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Soil nutrient loss due to tuber crop harvesting and its environmental impact in the North China Plain

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Journal of Integrative Agriculture 2016年第7期15卷 1612-1624页

作者： YU Han-qing LI Yong ZHOU Na Adrian Chappell LI Xiao-yu jean poesen Agricultural Clean Watershed Research Group Institute of Environment and Sustainable Development in AgricultureChinese Academy of Agricultural Sciences(CAA S)Beijing 100081P.R.China CSIRO Land&Water National Research Flagship Canberra ACT 2601Australia Division of Geography KU LeuvenHeverlee 3001Belgium

Soil loss due to crop harvesting （SLCH） is a soil erosion process that signiifcantly contributes to soil degradation in crop-lands. However, little is known about soil nutrient losses caused by SLCH and its environmental impacts. In the North China Plain area, we measured the losses of soil organic carbon （SOC） and nitrogen as wel as phosphorus due to SLCH and assessed their relationship with soil particle size composition, agronomic practices and soil moisture content. Our results show that the losses by harvesting potato of SOC, total nitrogen （TN）, available nitrogen （AN）, available phosphorus （AP） and total phosphorus （TP） were 1.7, 1.8, 1.8, 15.9 and 14.1 times compared by harvesting sweet potato, respectively. The variation of SOC, N and P loss by SLCH are mainly explained by the variation of plant density （PD）（17–50%）, net mass of an individual tuber （Mcrop/p）（16–74%）, soil clay content （34–70%） and water content （19–46%）. Taking into account the current sewage treatment system and the ratio of the nutrients adhering to the tubers during transportation from the ifeld （NTRP/SP）, the loss of TN and TP by harvesting of potato and sweet potato in the North China Plain area amounts to 3% N and 20% P loads in the water bodies of this region. The fate of the exported N and P in the sewage treatment system ultimately controls the contribution of N and P to the polution of lakes and rivers. Our results suggest that a large amount of SLCH-induced soil nutrient export during transportation from the ifeld is a potential polutant source for agricultural water for vast planting areas of tuber crops in China, and should not be overlooked.

关键词： soil nutrient losses potato sweet potato crop harvesting water polution

Monitoring gully erosion in the European Union: A novel approach based on the Land Use/Cover Area frame survey (LUCAS)

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International Soil and Water Conservation Research 2022年第1期10卷 17-28页

作者： Pasquale Borrelli jean poesen Matthias Vanmaercke Cristiano Ballabio Javier Hervas Michael Maerker Simone Scarpa Panos Panagos Department of Earth and Environmental Sciences University of PaviaVia Ferrata127100PaviaItaly Department of Biological Environment Kangwon National UniversityChuncheon24341Republic of Korea Department of Earth and Environmental Sciences KU LeuvenBelgium Faculty of Earth Sciences and Spatial Management Maria-Curie Sklodowska UniversityLublinPoland Departement de Geographie Universite de LiegeLiegeBelgium European Commission Joint Research Centre(JRC)IspraItaly

The European Commission's Thematic Strategy for Soil Protection(COM(2012)46)identified soil erosion as an important threat to European Union's(EU)soil *** erosion is an important but hitherto poorly understood component of this *** we present the results of an unprecedented attempt to monitor the occurrence of gully erosion across the EU and *** integrate a soil erosion module into the 2018 LUCAS Topsoil Survey,which was conducted to monitor the soil health status across the EU and to support actions to prevent soil *** discuss and explore opportunities to further improve this *** 2018 LUCAS Topsoil Survey consisted of soil sampling(0-20 cm depth)and erosion observations conducted in ca.10%(n=24,759)of the 238,077 Land Use/Cover Area frame Survey(LUCAS)2018 in-field survey *** erosion channels were detected for ca.1%(211 sites)of the visited LUCAS Topsoil ***(false positives,2.5%)and omission errors(false negatives,5.6%)were found to be low and at a level that could not compromise the representativeness of the gully erosion ***,the findings indicate that the tested 2018 LUCAS Topsoil in-field gully erosion monitoring system is effective for detecting the incidence of gully *** morphogenesis of the mapped gullies suggests that the approach is an effective tool to map permanent gullies,whereas it appears less effective to detect short-lived forms like ephemeral *** patterns emerging from the LUCAS Topsoil field observations provide new insights on typical gully formation sites across the EU and *** can help to design further targeted research *** extension of this approach to all LUCAS sites of 2022 would significantly enhance our understanding of the geographical distribution of gully erosion processes across the *** every three years,LUCAS soil erosion surveys would contribute to assess the state of gully erosion in the EU over *** will also enable m

关键词： Soil erosion Soil Concentrated flow erosion Google earth Earth observations

Changes in land use/cover mapped over 80 years in the Highlands of Northern Ethiopia

