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Soil degradation: a global problem endangering sustainable development 被引量:6
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作者 Chen Jie Chen Jing-zhang +1 位作者 Tan Man-zhi Gong Zi-tong 《Journal of Geographical Sciences》 SCIE CSCD 2002年第2期120-129,共10页
Soil degradation, defined as lowering and losing of soil functions, is becoming more and more serious worldwide in recent decades, and poses a threat to agricultural production and terrestrial ecosystem. It is estimat... Soil degradation, defined as lowering and losing of soil functions, is becoming more and more serious worldwide in recent decades, and poses a threat to agricultural production and terrestrial ecosystem. It is estimated that nearly 2 billion ha of soil resources in the world have been degraded, namely approximately 22% of the total cropland, pasture, forest, and woodland. Globally, soil erosion, chemical deterioration and physical degradation are the important parts amongst various types of soil degradation. As a natural process, soil degradation can be enhanced or dampened by a variety of human activities such as inappropriate agricultural management, overgrazing, deforestation, etc. Degraded soil means less food. As a result of soil degradation, it is estimated that about 11.9-13.4% of the global agricultural supply has been lost in the past five decades. Besides, soil degradation is also associated with off-site problems of sedimentation, climate change, watershed functions, and changes in natural habitats leading to loss of genetic stock and biodiversity. Therefore, it is essential to combat soil degradation at different levels and scales worldwide, not only for food security and ecological health, but also for the guarantee of global sustainable development. 展开更多
关键词 soil soil degradation EROSION food security sustainable development
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Assessment of soil degradation and chemical compositions in Rwandan tea-growing areas 被引量:2
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作者 Jean de la Paix Mupenzi Lanhai Li +4 位作者 Jiwen Ge Achal Varenyam Gabriel Habiyaremye Nzayisenga Theoneste Kamanzi Emmanuel 《Geoscience Frontiers》 SCIE CAS 2011年第4期599-607,共9页
This study has focused on the processes of soil degradation and chemical element concentration in tea-growing regions of Rwanda,Africa.Soil degradation accelerated by erosion is caused not only by topography but also ... This study has focused on the processes of soil degradation and chemical element concentration in tea-growing regions of Rwanda,Africa.Soil degradation accelerated by erosion is caused not only by topography but also by human activities.This soil degradation involves both the physical loss and reduction in the amount of topsoil associated with nutrient decline.Soil samples were collected from eleven tropical zones in Rwanda and from variable depth within each collecting site.Of these,Samples from three locations in each zone were analyzed in the laboratory,with the result that the pH of all soil samples is shown to be less than 5(pH〈5) with a general average of 4.4.The elements such as iron(Fe), copper(Cu),manganese(Mn),and zinc(Zn) are present in high concentration levels.In contrast calcium (Ca) and sodium(Na) are present at low-level concentrations and carbon(C) was found in minimal concentrations.In addition,elements derived from fertilizers,such as nitrogen(N),phosphorous(P),and potassium(K) which is also from minerals such as feldspar,are also present in low-level concentrations. The results indicate that the soil in certain Rwandan tea plantations is acidic and that this level of pH may help explain,in addition to natural factors,the deficiency of some elements such as Ca,Mg,P and N.The use of chemical fertilizers,land use system and the location of fields relative to household plots are also considered to help explain why tea plantation soils are typically degraded. 展开更多
关键词 Chemical elements Fertilizer use PH soil degradation Tea plantations
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Using Remote Sensing and GIS Techniques to Study Soil Degradation Processes in North Shaanxi Province,China 被引量:2
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作者 Mushtak Talib Jabbar 《Journal of China University of Geosciences》 SCIE CSCD 2003年第4期356-362,共7页
Satellite image data and thematic map data were used to provide comprehensive views of surface-bound conditions such as soil and vegetation degradation. The current work applies a computerized parametric methodology, ... Satellite image data and thematic map data were used to provide comprehensive views of surface-bound conditions such as soil and vegetation degradation. The current work applies a computerized parametric methodology, developed by FAO, UNEP and UNESCO to assess and evaluate soil degradation at 1∶250 000 mapping scale. The study area is located in the arid and semi-arid zone of the northern part of Shaanxi Province in China, a region with considerable agricultural potential; Landsat TM images were utilized to provide recent data on land cover and use of the area. ARC/INFO and ArcView softwares were used to manage and manipulate thematic data, to process satellite images, and tabular data source. ER mapper software is utilized to derive the normalized difference vegetation index (ND VI) values while field data to estimate soil erodibility ( SE ) factor. A system is established for rating soil parameters, slope, climate factor and human factor activity. The rating values serve as inputs into a modified universal soil loss equation (USLE) to calculate the present state and risk for soil degradation processes, namely soil wind erosion. The produced maps and tabular data show the risk and the present status of different soil degradation processes. The study area, in general, is exposed to high risk of wind erosion and high hazards of water erosion. Several desertification maps were produced, which reflect the desertification types persisting in the study area. Wind erosion, water erosion, vegetation degradation, physical degradation and salinization are the basic desertification maps, and others are combinations of these basic maps. In terms of statistic analysis, 33.75 % of the total land area (120.330 0 ha) is considered as sand or sand dune, and not included in our analysis of desertification. About 29.41 % of the total land area has slight or moderate desertification and 37.465 % is facing severe desertification. 展开更多
关键词 soil degradation DESERTIFICATION GIS remote sensing China.
