نتایج جستجو برای: 30 cm soil depth with 15 mgkg n

تعداد نتایج: 9860036  

ژورنال: مرتع 2023

Background and objectives: Organic carbon is one of the important parameters to determine soil fertility, and production ability and is a mind index for showing soil quality, especially in dry and semi-dry lands. The rangelands are composed of about 50 % of the world's lands and have more than 33 % of carbon reservoirs on earth. Considering the ranges as the most important terrestrial ecosystem...

2016
Boqi Liu Changcheng Mou Guoyong Yan Lijian Xu Siling Jiang Yajuan Xing Shijie Han Jinghua Yu Qinggui Wang

We conducted a snow depth 0 cm (non-snowpack), 10 cm, 20 cm, 30 cm and natural depth) gradient experiment under four quantities of nitrogen addition (control, no added N; low-N, 5 g N m(-2) yr(-1); medium-N, 10 g N m(-2) yr(-1); and high-N, 15 g N m(-2) yr(-1)) and took an-entire-year measurements of soil respiration (Rs) in Korean pine forests in northeastern China during 2013-2014. No evidenc...

2014
Kabindra Adhikari Alfred E. Hartemink Budiman Minasny Rania Bou Kheir Mette B. Greve Mogens H. Greve

Estimation of carbon contents and stocks are important for carbon sequestration, greenhouse gas emissions and national carbon balance inventories. For Denmark, we modeled the vertical distribution of soil organic carbon (SOC) and bulk density, and mapped its spatial distribution at five standard soil depth intervals (0-5, 5-15, 15-30, 30-60 and 60-100 cm) using 18 environmental variables as pre...

Journal: :Journal of nematology 1996
A W Johnson R D Wauchope D R Sumner

Recoverable fenamiphos in the soil and residue in squash following different simulated rainfall treatments after nematicide application were determined in a 2-year study. Efficacy of fenamiphos also was evaluated. Fenamiphos treatments (3 SC and 15 G) were broadcast (6.7 kg a.i./ha) over plots and incorporated into the top 15 cm of soil immediately before planting 'Dixie Hybrid' squash. Simulat...

Journal: :TheScientificWorldJournal 2007
Yvonne A Wood Mark Fenn Thomas Meixner Peter J Shouse Joan Breiner Edith Allen Laosheng Wu

We report the rapid acidification of forest soils in the San Bernardino Mountains of southern California. After 30 years, soil to a depth of 25 cm has decreased from a pH (measured in 0.01 M CaCl2) of 4.8 to 3.1. At the 50-cm depth, it has changed from a pH of 4.8 to 4.2. We attribute this rapid change in soil reactivity to very high rates of anthropogenic atmospheric nitrogen (N) added to the ...

ژورنال: علوم آب و خاک 2010
افیونی, مجید, شیرانی, حسین , حاج عباسی, محمدعلی , همت, عباس,

Tillage systems and organic manures could affect soil physical and mechanical properties. This study was conducted to investigate the impacts of two tillage systems including conventional tillage by moldboard plowing (plowing depth, 30 cm) and reduced tillage by disk plow (plowing depth, 15 cm) and three rates (0, 30 and 60 ton ha-1) of farmyard manure (FYM) on the soil penetration resistance u...

Journal: :Annals of botany 2013
Jianrong Wu Huancheng Ma Xingliang Xu Na Qiao Shitan Guo Fang Liu Donghua Zhang Liping Zhou

BACKGROUND AND AIMS Orchid mycorrhizas exhibit a unique type of mycorrhizal symbiosis that occurs between fungi and plants of the family Orchidaceae. In general, the roots of orchids are typically coarse compared with those of other plant species, leading to a considerably low surface area to volume ratio. As a result, orchids are often ill-adapted for direct nutrient acquisition from the soil ...

Journal: :پژوهش های علوم و فناوری چوب و جنگل 0

in order to assess the adaptation of elaeagnus angustifolia l. and fraxinus rotundifolia mill afforestation around tabriz international airport, the qualitative and quantitative characteristics of trees were measured in 96 experimental circular plots with a size of 300 m2. to study the edaphic effects of these species, nine samples were randomly collected from 0-10 cm and 10-20 cm depth of soil...

Journal: :Bulletin of environmental contamination and toxicology 2010
Z Z Yang Y F Li Y X Hou H Y Liang Z F Qin S Fu

37 PBDE congeners were analyzed at six different depths in two soil cores taken from a typical electronic waste polluted area in South China. The PBDEs were congregated in the surface layer (0-5 cm) of soil cores and were 29 times in MK and 18 times in NW higher than the second lower layers (5-10 cm). As a whole, the concentrations of PBDEs were decreased with the soil depth increased in two co...

Journal: :محیط زیست طبیعی 0
مقداد جورغلامی استادیار گروه جنگلداری، دانشکده منابع طبیعی، دانشگاه تهران، ایران

in forest harvesting, there is an ongoing trend to increase constantly the size, power and load of logging machines. this may cause soil degradation in forest ecosystems as the passes of these machines modify important soil structural characteristics. the present study was conducted to examine impact of skidding traffic, trail slope, traffic frequency, and soil depth on bulk density and soil co...

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