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Journal of Geographical Sciences 2018年第10期28卷 1538-1559页

作者： ETEFA Guyassa Amaury FRANKL Sil LANCKRIET BIADGILGN Demissie GEBREYOHANNES Zenebe AMANUEL Zenebe jean poesen Jan NYSSEN Department of Geography Ghent University Department of Land Resources Management and Environmental Protection Mekelle University Research Foundation Flanders (FWO) Department of Geography and Environmental Studies Mekelle University Institute of Geo-information and Earth Observation Sciences Mekelle University Division of Geography Department of Earth and Environmental Sciences

Despite many studies on land degradation in the Highlands of Northern Ethiopia, quantitative information regarding long-term changes in land use/cover(LUC) is rare. Hence, this study aims to investigate the LUC changes in the Geba catchment(5142 km2), Northern Ethiopia, over 80 years(1935–2014). Aerial photographs(APs) of the 1930 s and Google Earth(GE) images(2014) were used. The point-count technique was utilized by overlaying a grid on APs and GE images. The occurrence of cropland, forest, grassland, shrubland, bare land, built-up areas and water body was counted to compute their fractions. A multivariate adaptive regression spline was applied to identify the explanatory factors of LUC and to create fractional maps of LUC. The results indicate significant changes of most types, except for forest and cropland. In the 1930 s, shrubland(48%) was dominant, followed by cropland(39%). The fraction of cropland in 2014(42%) remained approximately the same as in the 1930 s, while shrubland significantly dropped to 37%. Forests shrank further from a meagre 6.3% in the 1930 s to 2.3% in 2014. High overall accuracies(93% and 83%) and strong Kappa coefficients(89% and 72%) for point counts and fractional maps respectively indicate the validity of the techniques used for LUC mapping.

关键词： fractional map Google Earth land use/cover multivariate adaptive regression Italian aerial photographs

Effectiveness of measures aiming to stabilize urban gullies in tropical cities:Results from field surveys across ***

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International Soil and Water Conservation Research 2023年第1期11卷 14-29页

作者： Eric Lutete Landu Guy Ilombe Mawe Fils Makanzu Imwangana Charles Bielders Olivier Dewitte jean poesen Aurélia Hubert Matthias Vanmaercke Department of Geography(U.R.SPHERES) University of LiegeClos Mercator 34000LiègeBelgium Department of Geoscience University of KinshasaKinshasa Mont-AmbaCongo Department of Natural resources management University of KinshasaKinshasa Mont-AmbaD.R Congo Department of Geology Oficial University of de BukavuCongo Geomorphology and Remote Sensing Laboratory Center for Geological and Mining ResearchCongo Earth and Life Institute-Environmental Sciences Universite catholique de LouvainCroix du sud 2L7.05.021348Louvain-la-NeuveBelgium Royal Museum for Central Africa Leuvensesteenweg 13B-3080TervurenBelgium Department of Earth and Environmental Sciences KU LeuvenCelestijnenlan 200E3001HeverleeBelgium Institute of Earth and Environmental Sciences Maria-Curie Sklodowska University(UMCS)Krasnicka 2D20-718LublinPoland

Urban gullies are a rapidly growing concern in many tropical cities of the Global *** measures are already implemented for their ***,an overview of these measures and their overall effectivenesss is currently *** aim at addressing this gap by documenting existing ini-tiatives to stabilize urban gullies in *** and assessing their overall *** this end we conducted extensive field campaigns in Kinshasa,Kikwit and Bukavu and combined our terrain obser-vations with data on gully expansion rates(derived from series of satellite imagery).In total,we char-acterized present and past stabilization initiatives for 398 urban *** 69 of these gullies,the effect of a specific measure on gully expansion rates could be *** show that for the large ma-jority of gullies,various measures have been ***,these are mainly ad-hoc measures installed by the affected *** structural measures based on larger engineering works were observed for only 20-30%of *** huge efforts invested in the installation of measures strongly contrast with their overall low impact Among all strategies,only the deviation of runoff resulted in significantly lower expansion rates after *** numerous initiatives that rely on the sparse means available seem to have limited *** does not imply,however,that they are completely ineffective and should be *** on our findings,we formulate recommendations for further research on how to effectively prevent and stabilize urban gullies,taking into account the difficult environmental and socio-economic context.