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Institutions,policies and soil degradation:theoretical examinations and case studies in Southeast China
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作者 Nico Heerink 《Chinese Journal of Population,Resources and Environment》 2004年第2期20-27,共8页
Southeast China is one of the severe soil degradation areas in China. This paper theoretically examines the impact of some important institutional arrangements and policies, like land management pattern, the rural off... Southeast China is one of the severe soil degradation areas in China. This paper theoretically examines the impact of some important institutional arrangements and policies, like land management pattern, the rural off-farm employment, land property change and changes in prices of agricultural products, on soil degradation in this area. It further conducts some case studies to confirm the potential relationship between the institutions & policies and soil degradation, applying the surveyed and the second hand data. The paper at last makes some conclusions and proposes some suggestions on how to promote soil conservation by improving the ways of policy decision-making and the effects of policies on land use. 展开更多
关键词 Institutions POLICIES soil degradation Southeast China
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Remote sensing of soil degradation:Pro gress andperspective 被引量:1
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作者 Jingzhe Wang Jianing Zhen +4 位作者 Weifang Hu Songchao Chen Ivan Lizaga Mojtaba Zeraatpisheh Xiaodong Yang 《International Soil and Water Conservation Research》 SCIE CSCD 2023年第3期429-454,共26页
Soils constitute one of the most critical natural resources and maintaining their health is vital for agricultural development and ecological sustainability,providing many essential ecosystem services.Driven by climat... Soils constitute one of the most critical natural resources and maintaining their health is vital for agricultural development and ecological sustainability,providing many essential ecosystem services.Driven by climatic variations and anthropogenic activities,soil degradation has become a global issue that seriously threatens the ecological environment and food security.Remote sensing(RS)technologies have been widely used to investigate soil degradation as it is highly efficient,time-saving,and broad-scope.This review encompasses recent advances and the state-of-the-art of ground,proximal,and novel Rs techniques in soil degradation-related studies.We reviewed the RS-related indicators that could be used for monitoring soil degradation-related properties.The direct indicators(mineral composition,organic matter,surface roughness,and moisture content of soil)and indirect proxies(vegetation condition and land use/land cover change)for evaluating soil degradation were comprehensively summarized.The results suggest that these above indicators are effective for monitoring soil degradation,however,no indicators system has been established for soil degradation monitoring to date.We also discussed the RS's mechanisms,data,and methods for identifying specific soil degradation-related phenomena(e.g.,soil erosion,salinization,desertification,and contamination).We investigated the potential relations between soil degradation and Sustainable Development Goals(SDGs)and also discussed the challenges and prospective use of RS for assessing soil degradation.To further advance and optimize technology,analysis and retrieval methods,we identify critical future research needs and directions:(1)multi-scale analysis of soil degradation;(2)availability of RS data;(3)soil degradation process modelling and prediction;(4)shared soil degradation dataset;(5)decision support systems;and(6)rehabilitation of degraded soil resource and the contribution of RS technology.Because it is difficult to monitor or measure all soil properties in the large scale,remotely sensed characterization of soil properties related to soil degradation is particularly important.Although it is not a silver bullet,RS provides unique benefits for soil degradation-related studies from regional to global scales. 展开更多
关键词 soil degradation Remote sensing soil properties Earth observation Sustainable development goals
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Analysis and Assessment on the Heavy Metals in a Severely Degraded Subtropical Red Soil Region
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作者 Fang Wang Yun Zhou +5 位作者 Xiangping Fu Yuxiao Zhao Yiyao Wen Xintao Cui Shunbao Lu Yanjie Zhang 《American Journal of Plant Sciences》 CAS 2024年第2期110-121,共12页
