نتایج جستجو برای: soil nitrogen percent 006

تعداد نتایج: 382998  

2014
Teresia Svensson Lars Högbom Karin Johansson

There is increasing evidence that forests and forest soil contribute to the signature of chlorine composition in water bodies. However, little is known about the potential effects of land management activities on chlorine biogeochemistry. This study examines the effects of previous nitrogen addition on chlorine chemistry in a Pinus sylvestris (L.) forest located in south-central Sweden (60°00 ...

Journal: :Global change biology 2014
John L Campbell Anne M Socci Pamela H Templer

The depth and duration of snow pack is declining in the northeastern United States as a result of warming air temperatures. Since snow insulates soil, a decreased snow pack can increase the frequency of soil freezing, which has been shown to have important biogeochemical implications. One of the most notable effects of soil freezing is increased inorganic nitrogen losses from soil during the fo...

2015
Huiyan Gao Luhua Yang

Field experiment was carried out to study on the spatial and temporal distribution of soil nitrate nitrogen at Ranzhuang water resources experiment station in Hebei piedmont plain from 2011 to 2012. The results show that nitrate nitrogen content varies in sinusoidal curve at shallow tilth soil and shows in “W” shape at deep soil profile during the wheat-maize rotation period. Nitrate nitrogen i...

Journal: :Biochemical Society transactions 2011
Tobias Rütting Dries Huygens Jeroen Staelens Christoph Müller Pascal Boeckx

To obtain an in-depth understanding of soil nitrogen dynamics, it is necessary to quantify a variety of simultaneously occurring gross nitrogen transformation processes. In order to do so, most studies apply 15N in a disturbed soil-microbial-root system and quantify gross rates based on the principles of 15N isotope dilution. However, this approach has several shortcomings. First, studying dist...

Journal: :آب و خاک 0
حلاج نیا حلاج نیا حق نیا حق نیا لکزیان لکزیان رمضانیان رمضانیان

elevated atmospheric carbon dioxide and other green house gases have increased the earth temperature in recent century, which it affects all biochemistry cycles in soils. to examine the effect of atmospheric co2 concentration and temperature on n forms in soil solution in a calcareous soil, an experiment was conducted in a completely randomized design with factorial arrangement in the laborator...

2017
Pengcheng Nie Tao Dong Yong He Fangfang Qu

Soil nitrogen content is one of the important growth nutrient parameters of crops. It is a prerequisite for scientific fertilization to accurately grasp soil nutrient information in precision agriculture. The information about nutrients such as nitrogen in the soil can be obtained quickly by using a near-infrared sensor. The data can be analyzed in the detection process, which is nondestructive...

2017
Yong Zhang Shikui Dong Qingzhu Gao Shiliang Liu Hasbagan Ganjurjav Xuexia Wang Xukun Su Xiaoyu Wu

To understand effects of soil microbes on soil biochemistry in alpine grassland ecosystems under environmental changes, we explored relationships between soil microbial diversity and soil total nitrogen, organic carbon, available nitrogen and phosphorus, soil microbial biomass and soil enzyme activities in alpine meadow, alpine steppe and cultivated grassland on the Qinghai-Tibetan plateau unde...

2005
K. Sharma. S. Bajracharya Atreya

Soil nutrient depletion is a major concern in terms of resource utilization and optimization of production in the middle hills of Nepal. Soil and nutrient losses from agricultural land is responsible for pollution of surface waters and this reduces the productive capacity of land. A field experiment was initiated in May 2001 on acidic sandy loam soil in Kavre district; Nepal to investigate the ...

2011
Yolima Carrillo Becky A. Ball Mark A. Bradford Carl F. Jordan Marirosa Molina

Plant chemical composition and the soil community are known to influence litter and soil organic matter decomposition. Although these two factors are likely to interact, their mechanisms and outcomes of interaction are not well understood. Studies of their interactive effects are rare and usually focus on carbon dynamics of litter, while nutrient dynamics in the underlying soil have been ignore...

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