniformly on agricultural fields despite the presence of spatial variability of soil properties and landscape position. When spatial variability is ignored, uniform agronomic management can be both economically and environmentally inefficient. The objectives of this study were to: i) identify optimal N fertilizer rates usi...

2013
F. Cui X. Zheng C. Liu K. Wang Z. Zhou

Contemporary agriculture is shifting from a single-goal to a multi-goal strategy, which in turn requires choosing best management practice (BMP) based on an assessment of the biogeochemical effects of management alternatives. The bottleneck is the capacity of predicting the simultaneous effects of different management practice scenarios on multiple goals and choosing BMP among scenarios. The de...

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