5 different forests of Pinus massoniana, Schima superba, Liquidambar formosana, P. massoniana × S. superba, P. massoniana × L. formosana as the research object were set up to study the Cr, Cu and Zn content ... 5 different forests of Pinus massoniana, Schima superba, Liquidambar formosana, P. massoniana × S. superba, P. massoniana × L. formosana as the research object were set up to study the Cr, Cu and Zn content of degraded red soil region in subtropics. The soil heavy metal pollution degree was evaluated by national environmental quality standard (II class). The results showed that three soil metals of P. massoniana × S. superba were the highest, and the soil metals enrichment ability was strong. The order of single factor pollution index of metal elements was Cu (1.38) > Cr (0.81) > Zn (0.42), and moderately pollution, pollution warning and no pollution, respectively. There was no significant correlation between three soil heavy metals and soil total carbon (TC), total nitrogen (TN) and total phosphorus (TP). These results suggested that the accumulation of heavy metal elements was not derived from the parent material of soil. There was a significant positive correlation between the three metal elements which indicated that the sources of the three elements were similar. The structural equation model showed that the direct and indirect effects among the influencing factors ultimately affected the activity of heavy metals by cascade effects. 展开更多
关键词 Subtropical Forest Type Degraded Red soil Heavy Metals Pollution Evaluation
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Controllable Effect of Structural Modification of Sulfonylurea Herbicides on Soil Degradation 被引量:2
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作者 Xuewen Hua Shaa Zhou +7 位作者 Minggui Chen Wei Wei Ming Liu Kang Lei Sha Zhou Yonghong Li Baolei Wang Zhengming Li 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2016年第11期1135-1142,共8页
The study of soil degradation behaviors of sulfonylurea herbicides in relation to their different structural attributes is utmost important for us to comprehend the development of new eco-friendly herbicides. It is po... The study of soil degradation behaviors of sulfonylurea herbicides in relation to their different structural attributes is utmost important for us to comprehend the development of new eco-friendly herbicides. It is postulated that the structural modification of the chemical structures could influence their degradation rates in soil. Nine devised structures were synthesized to study their herbicidal activity as well as their soil degradation behaviors respectively. The novel compounds I-3-I-7 were characterized by UV, ^1H NMR and ^13C NMR, MS and EA. Bioassays indicated that most of target compounds displayed superior herbicidal activities in comparison with Chlorsulfuron. Soil degradation results further confirmed our previous assumption that the introduction of electron-donating substituents at 54 position of the benzene ring distinctly increased their degradation rates, among which dimethylamino and diethylamino groups can adjust the degradation rate to a more favorable status. 展开更多
关键词 sulfonylurea herbicides SYNTHESIS herbicidal activity soil degradation
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Research on controllable alkaline soil degradation of 5-substituted chlorsulfuron 被引量:2
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作者 Shaa Zhou Xuewen Hua +5 位作者 Wei Wei Minggui Chen Yucheng Gu Sha Zhou Haibin Song Zhengming Li 《Chinese Chemical Letters》 SCIE CAS CSCD 2018年第6期945-948,共4页
Sulfonylurea(SU) has become one class of the most important herbicides worldwide due to their ultralow application rate and mammalian toxicity. Recently application licenses of 3 classical SU herbicides chlorsulfuro... Sulfonylurea(SU) has become one class of the most important herbicides worldwide due to their ultralow application rate and mammalian toxicity. Recently application licenses of 3 classical SU herbicides chlorsulfuron, metsulfuron-methyl and ethametsulfuron were suspended due to their undesirable long persistence which is incompatible with the particular rotation planting system in China. Our previous study has discovered that electron-donating groups, especially dimethylamino and diethylamino substituents, on the 5 th position of the benzene ring in chlorsulfuron, greatly accelerated its degradation rate in an acidic soil(p H 5.41). Owing to the natural slower degradation of SUs in alkaline soil,dimethylamino and diethylamino substituted chlorsulfuron Ia and Ib were further studied in an alkaline soil(p H 8.46) with chlorsulfuron as a control. The experimental data indicated that the half-life of degradation(DT50) of Ia was 3.36 days while Ib was 6.25 days which amounted to 30 and 15 folds faster than chlorsulfuron(DT5084.53 days), respectively. The research confirmed that our newly-designed structures Ia and Ib can hasten their degradation rate in alkaline soil as well as in acidic soil. This structural modification of the classical SU provided an opportunity to control the degradation rate to reduce their impact on relevant environment and ecology. 展开更多
关键词 Chlorsulfuron Sulfonylurea herbicides soil degradation Alkaline soil DT50
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Short-term effects of post-fire mulching with straw or wood chips on soil properties of semi-arid forests 被引量:1
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作者 Manuel Esteban Lucas Borja Demetrio Antonio Zema 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第6期1777-1790,共14页
