نتایج جستجو برای: layer soil

تعداد نتایج: 456925  

2016
Jiangbao Xia Ximei Zhao Yinping Chen Ying Fang Ziguo Zhao Haitao Shi

Groundwater is the main water resource for plant growth and development in the saline soil of the Yellow River Delta in China. To investigate the variabilities and distributions of soil water and salt contents at various groundwater level (GL), soil columns with planting Tamarix chinensis Lour were established at six different GL. The results demonstrated the following: With increasing GL, the ...

2006
AIHUI WANG XUBIN ZENG SAMUEL S. P. SHEN QING-CUN ZENG ROBERT E. DICKINSON

This paper intends to investigate the time scales of land surface hydrology and enhance the understanding of the hydrological cycle between the atmosphere, vegetation, and soil. A three-layer model for land surface hydrology is developed to study the temporal variation and vertical structure of water reservoirs in the vegetation–soil system in response to precipitation forcing. The model is an ...

2000
Michael Bonkowski Bryan Griffiths Charles Scrimgeour

In this study we simultaneously manipulated the patchiness of complex organic resources and the composition of microfaunal populations (protozoa and nematodes) in soil, to influence microbial mineralization processes and to elucidate the underlying mechanisms of nutrient acquisition from decomposing plant residues by ryegrass plants. Hotspot treatments of decreasing patchiness were established ...

2013
H Genet A D McGuire K Barrett A Breen E S Euskirchen J F Johnstone E S Kasischke A M Melvin A Bennett M C Mack T S Rupp A E G Schuur M R Turetsky F Yuan

There is a substantial amount of carbon stored in the permafrost soils of boreal forest ecosystems, where it is currently protected from decomposition. The surface organic horizons insulate the deeper soil from variations in atmospheric temperature. The removal of these insulating horizons through consumption by fire increases the vulnerability of permafrost to thaw, and the carbon stored in pe...

Journal: :Journal of environmental quality 2007
Joon Ki Yoon Xinde Cao Lena Q Ma

Phosphate rock (PR) and phosphoric acid (PA) are an effective combination of P sources for immobilizing Pb in contaminated soils. This column experiment examined the effectiveness of different application methods on Pb immobilization in a contaminated soil. Phosphate was applied at a P/Pb molar ratio of 4 with half as PR and half PA. While PR was mixed with the soil or placed as a layer, aqueou...

2016
Dongyan Liu Kanako Tago Masahito Hayatsu Takeshi Tokida Hidemitsu Sakai Hirofumi Nakamura Yasuhiro Usui Toshihiro Hasegawa Susumu Asakawa

Elevated concentrations of atmospheric CO2 ([CO2]) enhance the production and emission of methane in paddy fields. In the present study, the effects of elevated [CO2], elevated temperature (ET), and no nitrogen fertilization (LN) on methanogenic archaeal and methane-oxidizing bacterial community structures in a free-air CO2 enrichment (FACE) experimental paddy field were investigated by PCR-DGG...

2005
R. L. Raper E. B. Schwab S. M. Dabney

Soil compaction in the form of a hardpan layer restricts root growth and reduces crop yield throughout the Southeastern United States. However, the depth of this compacted soil layer varies significantly over landscapes. A sampling procedure was developed and evaluated to determine the depth of the hardpan layer in upland soils of Grenada silt loam soil type in this region. Cone index profiles ...

2014
Erik Grüneberg Daniel Ziche Nicole Wellbrock

The National Forest Soil Inventory (NFSI) provides the Greenhouse Gas Reporting in Germany with a quantitative assessment of organic carbon (C) stocks and changes in forest soils. Carbon stocks of the organic layer and the mineral topsoil (30 cm) were estimated on the basis of ca. 1.800 plots sampled from 1987 to 1992 and resampled from 2006 to 2008 on a nationwide grid of 8 × 8 km. Organic lay...

2016
Fan Yang Fenghua An Hongyuan Ma Zhichun Wang Xia Zhou Zhijun Liu Hongyan Li

Over three million hectares of salt-affected soils characterized with high salinity and sodicity caused serious land degradation in Songnen Plain, northeast China. Soil salinity–sodicity heterogeneous distribution under microtopography is usually influenced by several environmental factors. The side direction movement of soil water driven by water from depression is the key factor that aggravat...

2017
Hongzhi Zhang Aziz Khan Daniel K. Y. Tan Honghai Luo

There is a need to optimize water-nitrogen (N) applications to increase seed cotton yield and water use efficiency (WUE) under a mulch drip irrigation system. This study evaluated the effects of four water regimes [moderate drip irrigation from the third-leaf to the boll-opening stage (W1), deficit drip irrigation from the third-leaf to the flowering stage and sufficient drip irrigation thereaf...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید