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Soil Cover in the Eastern Part of the Dried Bed of the Aral Sea
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作者 Galina Stulina Kamaladin Idirisov 《Journal of Geoscience and Environment Protection》 2024年第6期30-37,共8页
The greatest environmental disaster in Central Asiathe drying up of the Aral Seahas led to the formation of a new terrain, extending over 2.7 million hectares in Uzbekistan. This newly formed terrain is dynamically de... The greatest environmental disaster in Central Asiathe drying up of the Aral Seahas led to the formation of a new terrain, extending over 2.7 million hectares in Uzbekistan. This newly formed terrain is dynamically developing, with emerging soil formations replacing bottom sediments. This paper analyzes the results of a study on soil formation in the eastern part of the dried-up seabed, focusing on the influence of natural processes occurring there. 展开更多
关键词 Aral Sea Environmental Dried Seabed soil cover
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Optimization of mechanized soil covering path based on the agronomic mode of full-film double-ditch with double-width filming 被引量:2
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作者 Fei Dai Wenjuan Guo +4 位作者 Xuefeng Song Yang Zhang Ruijie Shi Feng Wang Wuyun Zhao 《International Journal of Agricultural and Biological Engineering》 SCIE CAS 2022年第1期139-146,共8页
In order to further improve the working performance and efficiency of mechanized tillage operation of a full-film double-ditch seedbed,under the working conditions of different parameters of the spiral push-type soil ... In order to further improve the working performance and efficiency of mechanized tillage operation of a full-film double-ditch seedbed,under the working conditions of different parameters of the spiral push-type soil covering device with double-width filming,the dynamic soil covering characteristics and soil covering uniformity of the device were analyzed,the collaborative and interactive coupling mechanism of the horizontal pushing process of the mulching soil and horizontally two-way spiral soil transmission device were revealed,and the main reasons for the influence of different soil covering belts on the change of soil particle number distribution were analyzed.Based on the full-film double-ditch mode with double-width filming,the mechanized soil covering path was optimized.In order to further reduce the disturbance on mulching soil by two-way spiral pushing,a kind of parallel shunt type soil covering device with double-width filming was designed,then a discrete element method was adopted to make simulation analysis and optimize the parallel shunt type soil covering device with double-width filming.Field verification tests showed that after the operation of the full-film double-ditch combined machine with double-width filming and soil covering installed with the parallel shunt type soil covering device,the qualified rate of the film edge soil covering width was 96.1%,an increase of 1.6%compared to that before optimization;the qualified rate of soil covering width at the center of the big ridge was 93.5%,an increase of 1.9%compared to that before optimization;the qualified rate of the soil covering thickness was 97.7%,an increase of 0.2%compared to that before optimization.The test indicators reached the requirements of relevant national and industrial standards,showing that the test results met the design requirements,and the working conditions of verification tests were consistent with the simulation results. 展开更多
关键词 full-film double-ditch double-width filming soil covering soil covering path optimization soil covering device
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Soil seed bank is affected by transferred soil thickness and properties in the reclaimed coal mine in the Qilian Mountains, China
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作者 YANG Jingyi LUO Weicheng +3 位作者 ZHAO Wenzhi LIU Jiliang WANG Dejin LI Guang 《Journal of Arid Land》 SCIE CSCD 2023年第12期1529-1543,共15页
Reclamation of lands abandoned after mining in mountain areas is critical to erosion control,safety from landslides,and ecological protection of mountain ecosystems.However,little is known about alpine coal mine recla... Reclamation of lands abandoned after mining in mountain areas is critical to erosion control,safety from landslides,and ecological protection of mountain ecosystems.However,little is known about alpine coal mine reclamation using the soil seed bank as a potential source for revegetation.We collected samples of persistent soil seed bank for germination experiments from nine reclaimed sites with different soil cover thicknesses and from six control sites in the Qilian Mountains of China.Soil properties of each site were determined(including soil water content,soil available potassium,soil available phosphorus,soil total nitrogen,pH,soil organic matter,soil total phosphorus,and soil total potassium,and soil alkali-hydrolyzable nitrogen),and the relationships of the characteristics of the soil seed bank with soil cover thickness and soil properties were examined.The results showed that the density,number of species,and diversity of the topsoil seed bank were significantly correlated with soil cover thickness,and all increased with the increment of soil cover thickness.Soil cover thickness controlled the soil seed bank by influencing soil properties.With the increase in soil cover thickness,soil properties(e.g.,soil organic matter,soil total nitrogen,etc.)content increased while soil pH decreased.The soil seed bank had the potential to restored the pre-mining habitat at reclaimed sites with approximately 20-cm soil cover thickness.Soil properties of reclaimed sites were lower than that of natural sites.The relationship between the soil seed bank and soil cover thickness determined in this study provides a foundation for improving reclamation measures used in coal mines,as well as for the management and monitoring of reclaimed areas. 展开更多
关键词 soil seed bank soil cover thickness species composition soil properties Qilian Mountains
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Minimizing N2O fluxes from full-scale municipal solid waste landfill with properly selected cover soil 被引量:3
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作者 ZHANG Houhu HE Pinjing +2 位作者 SHAO Liming QU Xian LEE Duujong 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第2期189-194,共6页
Municipal solid waste landfills emit nitrous oxide (N2O) gas. Assuming that the soil cover is the primary N2O source from landfills, this study tested, during a four-year project, the hypothesis that the proper use ... Municipal solid waste landfills emit nitrous oxide (N2O) gas. Assuming that the soil cover is the primary N2O source from landfills, this study tested, during a four-year project, the hypothesis that the proper use of chosen soils with fine texture minimizes N2O emissions. A full-scale sanitary landfill, a full-scale bioreactor landfill and a cell planted with Nerium indicum or Festuca arundinacea Schreb, at the Hangzhou Tianziling landfill in Hangzhou City were the test sites. The N2O emission rates from all test sites were considerably lower than those reported in the published reports. Specifically, the N2O emission rate was dependent on soil water content and nitrate concentrations in the cover soil. The effects of leachate recirculation and irrigation were minimal. Properly chosen cover soils applied to the landfills reduced N2O flux. 展开更多
关键词 municipal solid waste landfill N2O flux cover soil LEACHATE NITRIFICATION/DENITRIFICATION environmental factors
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Accurate Quantification of Grassland Cover Density in an Alpine Meadow Soil Based on Remote Sensing and GPS 被引量:12
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作者 LIU Yan-Sui HU Ye-Cui PENG Liu-Ying 《Pedosphere》 SCIE CAS CSCD 2005年第6期778-783,共6页
The principles of remotely estimating grassland cover density in an alpine meadow soil from space lie in the synchronous collection of in situ samples with the satellite pass and statistically linking these cover dens... The principles of remotely estimating grassland cover density in an alpine meadow soil from space lie in the synchronous collection of in situ samples with the satellite pass and statistically linking these cover densities to their image properties according to their geographic coordinates. The principles and procedures for quantifying grassland cover density from satellite image data were presented with an example from Qinghai Lake, China demonstrating how quantification could be made more accurate through the integrated use of remote sensing and global positioning systems (GPS). An empirical model was applied to an entire satellite image to convert pixel values into ground cover density. Satellite data based on 68 field samples was used to produce a map of ten cover densities. After calibration a strong linear regression relationship (r2 = 0.745) between pixel values on the satellite image and in situ measured grassland cover density was established with an 89% accuracy level. However, to minimize positional uncertainty of field samples, integrated use of hyperspatial satellite data and GPS could be utilized. This integration could reduce disparity in ground and space sampling intervals, and improve future quantification accuracy even more. 展开更多
关键词 青海湖 草地 遥感技术 覆盖密度 高山
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Effects of Land Cover on Soil Organic Carbon Stock in a Karst Landscape with Discontinuous Soil Distribution 被引量:14
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作者 CHEN Xiang-bi ZHENG Hua +5 位作者 ZHANG Wei HE Xun-yang LI Lei WU Jin-shui HUANG Dao-you SU Yi-rong 《Journal of Mountain Science》 SCIE CSCD 2014年第3期774-781,共8页
Land cover type is critical for soil organic carbon(SOC) stocks in territorial ecosystems. However, impacts of land cover on SOC stocks in a karst landscape are not fully understood due to discontinuous soil distribut... Land cover type is critical for soil organic carbon(SOC) stocks in territorial ecosystems. However, impacts of land cover on SOC stocks in a karst landscape are not fully understood due to discontinuous soil distribution. In this study, considering soil distribution, SOC content and density were investigated along positive successional stages(cropland, plantation, grassland, scrubland, secondary forest, and primary forest) to determine the effects of land cover type on SOC stocks in a subtropical karst area. The proportion of continuous soil on the ground surface under different land cover types ranged between 0.0% and 79.8%. As land cover types changed across the positive successional stages, SOC content in both the 0–20 cm and 20–50 cm soil layers increased significantly. SOC density(SOCD) within 0–100 cm soil depth ranged from 1.45 to 8.72 kg m-2, and increased from secondary forest to primary forest, plantation, grassland, scrubland, and cropland, due to discontinuous soil distribution. Discontinuous soil distribution had a negative effect on SOC stocks, highlighting the necessity for accurate determination of soil distribution in karst areas. Generally, ecological restoration had positive impacts on SOC accumulation in karst areas, but this is a slow process. In the short term, the conversion of croplandto grassland was found to be the most efficient way for SOC sequestration. 展开更多
关键词 土壤有机碳库 土地覆盖类型 喀斯特景观 连续分布 土壤有机碳密度 喀斯特地区 有机碳含量 土壤分布
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SPATIAL-TEMPORAL VARIATION OF HEAVY METAL ELEMENTS CONTENT IN COVERING SOIL OF RECLAMATION AREA IN FUSHUN COAL MINE 被引量:5
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作者 YUJun-bao LIUJing-shuang 《Chinese Geographical Science》 SCIE CSCD 2002年第3期268-272,共5页
Grid method is employed for sampling covering soil at the test field,whic h is reclamation area filled by coal mining wastes for cropland in th e Fushun coal mine,Liaoning Province,the Northeast China.The soil samp le... Grid method is employed for sampling covering soil at the test field,whic h is reclamation area filled by coal mining wastes for cropland in th e Fushun coal mine,Liaoning Province,the Northeast China.The soil samp les are taken at different locations,inclu ding three kinds of covering soil,th ree different depths of soil layers a nd four different covering ages of covering soil.The s patial-temporal variation of heavy metal element content in reclamatio n soil is stud-ied.The results indicate that the co ntent of heavy metal elements is decreasing year after year;the determin ant reason why the content of heavy metal elemen ts at 60cm depth layer is higher than t hat at 30cm depth layer and surface is fertiliz-er and manure application;the metal elements mainly come from external environment;there is no metal pollut ion coming from mother material(coal mining wastes)in plough layer of covering soil. 展开更多
关键词 土壤 重金属元素 时空分布 复垦 抚顺煤矿
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Comparison of soil physico-chemical properties under different land-use and cover types in northeastern China's Horqin Sandy Land 被引量:4
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作者 YuQiang Li JianPeng Zhang +4 位作者 XueYong Zhao TongHui Zhang YuLin Li XinPing Liu YinPing Chen 《Research in Cold and Arid Regions》 CSCD 2016年第6期495-506,共12页
The Horqin Sandy Land of northeastern China was originally a grassland with plenty of water and lush vegetation dominated by palatable grass species along with sparsely scattered woody species. However, it has experie... The Horqin Sandy Land of northeastern China was originally a grassland with plenty of water and lush vegetation dominated by palatable grass species along with sparsely scattered woody species. However, it has experienced severe desertification in recent decades due to its fragile ecology together with inappropriate human activities. Currently, the landscape of the Horqin Sandy Land is dominated by irrigated croplands and sand dunes with different degrees of vegetation cover, as the region has become the most important part of the semiarid agro-pastoral ecotone of northern China. In this study, we compared soil physical and chemical properties under different land-use and cover types (irrigated cropland, rainfed cropland, sandy grassland, fixed dunes, and mobile dunes). We found that soil particle size distribution; organic C, total N, and total mineral element, microelement, and available microelement and nutrient contents; pH; CEC; and bulk density differed significantly among the land-use and cover types. In general, soil quality was highest in the cropland, intermediate in the sandy grassland, and lowest in the dunes. The most important soil quality attribute, soil organic carbon (SOC) storage, decreased in the fol-lowing order: irrigated cropland (5,699 g/m^2) 〉 sandy grassland (3,390 g/m^2) 〉 rainfed cropland (2,411 g/m^2) 〉 fixed dunes (821 g/m^2) 〉 mobile dunes (463 g/m^2). SOC was significantly positively correlated with a large proportion of the other soil physico-chemical parameters. Our results suggest that the key issue in restoration of the degraded soils will be to increase SOC storage, which would also create a high potential for sequestering soil C in desertified areas of the Horqin Sandy Land. 展开更多
关键词 land use land cover soil properties DESERTIFICATION Horqin Sandy Land
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Species-diversified plant cover enhances orchard ecosystem resistance to climatic stress and soil erosion in subtropical hillsid 被引量:9
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作者 陈欣 杨一松 唐建军 《Journal of Zhejiang University Science》 EI CSCD 2004年第10期1191-1198,共8页
Naturally occurring plants in agroecosystem evidently play an important role in ecosystem stability. Field studies on the ecological effects of native plants conserved in orchard and their resistance to adverse climat... Naturally occurring plants in agroecosystem evidently play an important role in ecosystem stability. Field studies on the ecological effects of native plants conserved in orchard and their resistance to adverse climatic stress, and soil erosion were conducted from 1998 to 2001 in a newly developed Changshan-huyou (Citrus changshan-huyou Y.B. Chang) orchard. The experimental area covered 150 ha in typical red soil hilly region in southeastern China. The experimental design was a randomized complete block with six combinations of twelve plant species with four replications. All species used were native in the orchard. Plots were 15×8m^2 and separated by 2m buffer strips. Precipitation, soil erosion in rainstorm days and aboveground biomass of plant community when rainstorm days ended, soil temperature and moisture under various plant covers during seasonal megathermal drought period, antiscourability of soil with different root density under various simulated rainfalls were measured. Plant cover significantly decreased the daily highest and mean soil temperature and its daily variation in hot-drought season, but there was no significant difference of the alleviation among various plant covers. Plant covers significantly increased the soil moisture in seasonal megathermal drought period. Better moisture maintenance and soil erosion reduction was found when the plant species numbers in cover plant communities increased from one to eight. Higher root density in plant communities with higher species richness increased significantly the antiscourability of the soil. It was suggested that conserving plant communities with diversified native species could produce the best positive ecological effects on citrus orchard ecosystem stability. 展开更多
关键词 植物多样性 生态系统 气候 土壤侵蚀 生物多样性保护 生态平衡
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Prediction of spatial soil loss impacted by long-term land-use/land-cover change in a tropical watershed 被引量:2
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作者 J.H.Abdulkareem B.Pradhan +1 位作者 W.N.A.Sulaiman N.R.Jamil 《Geoscience Frontiers》 SCIE CAS CSCD 2019年第2期389-403,共15页
The devastating effect of soil erosion is one of the major sources of land degradation that affects human lives in many ways which occur mainly due to deforestation, poor agricultural practices, overgrazing,wildfire a... The devastating effect of soil erosion is one of the major sources of land degradation that affects human lives in many ways which occur mainly due to deforestation, poor agricultural practices, overgrazing,wildfire and urbanization. Soil erosion often leads to soil truncation, loss of fertility, slope instability, etc.which causes irreversible effects on the poorly renewable soil resource. In view of this, a study was conducted in Kelantan River basin to predict soil loss as influenced by long-term land use/land-cover(LULC) changes in the area. The study was conducted with the aim of predicting and assessing soil erosion as it is influenced by long-term LULC changes. The 13,100 km^2 watershed was delineated into four sub-catchments Galas, Pergau, Lebir and Nenggiri for precise result estimation and ease of execution. GIS-based Universal Soil Loss Equation(USLE) model was used to predict soil loss in this study. The model inputs used for the temporal and spatial calculation of soil erosion include rainfall erosivity factor,topographic factor, land cover and management factor as well as erodibility factor. The results showed that 67.54% of soil loss is located under low erosion potential(reversible soil loss) or 0-1 t ha^(-1) yr^(-1) soil loss in Galas, 59.17% in Pergau, 53.32% in Lebir and 56.76% in Nenggiri all under the 2013 LULC condition.Results from the correlation of soil erosion rates with LULC changes indicated that cleared land in all the four catchments and under all LULC conditions(1984-2013) appears to be the dominant with the highest erosion losses. Similarly, grassland and forest were also observed to regulate erosion rates in the area. This is because the vegetation cover provided by these LULC types protects the soil from direct impact of rain drops which invariably reduce soil loss to the barest minimum. Overall, it was concluded that the results have shown the significance of LULC in the control of erosion. Maps generated from the study may be useful to planners and land use managers to take appropriate decisions for soil conservation. 展开更多
关键词 soil EROSION USLE Landuse/cover changes GIS MALAYSIA
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The Influence of Seasonal Snow on Soil Thermal and Water Dynamics under Different Vegetation Covers in a Permafrost Region 被引量:8
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作者 HANG Juan WANG Gen-xu +1 位作者 GAO Yong-heng WANG Yi-bo 《Journal of Mountain Science》 SCIE CSCD 2014年第3期727-745,共19页