Few studies have compared the variability of soil properties using different types of mulches in semi-arid forests.This study evaluated the changes in physico-chemical soil properties in a semi-arid forest of Central ... Few studies have compared the variability of soil properties using different types of mulches in semi-arid forests.This study evaluated the changes in physico-chemical soil properties in a semi-arid forest of Central Eastern Spain,where straw and pine wood chips were distributed as mulch three months after a wildfire.Soils were sampled under burned and unmulched and burned and mulched plots three and nine months after the treatments.The data was processed using Principal Component Analysis(PCA)and Analytical Hierarchical Cluster Analysis(AHCA).Mulching with straw or wood chips did not have any significant effects on the texture and chemical properties of burned sites few months after the treatment.In contrast,significant changes are expected over time in organic matter,nutrients and many ions.There were no significant differences in soil properties between the two mulches.These low changes were confirmed by PCA coupled with AHCA,which did not show a clear distinction among the three soil conditions.However,a noticeable and significant variability of many of these properties over time was evident.This study shows that mulching does not degrade of soil properties in the short-term after a wildfire and after post-fire treatments,and thus helps protect semi-arid forest ecosystems against the negative impacts of high-severity fires. 展开更多
关键词 Post-fire management High-severity fire ARIDISOLS Erosion Vegetal residues incorporation soil degradation
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Rangeland Degradation Impacts on Vegetation Cover, Soil Properties and Ecosystem Functioning in an Arid and Semi-Arid Climate, South Africa
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作者 Hermias Cornelius van der Westhuizen Christiaan Cornelius du Preez Hendrik Andries Snyman 《Journal of Geoscience and Environment Protection》 2022年第2期10-32,共23页
The negative effect of soil erosion and soil compaction is well documented for the purpose of optimum rangeland functioning, while the impact of rangeland degradation on effective soil depth is seldom quantified. The ... The negative effect of soil erosion and soil compaction is well documented for the purpose of optimum rangeland functioning, while the impact of rangeland degradation on effective soil depth is seldom quantified. The aim of this study was to quantify the response of vegetation cover and soil properties, particularly effective soil depth and soil texture to rangeland degradation. Forty-one farms were sampled in the arid and semi-arid climate of South Africa. Within these farms, data was collected over a vegetation degradation gradient. Results showed a significant decline in relative basal cover (94% ± 15% to 39% ± 17%) and soil depth (90% ± 14% to 73% ± 24%) as rangeland degraded. Soil texture changes over the degradation gradients vary for different homogeneous vegetation types. Indications regarding the loss of a functioning rangeland ecosystem were also demonstrated, using objective long-term relations between rangeland conditions and grazing capacity. The study highlights the importance of sustainable rangeland management practices to reduce the loss in effective soil depth and to ensure the sustainable utilization of the rangeland ecosystem. These results can probably extrapolate to other arid and semi-arid rangelands worldwide. 展开更多
关键词 Rangeland Condition soil degradation Effective soil Depth soil Erosion soil Compaction Ecosystem Functioning
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Agriculture and Soil Management in the Context of Sustainable Development in the Sudano-Sahelian Zone of Cameroon
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作者 Sidsi Bienvenu Vounba Claudine +1 位作者 Bahouro Arka Kolaouna Bruno Labara 《Journal of Geoscience and Environment Protection》 2023年第11期171-191,共21页
The Sudanian-Sahelian zone of the Far-North Cameroon faces an extreme climate challenge resulting in increased vulnerability to erosion, soil degradation, and the effects of climate change, impacting soil fertility an... The Sudanian-Sahelian zone of the Far-North Cameroon faces an extreme climate challenge resulting in increased vulnerability to erosion, soil degradation, and the effects of climate change, impacting soil fertility and agricultural yields. The objective of this study was to analyze agricultural practices, challenges related to climate change and soil degradation, as well as the solutions adopted by farmers to address these issues. To achieve this, 600 farmers from the six departments of the region were interviewed. The results highlight the significant impact of climatic conditions on soil health, agricultural activities, and food security. Farmers identified various indicators of soil degradation, including agricultural yields, bioindicator plants, plant growth, soil fauna, and root density. The main causes of soil degradation are associated with practices such as deforestation, intensive agriculture, the use of chemical fertilizers and pesticides, overgrazing, and the effects of climate change. The impacts of this degradation are multiple, including soil fertility loss, reduced agricultural yields, deforestation, reduced biodiversity, income loss, water resource pollution, and food insecurity. In response to these challenges, farmers have adopted sustainable soil management practices, including crop rotation, intercropping, fallowing, the use of organic fertilizers, and the adoption of conservation agriculture. To effectively address these challenges, concerted collaboration between farmers, civil society organizations, and government authorities is imperative to develop sustainable and effective solutions against soil degradation in the region. 展开更多
