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991.
西北戈壁荒漠区生态环境十分脆弱,以风蚀为主的水土流失非常严重;随着经济的发展该区域的道路建设也在加速发展,建设项目和生态环境保护一直是一对难以解决的矛盾,也是长期以来人们一直关注的焦点问题。针对上述问题对兰新铁路"百里风区"提速改建工程项目的水土流失及防治措施进行了探讨和研究。 相似文献
992.
水城县严重侵蚀地段不同治理模式的水土保持功能研究 总被引:2,自引:0,他引:2
对贵州西部水城县严重侵蚀地段3种治理模式及对照的水土保持功能进行了研究。结果表明:3种治理模式的水土保持功能大小顺序为模式Ⅲ>模式Ⅱ>模式Ⅰ,其土壤容重分别比对照减少了37.6%,21%和26.6%;土壤饱和持水量比对照增加了82%,43.5%,61.7%;土壤通气度是对照的2.26,1.44,1.16倍。抗侵蚀能力是对照的3.16,2.67,2.06倍。模式Ⅲ渗透性最强,其初渗速度和稳渗速度分别是对照的1.87和2.10倍,是模式Ⅱ的1.05和1.34倍,是模式Ⅰ的1.45和1.62倍。模式Ⅲ的枯落物层持水能力最强,为11.07 t/hm~2,分别是模式Ⅱ的1.26倍、模式Ⅰ的1.98倍。 相似文献
993.
XU Guang-Bo FU Wei-Jie WEI Tie-Zheng LI Gui-Hu LIANG Yun-Jiang QUAN Ming-Dao YANG Shu-Rong 《土壤圈》1997,7(4):355-360
A 5-year study on the soil ecological environment of matsutake(Tricholoma Matsutake)growing areas near Changbai Mountains showed that several factors,such as climate,parent material,organism and landform,which form the soil ecosystem provided sutable ecological environment for the formation and growth of matsutake How to improve the construction and function of the soil ecosystem in order to utilize the natural resource continumously was also studied. 相似文献
994.
995.
重庆酸性紫色土马铃薯的高产优质与养分平衡 总被引:2,自引:0,他引:2
Over a period of two years,field experiments were conducted on four silty loam soils grown with foliar vegetable crops inculding Chinese cabbage(Brassica pekingensis Rupr.,cv.Lu-Bai 3),autumn greens (B.chinensis L.,cv.Piao-Geng-Bai),winter greens(B.var.rosularis Tsen et Lee,cv,You-Dong-Er),and summer greens(B.chinensis L.,cv.Zao-Shu5),respectively,Each eperimpent included one CK treatment without K,N and Pfertilizers applied,and four treatments with from low to high doses,0-300 kg hm^-2 for Chinese cabbage,0-150 kg hm^-2 for autumm and winter greens and 0-180 kg hm^-2 for summer greens,of K fertilizers in the form of sulfate of potash(SOP)applied together with N and P fertlizers,One treatment of K fertilizer in the form of muriate of potash(MOP) applied at high levels(150 or 180 g hm^-2)together with N and P fertilizers was included in the experiments of autumn,winter and summer greens ,respectively,in order to compare the effcts of SOP and MOP ,The market yields of the tested crops incresaed significantly with the increasing rate of K application.The crops supplied with K fertilizers yielded more stably as the CV% of their yields decreased with the rate of K application.K fertilization increased not only K contents but also the amounts of N ,P and K absorbed in shoots of autumn,winter and summer greens,which were atatistically significantly correalted to their yields.In can aslo be found that potassium improved the quality of the foliar vegetable crops as their dry mater contents were generally increased and Vc contents obviously increased and nitrate contents markedly decreased ,As compared to MOP,SOP was more effective on the yields and quality of autumn,winter and summer greens at the high levels of fertilization. 相似文献
996.
X-ray photoelectron spectroscopy(XPS) was applied to examine the N structures of soil humic substances and some of their analogues.It was found that for soil humic substances XPS method gave similar results as those obtained by ^15N CPMAS NMR (cross-polarization magic-angle spinning nuclear magnetic resonance) method.70%-86% of total N in soil humic substances was in the form of amide,and 6%-13% was presented as ammes,with the remaining part as heterocyclic N.There was no difference in the distribution of the forms of N between the humic substances from soils formed over hundreds or thousands of years and the newly formed ones.For fulvic acid from weathered coal and benzoquinone-(NH4)2SO4 polymer the XPS results deviated significantly from the ^15N CPMAS NMR data. 相似文献
998.
Moderate grazing by cattle increases the heterogeneity of soil and vegetation. This has been suggested as an ecologically sustainable mean of managing natural environments endangered by tree encroachment, such as heathlands. Our study was performed to test the impact of grazing intensity on soil macroinvertebrate communities in heterogeneous landscapes in a private property eligible to the Natura 2000 European Network of Special Protection Areas within the Brenne Natural Regional Park (Indre, France). We sampled macroinvertebrates along a broken line crossing 5 different land-use types, from pasture to pine forest, passing through a besom heath (Erica scoparia) heathland at 3 levels of cattle pressure. We hypothesized that: i) litter-dwelling (mostly arthropods and mollusks) and soil-dwelling macroinvertebrates (mostly earthworms) would respond in an opposite manner to various grazing intensities, and ii) intermediate cattle pressure (pastured heath) would increase soil and community heterogeneity. The results supported the first hypothesis, which was explained by land-use impacts mediated by soil properties. However, our results supported only partly the second hypothesis since maximum dissimilarity (whether in the composition of soil macroinvertebrate communities or in soil features) was observed in only one out of the two pastured heaths where cattle pressure was intermediate. 相似文献
999.
黄土高原沟壑区土壤侵蚀评价指标体系——以中国王东沟流域为例 总被引:19,自引:0,他引:19
The Wangdonggou Watershed on the Loess Plateau in China was selected as the study area to develop a model for soil erosion assessments. Using the data collected at 20 sampling sites all tentatively selected indicators were assessed against their corresponding erosion intensity through a correlation analysis. Eight highly correlated indicators were then chosen for the soil erosion assessment. In addition, threshold limits to delineate the class size for these indicators and weights to rank them were determined. Next, a grading model incorporating the selected indicators class rating and their associated weights was developed and verified by an on site evaluation of the soil erosion intensity in the study area. Results of the verification showed that the overall accuracy of the indicator system for assessing soil erosion in the Loess Plateau gully regions could reach 85%. 相似文献
1000.
关于土地开发整理项目水土保持有关问题的探讨 总被引:4,自引:1,他引:4
防治水土流失是土地开发整理项目的重要内容。土地开发整理项目本身是一项水土保持工程,其是否需要水土保持方案,如何编制是亟待解决的科学与生产问题。从分析其自身特点入手,从现状与法律的规定性两方面对此问题进行了探讨,认为把水土保持方案设计的思路渗透到土地整理开发项目的相关设计中是目前解决该问题的最佳办法,并以山区、风沙区和丘陵区的3个项目为例进行了阐述。 相似文献