Seasonal snow is one of the most important influences on the development and distribution of permafrost and the hydrothermal regime in surface soil. Alpine meadow, which constitutes the main land type in permafrost re... Seasonal snow is one of the most important influences on the development and distribution of permafrost and the hydrothermal regime in surface soil. Alpine meadow, which constitutes the main land type in permafrost regions of the Qinghai-Tibet Plateau, was selected to study the influence of seasonal snow on the temperature and moisture in active soil layers under different vegetation coverage. Monitoring sites for soil moisture and temperature were constructed to observe the hydrothermal processes in active soil layers under different vegetation cover with seasonal snow cover variation for three years from 2010 to 2012. Differences in soil temperature and moisture in areas of diverse vegetation coverage with varying levels of snow cover were analyzed using active soil layer water and temperature indices. The results indicated that snow cover greatly influenced the hydrothermal dynamics of the active soil layer in alpine meadows. In the snow manipulation experiment with a snow depth greater than 15 cm, the snow cover postponed both the freeze-fall and thawrise onset times of soil temperature and moisture in alpine LC(lower vegetation coverage) meadows and of soil moisture in alpine HC(higher vegetation coverage) meadows; however, the opposite response occurred for soil temperatures of alpine HC meadows,where the entire melting period was extended by advancing the thaw-rise and delaying the freeze-fall onset time of the soil temperature. Snow cover resulted in a decreased amplitude and rate of variation in soil temperature, for both alpine HC meadows and alpine LC meadows, whereas the distinct influence of snow cover on the amplitude and rate of soil moisture variation occurred at different soil layers with different vegetation coverages. Snow cover increased the soil moisture of alpine grasslands during thawing periods. The results confirmed that the annual hydrothermal dynamics of active layers in permafrost were subject to the synergistic actions of both snow cover and vegetation coverage. 展开更多
关键词 植被覆盖度 多年冻土地区 土壤温度 积雪变化 水分动态 季节性 土壤水分变化 高原多年冻土区
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Soil Organic Carbon Stock as Affected by Land Use/Cover Changes in the Humid Region of Northern Iran 被引量:3
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作者 Samereh FALAHATKAR Seyed Mohsen HOSSEINI +2 位作者 Abdolrassoul SALMAN MAHINY Shamsollah AYOUBI WANG Shao-qiang 《Journal of Mountain Science》 SCIE CSCD 2014年第2期507-518,共12页
This study was conducted to determine the changes in the soil carbon stocks as influenced by land use in a humid zone of Deylaman district(10,876 ha), a mountainous region of northern Iran. For this, land use maps wer... This study was conducted to determine the changes in the soil carbon stocks as influenced by land use in a humid zone of Deylaman district(10,876 ha), a mountainous region of northern Iran. For this, land use maps were produced from TM and ETM+ images for 1985, 2000 and 2010 years; and this was supplemented by field measurement of soil carbon in 2010. The results showed that the mean soil organic carbon(SOC) density was 6.7±1.8 kg C m-2, 5.2±3.4 kg C m-2 and 3.2±1.8 kg C m-2 for 0-20 cm soil layer and 4.8±1.9 kg C m-2, 3.1±2 kg C m-2 and 2.7±1.8 kg C m-2 for 20-40 cm soil layer in forest, rangeland and cultivated land, respectively. During the past 25 years, 14.4% of the forest area had been converted to rangeland; and 28.4% of rangelands had been converted to cultivated land. According to the historical land use changes in the study area, the highest loss of SOC stocks resulted from the conversion of the forest to rangeland(0.45×104 Mg C in 0-40 cm depth layer); and the conversion of rangeland to cultivated land(0.37×104 Mg C in 0-40 cm), which typically led to the loss of soil carbon in the area studied. The knowledge on the historical land use changes and its influence on overall SOC stocks could be helpful for making management decision for farmers and policy managers in the future, for enhancing the potential of C sequestration in northern Iran. 展开更多
关键词 土壤有机碳库 土地利用 覆盖变化 湿润地区 伊朗 土地利用变化 土壤碳储量 ETM图像 森林面积
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The Role of Cover Crops towards Sustainable Soil Health and Agriculture—A Review Paper 被引量:7
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作者 Parmodh Sharma Atinderpal Singh +4 位作者 Charanjit Singh Kahlon Amandeep Singh Brar Kulbhushan K. Grover Mahendra Dia Robert L. Steiner 《American Journal of Plant Sciences》 2018年第9期1935-1951,共17页
Cover crops are the plants which are grown to improve soil fertility, prevent soil erosion, enrichment and protection of soil, and enhance nutrient and water availability, and quality of soil. Cover crops provide seve... Cover crops are the plants which are grown to improve soil fertility, prevent soil erosion, enrichment and protection of soil, and enhance nutrient and water availability, and quality of soil. Cover crops provide several benefits to soils used for agriculture production. Cover crops are helpful in increasing and sustaining microbial biodiversity in soils. We summarized the effect of several cover crops in soil properties such as soil moisture content, soil microbial activities, soil carbon sequestration, nitrate leaching, soil water, and soil health. Selection of cover crops usually depends on the primary benefits which are provided by cover crops. Other factors may also include weather conditions, time of sowing, either legume or non-legume and timing and method of killing of a cover crop. In recent times, cover crops are also used for mitigating climate change, suppressing weeds in crops and increasing exchangeable nutrients such as Mg2+ and K+. Cover crops are also found to be economical in long-term experiment studies. Although some limitations always come with several benefits. Cover crops have some problems including the method of killing, host for pathogens, regeneration, and not immediate benefits of using them. Despite the few limitations, cover crops improve the overall health of the soil and provide a sustainable environment for the main crops. 展开更多