关键词 AGRICULTURE soil degradation Climate Change Food Security Sudanian-Sahelian Zone Cameroon
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Lindane Degradation and Effects on Soil Microbial Activity
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作者 M. FARGHALY S. M. A. D. ZAYED +2 位作者 F. MAHDY AND SOLIMAN M. SOLIMAN (National Research Centre, Dekki, Chiro, Egypt Middle EasternRegional Radioisotopes Centre for the Arab Countries , Dokki, Chiro, Egypt) 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1998年第3期218-225,共8页
The degradation of U-14C-lindane in two Egyptian soils was determined in a three-month laboratory incubation. Lindane mineralization was slow and limited in both soils. Evolution of 14CO2 increased with time but only ... The degradation of U-14C-lindane in two Egyptian soils was determined in a three-month laboratory incubation. Lindane mineralization was slow and limited in both soils. Evolution of 14CO2 increased with time but only reached 3. 5 to 5. 5 % of the initial 14C-concentration within 90 days. At that time both soils contained about 88 % of the applied radiocarbon; 33 % to 37% of the initial dose was unextractable and assumed bound to the soils. The methanol-ex-tractable 14C primarily contained lindane with traces of minor metabolites. Radiorespirometry was used to eva1uate the effect of lindane on soil microbial activity. Low concentrations of the insecticide initially supressed 14CO2 evolution from U-14C-glucose and microbial activity was significantly inhibited by 10 mg lindane/kg soil. 展开更多
关键词 CO USA Lindane degradation and Effects on soil Microbial Activity
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Impact of land cover types on the soil characteristics in karst area of Chongqing 被引量:6
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作者 LI Yangbing XIE Deti WANG Shijie 《Journal of Geographical Sciences》 SCIE CSCD 2006年第2期143-154,共12页
The 26 plots including natural forestland, secondary forestland, shrub-grassland, sloping cropland, artificial forest and abandoned field, were selected to discuss the impact of land cover on the soil characteristics ... The 26 plots including natural forestland, secondary forestland, shrub-grassland, sloping cropland, artificial forest and abandoned field, were selected to discuss the impact of land cover on the soil characteristics in the three karst districts of Chongqing. The results showed that: (1) After the vegetation turned into secondary vegetation or artificial vegetation, or reclamation, soil physical properties would be degraded. In the surface-layer soil of sloping cropland, the contents of 〉2 mm water-stable aggregates decreased obviously with apparent sandification. (2) The contents of soil organic matter and total nitrogen are controlled completely by vegetation type and land use intensity. The increasing trend is rather slow in the early days when over-reclamation is stopped and the land is converted to forest and pasture. (3) Herbaceous species increase and woody plants species decrease with the increase of land use intensity, therefore, the soil seed banks degrade more seriously. (4) The soil degradation index has been set up to describe the relative soil degradation degree under the conditions of different vegetation types. (5) Land cover has a significant effect on karst soil characteristics, land degradation in the karst ecosystem is essentially characterized by the different degradation of soil functions that serve as water banks, nutrient banks and soil seed banks. 展开更多
关键词 karst ecosystem vegetation evolution soil degradation soil seed bank soil-land ecology CHONGQING
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Land cover changes and the effects of cultivation on soil properties in Shelihu wetland,Horqin Sandy Land,Northern China 被引量:4
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作者 Jie LIANI XueYong ZHAO +3 位作者 XiaoAn ZUO ShaoKun WANG XinYuan WANG YongQing LUO 《Journal of Arid Land》 SCIE CSCD 2013年第1期71-79,共9页
