Results 21 to 30 of about 1,125 (129)

Gradient distributions of nitrogen and organic carbon in the soils from inland to tidal flat in the Yellow River Delta [PDF]

open access: yes, 2014
黄河三角洲是我国典型的通过黄河冲积泥沙填海造陆形成的近代沉积区。区域受到黄河冲积、沉积等自然过程和农业耕种熟化等人类活动的双重影响。本研究通过在黄河三角洲地区内陆到河口海湾不同距离采集典型土壤类型剖面发生层样品,探讨土壤有机碳、总氮等生源要素的空间分布规律,为阐明我国典型海岸带地区陆源碳、氮的输送及循环特征提供基础依据。研究结果表明,黄河三角洲内陆与河口地区呈现出完全不同的土壤碳、氮分布规律。表层土壤碳、氮含量在黄河沿岸及三角洲南部均表现出由陆向海逐级递减的空间分布特征 ...
李远   +4 more
core   +1 more source

Nutrient Characteristics and Factors Influencing Surface Soil with Gully Erosion on Sloping Farmland for Low Hilly Terrain in Black Soil Area [PDF]

open access: yes, 2023
[Objective] The soil nutrient characteristics and influencing factors of surface soil gully erosion for low hilly terrain in the black soil area were studied in order to provide data and theoretical support for the rational use of land resources ...
He Xuyang   +7 more
core   +1 more source

湘中山地土壤线虫(Nematoda)生态地理群的研究 [PDF]

open access: yes, 1992
作者对湖南南岳衡山和长沙岳麓山土壤线虫进行了两年多的定位研究,共获得18511条土壤线虫标本.经分类鉴定,计有24个种 ...
伍惠生, 张友梅, 王振中
core  

膜下滴灌条件下绿洲棉田土壤水分运动数值模拟 [PDF]

open access: yes, 2007
应用非饱和土壤水运动理论,建立膜下滴灌条件下土壤水分运动二维数值模拟模型,研究了田间层状土壤在膜下滴灌条件下土壤水分运动特征。应用不同小区不同灌水处理的实测值与模拟值进行对比,同时对模型做了精度分析,结果表明符合精度要求,这说明所建立的模型能客观地反映实际土壤条件下的水分运动情况。研究结果表明:土壤剖面30~40 cm粘土层使土壤水分运动具有很大的差异,0~30 cm变化明显,而40 cm以下土壤水分运动的变化较小。膜下滴灌应该采取灌水量小 ...
串志强, 方怡向, 盛钰, 赵成义
core  

Testing GLEAMS for Nitrate Leaching Modeling in an Agricultural Catchment of Southeast China [PDF]

open access: yes, 2007
利用我国东南亚热带地区农业小流域不同土地利用方式的硝氮渗漏淋失实测数据检验了GLEAMS(Groundwater Loading Effects of Agricultural Management Systems)模型在该地区的适用性。通过现场试验和实地调查并结合模型手册,获取模型所需的水文和营养盐参数,参考模型参数的敏感性分析结果对模型进行调试。结果表明模型对水稻田除外的其它土地利用方式的硝氮渗漏淋失模拟效果较好。水稻田渗漏模拟效果差的主要原因在于模型的水分平衡方程不能反应水稻田长期淹水的实际情况 ...
徐玉裕   +3 more
core  

Dynamic Simulation of Soil Moisture Under Typical Land Preparation in Semi-arid Loess Area Using HYDRUS-1D Model [PDF]

open access: yes, 2023
[Objective] The dynamic characteristics of soil moisture under different land preparation measures were analyzed in order to provide a scientific basis for assessing the eco-hydrological benefits of slope land preparations and for promoting vegetation ...
Dong Hongxia, Wei Qiang, Zhang Qindi
core   +1 more source

Effects of Disturbance Modes on Vegetation and Soil in Typical Grassland Area [PDF]

open access: yes, 2023
[Objective] The effect of different disturbance modes on soil physical and chemical properties and vegetation characteristics of typical grassland areas in Inner Mongolia were analyzed in order to provide a scientific basis for restoring the ecological ...
Cha Na   +6 more
core   +1 more source

Research on Bamboo Riparian Buffer Ecosystems for Diffuse Pollution Prevention [PDF]

open access: yes, 2010
进入农业系统的过量氮(N)、磷(P)极易通过地表径流或地下潜流、渗漏及农田排水进入水环境,引发水体富营养化。具有一定群落结构的河岸植被土壤系统内部具有较大的生物生存空间和相互作用区域,其间生物地球化学联合机制,可以减缓径流、捕获泥沙、截断或去除地表径流、壤中流或渗漏水及浅层地下水中的氮磷等元素,有效改善受纳水体的水质。了解河岸植被土壤系统削减污染物和净化水质的机制及其影响因素,有助于加强对河岸带的管理和重建工作,为防治面源污染提供科学依据。 本文采用土壤剖面渗透水分层采集装置 ...
方婧
core  

Distribution Pattern of Cadmium in the Profile of Shallow Fissure Soil and Its Influencing Factors in Karst Areas with High Geological Background [PDF]

open access: yes
[Objective] To study the vertical distribution pattern of cadmium (Cd) in shallow karst fissure soil, analyze the impacts of various factors on the distribution of Cd in fissures, and provide a scientific basis for future research on the distribution ...
CAI Huayin   +6 more
core   +1 more source

Distribution Characteristics of Phosphor and Sulfur in Different Wetland Soils of the Yellow River Delta [PDF]

open access: yes, 2010
以黄河口滨岸潮滩湿地为研究对象,研究了不同植被群落覆盖下湿地土壤中磷、硫的变化特征及其储量状况。结果表明,植被群落的变化能够影响土壤中磷、硫的含量,但影响程度不同。沿植物群落演替方向,土壤全磷含量差异不显著,变异系数较小,而全硫含量受影响显著,呈“S“型波动变化;在垂直分布特征方面,全磷的差异程度不大,表明土壤中磷含量主要取决于成土母质,相对而言,硫的垂直分布特征存在较大差异,大部分采样点的变异系数在10%以上,属中等变异,其分布特征主要受制于土壤有机质的分布 ...
孙万龙   +3 more
core  

Home - About - Disclaimer - Privacy