关键词 cover CROPS SUSTAINABLE AGRICULTURE soil HEALTH Legumes soil Properties
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Effect of Rye and Mix Cover Crops on Soil Water and Cotton Yield in a Humid Environment
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作者 José O. Payero Michael W. Marshall +2 位作者 Rebecca H. Davis Joe Bible Nathaniel Nemire 《Open Journal of Soil Science》 2021年第5期271-284,共14页
In recent years, the use of cover crops is becoming a popular technology among growers in many regions of the United States, which is expected to deliver various benefits such as improving soil health, increasing soil... In recent years, the use of cover crops is becoming a popular technology among growers in many regions of the United States, which is expected to deliver various benefits such as improving soil health, increasing soil organic matter, controlling weeds, and helping conserve soil water and nutrients. Although expecting these benefits seems reasonable, it is challenging to know how much of these benefits to expect under specific situations. The potential effect of cover crops on soil water conservation is especially significant because of the documented impact of soil water on crop yield, especially for dryland cropping systems. Some researchers have found that planting a cover crop tended to increase soil water, while others have reported the opposite effect. Information on the impact of cover crops on soil water in cotton (<em>Gossypium hirsutum</em> L.) production systems in South Carolina is currently lacking. Therefore, the objective of this study was to quantify the effect of cover crops on soil water and cotton yield. A field experiment was conducted in South Carolina during winter, spring, and summer of 2015, with three cover crop treatments. The treatments included: 1) rye (<em>Secale cereale </em>L.), planted alone;2) a mix of six cover crop species;and 3) a control treatment with no-cover. The cover crop was established in the winter, terminated in the spring, and cotton was grown during the summer. Soil water was measured at different depths using capacitance probes and a neutron probe. Our results showed no significant differences in soil water and cotton yield among the cover crop treatments. These results suggest that under the humid conditions of this study, any short-term effect of the cover crop on soil water was masked by timely rain. 展开更多
关键词 soil Moisture soil Water cover Crop COTTON SENSORS
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Cover Crop Effects on Near-Surface Soil Aggregate Stability in the Southern Mississippi Valley Loess (MLRA 134)
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作者 Chandler Arel Kristofor R. Brye +1 位作者 Matt Fryer Mike Daniels 《Agricultural Sciences》 2022年第6期741-757,共17页
The use of cover crops (CC) during the agricultural fallow period has been shown to help alleviate soil compaction and provide stabilizing effects against soil erosion. These benefits are particularly important as man... The use of cover crops (CC) during the agricultural fallow period has been shown to help alleviate soil compaction and provide stabilizing effects against soil erosion. These benefits are particularly important as many of the silty, loess-derived soils of the major land resource area (MLRA) 134, the Southern Mississippi Valley Loess, have large erosion potentials. This study evaluated the effects of CC and no-cover crop (NCC) treatments on a selection of silt-loam soils in MLRA 134. Treatments were implemented during Fall 2018 and Fall 2019 and consisted of a range of CC species. Soil samples from the top 10 cm were collected to evaluate a suite of soil properties. Soil texture, pH, soil organic matter, and Mehlich-3 extractable Mg, Na, and Ca were unaffected (P > 0.05) by CC treatment. Total water-stable aggregate concentration was unaffected (P > 0.05) by CC treatment and soil depth (i.e., 0 - 5 and 5 - 10 cm). Soil bulk density was greater (P &#8226;cm<sup>&#8722;3</sup>) than under CC treatment (1.24 g&#8226;cm<sup>&#8722;3</sup>). Water-stable aggregate concentration was unaffected (P > 0.05) by CC treatment and soil depth, but was 21.5 times greater (P &#8226;g<sup>&#8722;1</sup>) than in the > 4-mm (0.05 g&#8226;g<sup>&#8722;1</sup>) size class. Study results indicate that, even among sites with large variability, CC can have consistent, short-term, positive effects on soil properties, but a long-term commitment to continuous, annual cover crops is necessary for the full realization of potential benefits. 展开更多
关键词 soil Erosion cover Crops soil Properties soil Aggregate Stability
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Influence of Tillage and Deep Rooted Cool Season Cover Crops on Soil Properties, Pests, and Yield Responses in Cotton 被引量:2