Land cover change plays an essential role in the alternation of soils properties. By field investigation and applying satellite images, land cover information in the Shelihu wetland was carried out in an area of 2,819... Land cover change plays an essential role in the alternation of soils properties. By field investigation and applying satellite images, land cover information in the Shelihu wetland was carried out in an area of 2,819 hm2 in 1985, 1995, 2000, 2005, 2010 and 2011, respectively, in Horqin Sandy Land. A total of 57 soil sampling sites across Shelihu were chosen in wet meadow (CL0), cropland (CL) and sandy land (SL) according to the spatial characteristics of water body change. Soil texture, organic carbon (SOC), total nitrogen (TN) and total phosphorus (TP) contents, electrical conductivity (EC) and pH were measured at the soil depths of 0-10, 10-20 and 20-40 cm to examine the influence of agricultural conversion and continuous cultivation on soil properties. The results showed that the study area was covered by water body in 1985, which gradually declined afterwards and then reclaimed rapidly at a mean annual rate of 132.1 hm2/a from wet meadow to cropland since 1995. In 2011, water body was drained and the area was occupied by 10.8% of CL0, 76.9% of CL and 12.3% of SL. Large amounts of SOC, TN and TP were accumulated in the above depths in CL0. Soil in CL0 also had higher EC and silt and clay fractions, lower pH than in SL and CL. Soil in SL was seriously degraded with lower contents of SOC, TN and TP than in CL and CL0. SOC, TN content and EC in CL decreased with the increase of cultivation age, while pH showed a reverse trend with significance at plough horizon. The agricultural conversion in Shelihu was driven by the comprehensive factors of precipitation reduction, economic development and intense competitions for irrigation water. Continuous cultivation in this process is not sustainable because of SOC degradation and nutrient content reduction. The key point is that conventional tillage and removal of residuals induced further land degradation. Wetland reclamation for immediate economic interests led to greater costs in the long-term environmental restoration in Horqin Sandy Land. 展开更多
关键词 WETLAND soil degradation wetland reclamation continuous cultivation Horqin Sandy Land
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Study on soils under shifting cultivation and other land use categories in Chittagong Hill Tracts, Bangladesh 被引量:3
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作者 Alake Biswas M.Alamgir +1 位作者 S.M.S.Haque K.T.Osman 《Journal of Forestry Research》 CAS CSCD 2012年第2期261-265,共5页
Soil samples were collected and analyzed from 25 sites of three hilly regions (Rangamati, Banderban and Khagrachari) for an understanding of the impact of denudation and land use on soils in Chittagong Hill Tracts, ... Soil samples were collected and analyzed from 25 sites of three hilly regions (Rangamati, Banderban and Khagrachari) for an understanding of the impact of denudation and land use on soils in Chittagong Hill Tracts, Bangladesh. There were natural forests, bushy land, slashed sites, slashed and burnt sites, and the sites prepared for shifting cultivation, one year after shifting cultivation and two years after shifting cultivation. The soils were generally yellowish brown to reddish brown, sandy to sandy clay loam, strongly acid, and well to excessively drained on steep slopes with considerable variation among the sites and land use categories. Bulk density was the highest in sites of one year after shifting cultivation (1.52 g·cm^-3) and the lowest in forested sites (1.38 g·cm^-3). Water holding capacities were, however, statistically similar in all sites. Organic carbon varied from 0.54% (slashed and burnt sites) to 1.55% (forested sites) and total N ranged from 0.05% (shifting cultivation for one year) to 0.13% (forested sites). Available phosphorus (Bray & Kurtz-2 P) was the maximum in forested sites (12.32 mg·kg^-l), and it did not differ significantly in other sites. Contents of available Ca, Mg and K were also higher in the bushy lands and forested sites than cleared and shifting cultivated sites. 展开更多
关键词 Chittagong Hill Tracts BANGLADESH DENUDATION shifting cultivation soil degradation
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Influences of Seasonal Freezing and Thawing on Soil Water-stable Aggregates in Orchard in High Cold Region,Northeast China 被引量:3
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作者 LIANG Yunjiang DENG Xu +4 位作者 SONG Tao CHEN Guoshuang WANG Yuemei ZHANG Qing LU Xinrui 《Chinese Geographical Science》 SCIE CSCD 2021年第2期234-247,共14页
Soil aggregate stability,as an important indicator of soil functions,may be affected by seasonal freezing and thawing(SFT)and land use in high cold and wet regions.Therefore,comprehensive understanding the effects of ... Soil aggregate stability,as an important indicator of soil functions,may be affected by seasonal freezing and thawing(SFT)and land use in high cold and wet regions.Therefore,comprehensive understanding the effects of SFT on aggregate stability in orchards during winter and spring is crucial to develop appropriate management strategies that can effectively alleviate the degradation of soil quality to ensure sustainable development of orchard ecosystems.To determine the mechanism of degradation in orchard soil quality,the effects of SFT on the stability of water-stable aggregates were examined in apple-pear orchards(Pyrus ussuriensis var.ovoidea)of four different ages(11,25,40,and 63 yr)on 0 to 5%slopes before freezing and after thawing from October 2015 to June 2016 in Longjing City,Yanbian Prefecture,Northeast China,involving a comparison of planted versus adjacent uncultivated