关键词： Gully expansion rate Head and channel measures Catchment measures Global South Urban hazard

Global analysis of cover management and support practice factors that control soil erosion and conservation

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International Soil and Water Conservation Research 2022年第2期10卷 161-176页

作者： Kindiye Ebabu Atsushi Tsunekawa Nigussie Haregeweyn Mitsuru Tsubo Enyew Adgo Ayele Almaw Fenta Derege Tsegaye Meshesha Mulatu Liyew Berihun Dagnenet Sultan Matthias Vanmaercke Panos Panagos Pasquale Borrelli Eddy J.Langendoen jean poesen Arid Land Research Center Tottori University1390 HamasakaTottori680-0001Japan College of Agriculture and Environmental Sciences Bahir Dar UniversityP.O.Box 1289Bahir DarEthiopia International Platform for Dryland Research and Education Tottori UniversityTottori680-0001Japan Department of Land Resources Management and Environmental Protection Mekelle UniversityP.O.Box 231MekelleEthiopia Faculty of Civil and Water Resource Engineering Bahir Dar Institute of TechnologyBahir Dar UniversityP.O.Box 26Bahir DarEthiopia Department of Earth and Environmental Sciences KULeuven3001HeverleeBelgium University of Liege Department of Geography(U.R.SPHERES)Clos Mercator 34000LiègeBelgium European Commission Joint Research Centre(JRC)Ispra(VR)21027Italy Environmental Geosciences University of BaselBasel4056Switzerland National Sedimentation Laboratory Agricultural Research ServiceUnited States Department of AgricultureUSA Faculty of Earth Sciences and Spatial Management Maria-Curie Sklodowska UniversityKrasnicka 2D20-718LublinPoland

Cover management and support practices largely control the magnitude and variability of soil *** soil erosion models account for their importance(particularly by C-and P-factors in the Revised Universal Soil Loss Equation),obtaining spatially explicit quantitative field data on these factors remains ***,also our insight into the effects of soil conservation measures at larger spatial scales remains *** analyzed the variation in C-and P-factors caused by human activities and climatic variables by reviewing 255 published articles reporting measured or calculated C-and P-factor *** found a wide variation in both factor values across climatic zones,land use or cover types,and support *** average C-factor values decreased from arid(0.26)to humid(0.15)climates,whereas the average P-factor values increased(from 0.33 to 0.47,respectively).Thus,support practices reduce soil loss more effectively in drylands and drought-prone *** global average C-factor varies by one order of magnitude from cropland(0.34)to forest(0.03).Among the major crops,the average C-factor was highest for maize(0.42)followed by potato(0.40),among the major orchard crops,it was highest for olive(0.31),followed by vineyards(0.26).The P-factor ranged from 0.62 for contouring in cropland plots to 0.19 for trenches in uncultivated *** C-factor results indicate that cultivated lands requiring intensive site preparation and weeding are most vulnerable to soil loss by sheet and rill *** low P-factor for trenches,reduced tillage cultivation,and terraces suggests that significantly decreased soil loss is possible by implementing more efficient management *** results improve our understanding of the variation in C-and P-factors and support large-scale integrated catchment management interventions by applying soil erosion models where it is difficult to empirically determine the impact of particular land use or cover types and support

关键词： Climate regimes Drought-prone Erosion modeling Land use Soil conservation

Decentralised Governance of Wetland Resources in the Lake Victoria Basin of Uganda

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Natural Resources 2013年第1期4卷 55-64页

作者： Alice Nakiyemba Were Moses Isabirye jean poesen Miet Maertens Jozef Deckers Erik Mathijs Department of Earth and Environmental Sciences Katholieke Universiteit Leuven Leuven Belgium Department of Earth and Environmental Sciences Katholieke Universiteit Leuven Leuven Belgium Faculty of Natural Resources and Environment Busitema University Namasagali Campus Tororo Uganda Faculty of Natural Resources and Environment Busitema University Namasagali Campus Tororo Uganda

Recent studies on decentralized wetland governance in Uganda have focused mainly on the relationship between central and local governments. Less attention has been given to the relationship between agricultural systems, local governments, and water bodies. This study aims at assessing decentralized wetlands governance in the upper river Rwizi and Iguluibi micro catchments, Lake Victoria Basin Uganda, in relation to farming practices. Qualitative and quantitative methods were used to provide a comprehensive understanding of the contribution of decentralized governance to the management of wetlands resources. Quantitative survey data were analyzed using descriptive summary statistics with the help of Statistical package for Social Sciences (SPSS) soft ware. Qualitative data analysis involved the categorization of verbal and behavioral data for purposes of classification with the use of Nvivo soft ware. Data were analyzed at two levels: the descriptive level of analysis which is the account of the data in terms of what was said, documented or observed with nothing assumed about it. The second level of analysis was interpretive, where data is transformed into what is meant by the responses and conclusions are drawn. All recorded interviews were transcribed into a written report. Findings revealed that decentralized wetlands governance has brought ecosystem services nearer to communities in form of community-based management planning. However, results indicated inadequate institutional capacity, knowledge gaps of existing legal frameworks, limited political support and accountability for local leaders, lack of cooperation and coordination, and inadequate funding. In all, the policy has not fully realized its intended outcomes.

关键词： Agricultural Systems Decentralized Governance Lake Victoria Wetland Degradation Uganda