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作者 Michael W. Marshall Phillip Williams +4 位作者 Ali Mirzakhani Nafchi Joe Mario Maja Jose Payero John Mueller Ahmad Khalilian 《Open Journal of Soil Science》 2016年第10期149-158,共11页
Soil compaction is a significant problem in the Southeastern USA. This compacted zone or hardpan limits root penetration below this layer and reduces potential yield and makes plants more susceptible to drought induce... Soil compaction is a significant problem in the Southeastern USA. This compacted zone or hardpan limits root penetration below this layer and reduces potential yield and makes plants more susceptible to drought induced stresses. Soil compaction in this region is managed using costly annual deep tillage at or before planting and there is a great interest in reducing and/or eliminating annual tillage operations to lower production costs. Deep rooted cool season cover crops can penetrate this compacted soil zone and create channels, which cash crop roots, such as cotton, could follow to capture moisture and nutrients stored in the subsoil. The cool season cover crop roots would reduce the need for annual deep tillage prior to planting, increases soil organic matter, which provides greater water infiltration and available water holding capacity. Field studies were conducted for two years with three different soil series to determine the effects of tillage systems and cool season cover crops on the soil chemical and physical properties, yield responses, and pest pressure. Results showed that cool season cover crops significantly reduced soil compaction, increased cotton lint yield and soil moisture content, reduced nematode population densities, and increased soil available P, K, Mn, and organic matter content compared to the conventional no-cover crop. 展开更多
关键词 cover Crop COTTON soil Compaction Nematodes soil Water Content TILLAGE
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Impacts of snow cover and frozen soil in the Tibetan Plateau on summer precipitation in China
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作者 Rong Gao HaiLing Zhong +1 位作者 WenJie Dong ZhiGang Wei 《Research in Cold and Arid Regions》 2011年第6期491-497,共7页
This paper presents an analysis of the mechanisms and impacts of snow cover and frozen soil in the Tibetan Plateau on the sum- mer precipitation in China, using RegCM3 version 3.1 model simulations. Comparisons of sim... This paper presents an analysis of the mechanisms and impacts of snow cover and frozen soil in the Tibetan Plateau on the sum- mer precipitation in China, using RegCM3 version 3.1 model simulations. Comparisons of simulations vs. observations show that RegCM3 well captures these impacts. Results indicate that in a more-snow year with deep frozen soil there will be more precipita- tion in the Yangtze River Basin and central Northwest China, western Inner Mongolia, and Xinjiang, but less precipitation in Northeast China, North China, South China, and most of Southwest China. In a less-snow year with deep frozen soil, however, there will be more precipitation in Northeast China, North China, and southern South China, but less precipitation in the Yangtze River Basin and in northern South China. Such differences may be attributed to different combination patterns of melting snow and thawing frozen soil on the Plateau, which may change soil moisture as well as cause differences in energy absorption in the phase change processes of snow cover and frozen soil. These factors may produce more surface sensible heat in more-snow years when the fi'ozen soil is deep than when the frozen soil is shallow. The higher surface sensible heat may lead to a stronger updraft over the Plateau, eventually contributing to a stronger South Asia High and West Pacific Subtropical High. Due to different values of the wind fields at 850 hPa, a convergence zone will form over the Yangtze River Basin, which may produce more summer pre- cipitation in the basin area but less precipitation in North China and South China. However, because soil moisture depends on ice content, in less-snow years with deep frozen soil, the soil moisture will be higher. The combination of higher frozen soil moisture with latent heat absorption in the phase change process may generate less surface sensible heat and consequently a weaker updraft motion over the Plateau. As a result, both the South Asia High and the West Pacific Subtropical High will be weaker, hence caus- ing more summer precipitation in northern China but less in southem China. 展开更多
关键词 Tibetan Plateau snow cover fi'ozen soil summer precipitation
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Microbiological Assessment of Soil Planted with Cover Crops, and Soybean and Maize in Succession
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作者 Jaqueline Vanelli Edleusa Pereira Seidel +6 位作者 José Renato Stangarlin Marcos Cesar Mottin Pablo Wenderson Ribeiro Coutinho Nicanor Pilarski Henquemeier Danielle Acco Cadorin Jucenei Fernando Frandaloso André Luiz Alves 《American Journal of Plant Sciences》 2018年第4期659-666,共8页
