نتایج جستجو برای: layer soil

تعداد نتایج: 456925  

Journal: :آب و خاک 0
جلال حیدری شجاع قربانی دشتکی فایز رئیسی پژمان طهماسبی

annual fires might change many soil physical properties in semi steppe rangeland.the objective of this study was to investigate the impact of fire on soil physical properties and soil water infiltration parameters in semi-steppe rangeland of karsanak region in chaharmahal and bakhtiari province. therefore, several sites were chosen which were affected by fire at three, two and one years prior t...

2015
Lisa Kellman Amy Myette Hugo Beltrami Lucas C.R. Silva

Forest harvesting induces a step change in the climatic variables (temperature and moisture), that control carbon dioxide (CO2) production arising from soil organic matter decomposition within soils. Efforts to examine these vertically complex relationships in situ within soil profiles are lacking. In this study we examined how the climatic controls on CO2 production change within vertically di...

2011
Fan Yang Guangxin Zhang Xiongrui Yin Zhijun Liu

The objectives of this study were to investigate the degree of spatial variability and variance structure of salinization parameters using classical and geostatistical method in Songnen Plain of China, which is one of largest saline-sodic areas in the World, and to analyze the relationship between salinization parameters, including soil salinity content (SC), electrical conductivity (EC), sodiu...

Journal: :Bulletin of environmental contamination and toxicology 2008
G H N Farahani Ismail Bin Sahid Zuriati Zakaria Aini Kuntom Dzolkifli Omar

The downward movement of carbofuran in two Malaysian soil types was studied using soil columns. The columns were filled with disturbed and undisturbed soils of either the Bagan Datoh soil (clay) or the Labu soil (sandy clay). The average total percentage of carbofuran in the leachate of the undisturbed Labu soil after 14 days of watering (80.8%) was approximately similar to that of the total am...

2014
Saad Abdulrahman Al-Hamed Mohamed Fouad Wahby Abdulwahed Mohamed Aboukarima

An artificial neural network (ANN) model was employed to predict the soil cohesion and soil internal friction angle. The soil samples were collected from different cultivated sites in seven regions in Saudi Arabia. Direct shear box method was used to determine soil cohesion and soil internal friction angle. The input factors to ANN model were soil dry density, soil moisture content and soil tex...

Journal: :Journal of environmental radioactivity 2010
Noriko Yamaguchi Masashi Nakano Rieko Takamatsu Hajime Tanida

The transformation of inorganic iodine (I(-) and IO(3)(-)) incubated in soils with varying amounts of organic matter (Andosols from the surface layer of an upland field and forest, as well as Acrisols from surface and subsurface layers of an upland field) was investigated by using the iodine K-edge X-ray absorption near-edge structure (XANES). After 60d of reaction, both I(-) and IO(3)(-) were ...

2005
W. Ruan J. Liu F. P. Dawalibi R. D. Southey

-This paper discusses and compares HVDC ground electrode design methods in various soil structures. A number of cases are selected based on existing HVDC ground electrodes in order to compare the conventional simplified design method (Method A) with a more advanced grounding design method using a specialized engineering software (Method B). Various soil structures considered include horizontall...

Journal: :پژوهش های زراعی ایران 0

introduction phosphorus (p) is an essential element in crop nutrition, which can be growth limiting or an environmental contaminant, if present in excess. on the other hand, tillage practices have a direct effect on behavior and availability of soil p. since, application of different tillage methods lead to different patterns of soil phosphorus distribution, hence p fertilizer needs and p avail...

2013
McHenry

Organic farming systems still depend on intensive, mechanical soil tillage. Frequent passes by machinery traffic cause substantial soil compaction that threatens soil health. Adopting practices as reduced tillage and organic matter retention on the soil surface are considered effective ways to control soil compaction. In tropical regions, however, the acceleration of soil organic matter decompo...

2000
Raphaël J. Manlay Patrice Cadet Jean Thioulouse Jean-Luc Chotte

Relationships between soil characteristics, various forms of soil organic matter, microbial biomass and the structure of phytoparasitic nematode populations were investigated in six fallow fields aged from 1 to 26 years in the West African Savanna (WAS) belt in southern Senegal. Soil sampling was performed along two transects in each field. Herbaceous biomass and soil physical, chemical and bio...

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