Results 51 to 60 of about 1,065 (140)

Sustainable agriculture: a case study of contour hedgerows in Zigui County, Hubei Province, China. [PDF]

open access: yes, 2004
Tang Chi Wai.Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.Includes bibliographical references (leaves 104-121) and index.Abstracts in English and Chinese.Abstract --- p.i摘要 --- p.iiiAcknowledgements --- p.vTable of Contents --- p.viiList ...

core  

岩溶区免耕和翻耕措施对裸坡耕地产流产沙过程的影响

open access: yesShuitu Baochi Xuebao, 2017
为揭示不同耕作措施对喀斯特地区坡耕地产流产沙的影响,采用独立设计土仓、室内人工模拟降雨的方法,通过设定一定雨强下研究不同耕作措施对西南岩溶区裸坡耕地径流与土壤流失特征。结果表明:雨强为63 mm/h,坡度小于10°时,翻耕措施能够加快地下孔隙的产流时间,而免耕能够滞缓其产流,翻耕的产沙量为免耕的66%;当坡度大于10°时,翻耕措施能够延缓地下孔隙的产流时间,而免耕则加速其产流,翻耕的产沙量分别为免耕的16%和6%。雨强为100 mm/h,坡度小于10°时,随着坡度的增大 ...
方荣杰, 朱晓锋, 韩
doaj  

Evolution Characteristics of Soil and Water Conservation Carbon Pool and Its Carbon Sink Potential in Typical Small Watershed of the Loess Plateau [PDF]

open access: yes
[Objective] To investigate the evolution of soil carbon pool under catchment scale integrated soil and water conservation measures and evaluate the potential of soil and water conservation carbon sink. [Methods] Typical small watershed for soil and water
DONG Pengbei   +5 more
core   +1 more source

坡耕地等高反坡阶整地年限对土壤改良和玉米产量的影响

open access: yesShuitu Baochi Xuebao, 2022
为探究等高反坡阶整地改良红壤坡耕地土壤质量的效果, 利用田间定位试验, 以滇中昆明松华坝迤者流域坡耕地试验区已实施等高反坡阶整地措施3(CRT 3), 7(CRT 7), 9(CRT 9)年的样地及原状坡耕地(CK)为研究对象, 结合各样地玉米产量探明实施年限对土壤结构、肥力和酶活性特征的影响。结果表明: 等高反坡阶整地年限显著改善坡耕地土壤的物理性状, 呈现黏粒、粉粒、总团聚体和总孔隙度显著增加, 砂粒和容重显著降低; 提高了土壤肥力, 其中全氮、全磷、全钾、速效磷、速效钾含量和含水量显著提高 ...
刘晓微   +5 more
doaj  

The Cultural Change of Elunchun Nationality and the Thought Provoked by the Transformation of Economy [PDF]

open access: yes, 2010
The Elunchun nationality is one of the Chinese minorities. Statistics shows that there are only 8196 Elunchun people in 2000. This paper provides a systematic analysis on the present existence and development conditions of the Elunchun nationality and ...
LIU, Xiao-chun
core   +2 more sources

等高耕作对不同坡度坡面土壤侵蚀过程的影响

open access: yesShuitu Baochi Xuebao, 2023
等高耕作是一种典型的农业耕作措施,通过影响坡面填洼、入渗等进而影响坡耕地坡面土壤侵蚀过程。通过人工模拟降雨试验,设计降雨强度(90 mm/h)、5个地表坡度(3°,5°,10°,15°,20°)以及2种坡面处理(等高耕作和平整坡面),对径流强度、侵蚀率、径流含沙量、减流减沙效益等指标进行综合对比分析,与平整坡面进行比较,探究了黄土高原坡耕地等高耕作措施对坡面土壤侵蚀过程的影响。结果表明:(1)与平整坡面相比,等高耕作明显延缓坡面初始产流时间,使初始产流时间延迟11.58~31.91 min,随着坡度增大,
陆淑宁   +5 more
doaj  

不同土地利用方式对岩溶山地土壤团粒结构的影响

open access: yesShuitu Baochi Xuebao, 2001
研究了 5种利用方式对岩溶山地土壤水稳定性团聚体的影响。结果表明 :>0 .2 5 mm水稳定性团聚体为草坡 >林地 >弃耕地 >果园 >耕地 ;林地、草坡的土壤表层和亚表层水稳定性团聚体以 >2 mm为主 ,而果园、弃耕地、耕地土壤 >2 mm的水稳定性团聚体较小。水稳定性团聚体以及团聚的水稳性均与有机质的含量呈正相关 ,林地、草坡开垦后 ,土壤有机质分解加快或补充减少是土壤团聚体水稳定性下降及数量减少的主要原因。坡耕地退耕后 ,土壤团聚体可得到恢复。
李阳兵, 谢德体
doaj   +2 more sources

近景摄影测量技术在坡耕地土壤侵蚀速率研究中的应用

open access: yesShuitu Baochi Xuebao, 2018
以5°,10°,20°的紫色土坡耕地为研究对象,分别进行5,10,15次强度的模拟耕作试验,在此基础上采用60 L/min的流量进行3轮放水冲刷试验,采用近景摄影测量技术监测试验前后紫色土坡耕地小区的地形变化,通过生成高精度DEM数据计算土壤流失体积,并采用插钎法测量土层深度变化,验证近景摄影测量技术测定地形变化的准确度,进而推算不同坡度条件下的紫色土坡耕地耕作侵蚀速率和水力侵蚀速率。结果表明:(1)采用近景摄影测量技术能够准确监测地形变化,其测算结果与插钎法的结果比较接近 ...
杨, 苏正安
doaj  

Analysis of the Dynamic Relationship between Runoff and Phosphorus Transport in the Menglianggu Small Watershed [PDF]

open access: yes
[Objective] To investigate the characteristics of runoff-phosphorus loss hysteresis relationship under different rainfall types. [Methods] This study focused on the Menglianggu small watershed in the rocky mountainous area of northern China.
HU Yanxia   +5 more
core   +1 more source

西南高山峡谷区人为耕作扰动对典型坡耕地坡面坡形和微地形的影响

open access: yesShuitu Baochi Xuebao
目的 为探明西南高山峡谷区长期不同耕作扰动方式对耕地坡面地形特征的影响。方法 选取该区域典型坡耕地(坡度为15°,坡长为20 m)为研究对象,通过顺坡耕作与等高耕作方式连续耕作50次,结合测针法与3 D激光扫描技术,探究2种长期耕作扰动方式下坡面坡形和微地形特征的变化。结果 连续顺坡耕作50次后,坡形逐渐由线性坡向“”型复合坡演化,而等高耕作向“”型复合坡演化。连续耕作后,顺坡耕作和等高耕作导致上坡侵蚀范围分别占整个坡面的15%和11%,堆积范围分别占整个坡面的13%和6 ...
王嘉琦   +8 more
doaj  

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