This study aimed to assess the population density of nematodes and mycorrhizal soil fungi, in areas cultivated with oats, brachiaria, forage and white lupine, as well as in maize and soybean crops in succession, in or... This study aimed to assess the population density of nematodes and mycorrhizal soil fungi, in areas cultivated with oats, brachiaria, forage and white lupine, as well as in maize and soybean crops in succession, in order to generate a microbiological indicator of soil quality. In order to assess nematode and arbuscular mycorrhizal fungi (AMF) population densities, the experiment was performed in two stages: the first assessment was performed in the area where different cover crops were planted, in five seasons (0, 60, 90, 120, 150 days after sowing—DAS). In the second stage, soybean and maize crops in succession were assessed. According to the results, free-living nematodes and arbuscular mycorrhizal fungi population densities were not affected by the cover crop species used and, therefore, these can be grown prior to soybean and corn crops, without impact to free-living nematodes and AMF. The largest population of saprophyte nematodes and AMF occurred at 90 days. The cultivation of soybean and corn did not influence the number of free-living nematodes, but influenced the number of arbuscular mycorrhizal fungi. The highest numbers of mycorrhizal fungi Gigaspora margarita and Glomus macrocarpum were found in maize. 展开更多
关键词 cover CROPS MICROBIAL Biomass soil Management MYCORRHIZAL FUNGI
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Research on the Optimal Vegetation Cover for Remote Sensing Assessment of Soil Erosion Risk Using the Temporal Matching Relationship between Rainfall and Vegetation
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作者 Jianfeng Liu Xiwang Zhang 《Journal of Geoscience and Environment Protection》 2019年第2期22-36,共15页
Vegetation cover derived from remote sensing image is widely used for soil erosion risk assessment, but there is no clear guideline to select the most appropriate temporal satellite data. It is common practice that sa... Vegetation cover derived from remote sensing image is widely used for soil erosion risk assessment, but there is no clear guideline to select the most appropriate temporal satellite data. It is common practice that satellite data during growing season are randomly selected and used in soil erosion risk assessment. However, the effectiveness of vegetation in protecting the soil is quite different even if it is the same growing season since vegetation covers change as they grow. This article aims to provide a method of choosing optimal vegetation cover for studying soil erosion risk using remote sensing, that is, the vegetation cover in the most appropriate temporal period. Based on the temporal relationship of the two most active impact factors, rainfall and vegetation, an index of RV is developed and used to indicate the relative erosion risk during the year. The results show that annual variation of rainfall is significant, and vegetation is relatively stable, resulting in their matching relationship is different in each year. The correlation coefficient reaches 0.89 between RV and real sediment transport during the period when rainfall can cause soil erosion. In other words, RV is a good indicator of soil erosion. Therefore, there is a good correlation between RV maximum and the optimal vegetation cover, which can help facilitate erosion research in the future, showing good potential for successful application in other places. 展开更多
关键词 OPTIMAL VEGETATION cover Remote Sensing soil EROSION Risk TEMPORAL Matching Relationship
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Assessing the Effects of Land-Use and Land Cover Change and Topography on Soil Fertility in Melka Wakena Catchment of Sub-Upper Wabe-Shebelle Watershed, South Eastern Ethiopia
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作者 Hussein Hayicho Mersha Alemu Haji Kedir 《Journal of Environmental Protection》 2019年第5期672-693,共22页
This study was conducted in Melka Wakena catchment;south eastern Ethiopia to assess land use/cover change (LULCC) and topographic elevation effect on selected soil quality/fertility parameters. 144 soil samples collec... This study was conducted in Melka Wakena catchment;south eastern Ethiopia to assess land use/cover change (LULCC) and topographic elevation effect on selected soil quality/fertility parameters. 144 soil samples collected from 0 - 30 cm depth under three land cover types across three elevation gradients were analysed for selected soil quality/fertility parameters. Data were statistically analyzed using analysis of variance (ANOVA) and mean comparisons were made using Least Significant Difference (LSD). The soil properties examined generally showed significant variations with respect to land-use/land cover changes and elevation. Soil particles, soil organic carbon, total N, pH, available phosphorus, potassium and calcium content significantly decreased as forestland is converted into cropland/grassland. Heaviest soil deterioration was recorded in soils under cropland and followed by grassland soils. The conversion of natural forest to different land uses without proper soil conservation and management practices resulted in the overall decline of soil fertility quality. Thus, integrated land resource management approach is indispensable for sustaining agricultural productivity and the environmental health of the Melka Waken a catchment. 展开更多
关键词 Land Use/cover Resource Management soil QUALITY Spatial Variation Topographic ELEVATION soil QUALITY Parameters
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