lands(control).Soil samples were collected to investigate water-stable aggregate stability in three incremental soil layers(0–20,20–40 and 40–60 cm).In the same samples,iron oxide,organic matter,and clay contents of the soil were also determined.Results showed that the destructive influences of SFT on water-stable aggregates were more pronounced with the increased orchards ages,and SFT exerted severe effects on water-stable aggregates of older orchards(40 and 63 yr)than juvenile orchards.Undergoing SFT,the soil instability index and the percentage of aggregate destruction increased by mean 0.15 mm and 1.86%,the degree of aggregation decreased by mean 1.32%,and the erosion resistance weakened,which consequently led to aggregate stability decreased.In addition,soil free,amorphous,and crystalline iron oxide as well as soil organic matter and clay contents are all important factors affecting the stability of water-stable aggregates,and their changes in their contents were consistent with those in the stability of water-stable aggregates.The results of this study suggest that long-term planting fruit trees can exacerbate the damaging effects of SFT on aggregate stability and further soil erosion increases and nutrient losses in an orchard,which hider sustainable use of soil and the productivity orchards. 展开更多
关键词 water-stable aggregates orchard age apple-pear orchard soil seasonal freezing and thawing soil degradation high cold region
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Residue analysis and dissipation of monosulfuron in soil and wheat 被引量:1
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作者 FANZhi-jin HUJi-ye +3 位作者 AIYing-wei QIANChuan-fan YUWei-qiang LIZheng-ming 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2004年第5期717-721,共5页
HPLC-UV residue analytical method for monosulfuron [N-[( 4' -methyl) pyrimidin- 2' -yl]-2-nitrophenylsulfonyl urea] in soil and wheat was developed. Monosulfuron residues were recovered by solvent extract... HPLC-UV residue analytical method for monosulfuron [N-[( 4' -methyl) pyrimidin- 2' -yl]-2-nitrophenylsulfonyl urea] in soil and wheat was developed. Monosulfuron residues were recovered by solvent extraction, followed by liquid-liquid partition, and C 18 cartrige clean-up. Excellent method recoveries ranging from 95%—104% for both fortified soil and wheat grain were obtained with coefficients of variation 1.5%—11.8%. The minimum detectable quantities in soil and wheat were both 4 ng, the limit of detection was 0.02 mg/kg. When monosulfuron was applied according to double dosage of maximum recommended use direction(120 g ai/hm 2 of 10% monosulfuron wettable powder sprayed for once during development of wheat) in field studies conducted in Shandong Province and near Beijing, monosulfuron residues was not detected in soil and wheat samples collected 75 d after application. Laboratory soil degradation studies showed that monosulfuron degraded faster in acidic soil and strong alkaline soil than in neutral or weak alkaline soil. Half lives in Jiangxi soil, Shijiazhuang soil, Jiangsu soil and Heilongjiang soil were 41, 48, 87 and 84 d respectively. Monosulfuron residues dissipated rapidly in Shandong and Beijing field test sites with half-lives of less than 14 d. 展开更多
关键词 MONOSULFURON wheat (Triticum aestivum L.) soil degradation residue analysis
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Variation of Physical and Chemical Properties of Soils under Different Cropping Systems in the Watershed of Kpocomey, Southern Benin 被引量:1
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作者 Alladassi Félix Kouelo Alohoutade Finagnon Mathieu +7 位作者 Avakoudjo Julien Akplo Tobi Moriaque Agodo Lambert Agonvinon Mahugnon Socrate Houngnandan Pascal Azontonde Hessou Anastase Amadji Guillaume Lucien Saïdou Aliou 《Open Journal of Soil Science》 2020年第11期501-517,共17页
Soils degradation is one of the constraints in food security achievement in Benin. This study aimed at assessing the effect of cropping systems and slope on soil physical and chemical properties in the watershed of Kp... Soils degradation is one of the constraints in food security achievement in Benin. This study aimed at assessing the effect of cropping systems and slope on soil physical and chemical properties in the watershed of Kpacomey located in the Aplahoué district. Soil samples were collected from three parallel transects along the slope. Sampling was carried out under different treatments combining cropping systems (Maize-Cassava, pure Palm grove, Palm grove-Maize-Cassava and Teak Plantation) along with slope levels (low slope, medium slope and high slope degree). The impact of cropping systems and slope on soil properties was assessed by determining the physical and chemical parameters. The cropping systems significantly (p < 0.05) influenced soil bulk density, root biomass, soil acidity and soil organic matter. The lowest soil bulk density (1.38 g/cm<sup>3</sup>) was recorded under the Palm grove-Maize-Cassava cropping system while the highest (1.47 g/cm<sup>3</sup>) was obtained with pure Palm grove cropping system. Root biomass was more abundant (0.28%) with the pure Palm grove cropping system. However, root biomass was significantly (p < 0.05) influenced by slope. Soil crusting resulted in no significant influence (p > 0.05) on the effect of cropping systems and slope. Moreover, cropping systems resulted in significant effects (p < 0.05). Soil organic matter and soil-assimilated phosphorus content were significantly influenced by the effect of the slope. These findings indicated that cropping systems and slope are significant drivers in soil degradation in the Kpacomey watershed and bringing out cropping systems that best aim at soil conservation. 展开更多
