نتایج جستجو برای: nitrogen leaching

تعداد نتایج: 127323  

2012
Alaa El-Sadek

The objective of this research is to control the nitrate-nitrogen concentration in surface water to 11.3 mg l (EU standards) and determine the exact nitrogen amount that has to be applied to achieve this limitation and calculate the corresponding plant uptake. The method used in this study is a combination between DRAINMOD-N model and Environmental Management for Agriculture (EMA), applying the...

2002
Egbert Matzner

Many forest ecosystems in Central Europe have reached the status of N saturation due to chronically high N deposition. In consequence, the NO3 leaching into groundand surface waters is often substantial. Critical loads have been defined to abate the negative consequences of the NO3 leaching such as soil acidification and nutrient losses. The steady state mass balance method is normally used to ...

2005
T. J. CENTNER J. E. HOUSTON A. G. KEELER C. FUCHS

Nonpoint source water pollution generated by agricultural production is considered a major environmental issue in the United States and Europe. One strategy in the United States has been to adopt various measures, called best management practices (BMPs), to reduce water pollution. Our research addresses legal institutions and the applied use of BMPs, and discusses compensatory payments to reduc...

2007
Shijuan Li Yeping Zhu

Based on the maize ecophysiological characteristics, the maize developping process-based cooperative models including growth model, developmental phase models, water balance model and nitrogen balance model etc. was built combined with the basic data such as variety characteristics, weather data, soil level and cultivation management with the technology support of system engineering method, cro...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1387

boron nitride semiconducting zigzag swcnt, $b_{cb}$$n_{cn}$$c_{1-cb-cn}$, as a potential candidate for making nanoelectronic devices was examined. in contrast to the previous dft calculations, wherein just one boron and nitrogen doping configuration have been considered, here for the average over all possible configurations, density of states (dos) was calculated in terms of boron and nitrogen ...

2010
Zhonghao Zhou Guojian Zhang Xiaomei Song Shuhan Du Gangcai Liu

The spread of vegetable production around Lhasa, Tibet, China, with high nitrogen fertiliser use may cause accelerated acidification which has consequences for soil productivity. In order to understand the different patterns of soil acidity in Lhasa, Tibet, China three patterns of land use were studied namely: grain, openfield vegetable, and greenhouse vegetable. Fertilizer application was high...

Series of Copper Ruthenium (Cu-Ru) bimetallic catalysts supported on γ-Al2O3 with different metal loading are prepared and investigated for catalytic wet air oxidation of ammonia to nitrogen. The ammonia decomposition activity was studied at three different temperatures i.e. 150oC, 200oC, and 230 oC and it is found that catalytic activity increases with the increase in temperature along with th...

S. E. Rezaei S. K. Sadrnezhaad,

Fe is an impurity in most leach liquors. Its coexistence with copper in leaching solution of chalcopyrite (CuFeS2) which is the most important mineral of copper creates major extraction problems. Hydrochloric acid dissolves both copper and iron during chloride leaching of this mineral. Separation of Fe from Cu is thus necessary to obtain pure copper. This paper presents a novel metho...

آقاعلیخانی, مجید , غلامحسینی, مجید , ملکوتی , محمدجعفر ,

In order to study the effect of various amounts of nitrogen (N) and Iranian natural zeolite on the quantitative and qualitative forage yield of winter canola (Brassica napus L.) in light soil, a field experiment was conducted on research farm of Tarbiat Modares University, Tehran, during 2006-2007. Treatments were arranged in the form of RCBD with 3 replications. The experimental treatments wer...

2017
Rebecca E. Shelton Krista L. Jacobsen Rebecca L. McCulley

Agroecosystem nitrogen (N) loss produces greenhouse gases, induces eutrophication, and is costly for farmers; therefore, conservation agricultural management practices aimed at reducing N loss are increasingly adopted. However, the ecosystem consequences of these practices have not been well-studied. We quantified N loss via leaching, NH3 volatilization, N2O emissions, and N retention in plant ...

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