关键词 Cropping Systems soil Organic Matter soil degradation BENIN
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Functions of Russian Melilotus officinalis on Degraded Soil Improvement 被引量:1
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作者 Shuo LIANG Nianfeng LIN +1 位作者 Jie TANG Yuefen LI 《Agricultural Biotechnology》 CAS 2018年第5期208-211,共4页
To improve the serious situation of soil degradation in China, tests were carried out to study the improvement effects of Russian Melilotus officinalis on the low base saturation acid soil, the alkaline-saline soil an... To improve the serious situation of soil degradation in China, tests were carried out to study the improvement effects of Russian Melilotus officinalis on the low base saturation acid soil, the alkaline-saline soil and the heavy metal contaminated soil. The results showed that M. officinalis could improve the low base saturation acid soil, increase the salt, alkali content, mineral nutrition and organic nutrient, which indicated that M. officinalis could be planted in the acid soil, and had a significant ecological effect on soil improvement. M. officinalis achieved a remarkable effect on improving the alkaline-saline soil (pH 8.5-9.5) that the soil desalted, dealkalized and had more organic nutrient. Moreover, M. officinalis could improve the heavy metal contaminated soil and had the ability to enrich and transform heavy metal elements, especially Cd and Ni, thereby presenting significant repair effects on soil improvement. Therefore, Russian M. officinalis had multiple-effects on degraded soil improvement, so it is worthy of application and popularization. 展开更多
关键词 Russian Melilotus officinalis soil degradation soil improvement test FUNCTIONS
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Lithic soils in the semi-arid region of Brazil:edaphic characterization and susceptibility to erosion
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作者 Carlos R PINHEIRO JUNIOR Conan A SALVADOR +6 位作者 Tiago R TAVARES Marcel C ABREU Hugo S FAGUNDES Wilk S ALMEIDA Eduardo C SILVA NETO Lúcia H C ANJOS Marcos G PEREIRA 《Journal of Arid Land》 SCIE CSCD 2022年第1期56-69,共14页
Soils(Leptosols or Epileptic Regosols)with lithic contact at a depth of 50 cm occupy almost 20%of the Brazilian semi-arid region.These lithic soils are susceptible to erosion due to faster saturation of water-holding ... Soils(Leptosols or Epileptic Regosols)with lithic contact at a depth of 50 cm occupy almost 20%of the Brazilian semi-arid region.These lithic soils are susceptible to erosion due to faster saturation of water-holding capacity during rainfall,which accelerates the beginning of runoff.However,erosion traits of lithic soils in the semi-arid region of Brazil are less studied.The aim of this study was to characterize the soil and landscape attributes in areas with Neossolos Litólicos(Entisols)in the Caatinga biome to identify region of high susceptibility to erosion.Results showed that the soils were characterized by a sandy texture,soil structure with poor development and low content of organic carbon.These attributes increase susceptibility to erosion and reduce water storage capacity,especially in the states of Cearáand Sergipe.In these states,the content of rock fragments in the soil reaches 790 g/kg.High contents of silt and fine sand,high silt/clay ratio,predominance of Leptosols and strong rainfall erosivity were observed in Piauíand northwestern Ceará.A very high degree of water erosion was observed in the states of Pernambuco and Paraíba.Despite the low degree of erosion observed in the state of Bahia,it is highly susceptible to erosion due to the predominance of very shallow soils,rugged relief and high values of rainfall erosivity.Lower vulnerability was observed in the state of Alagoas because of its more smoothed relief,greater effective soil depth,thicker A horizon of soil and lower rainfall erosivity.In general,the characteristics that intensify the susceptibility to erosion in the Caatinga biome are those soil structures with poor development or without aggregation,low contents of organic carbon,high contents of silt and fine sand,high values of silt/clay ratio and rugged relief in some regions.This study collected information contributing to a better characterization of soils with lithic contact in the semi-arid region of Brazil.In addition,regions with a higher susceptibility to erosion were identified,revealing insights that could help develop strategies for environmental risk mitigation. 展开更多
关键词 Caatinga biome DRYLANDS erosive processes leptosols soil degradation
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