Bremner J M. 1965. Inorganic forms of nitrogen. In: Black C A, ed., Methods of Soil Analysis. ASA and SSSA, Madison.pp. 1179–1237.Cheng B, Zhang Z, Chen L, Yuan Z h, Sun X R. 2005. Eutrophication of taihu lake and pollution from agricultural non-point sources in lake Taihu Basin. Journal of Agro-Environment Science, 24, 118–124. (in Chinese)Cheng H G, Yue Y, Yang S T, Hao F H, Yang Z F. 2006. An estimation and evaluation of non-point source (NPS) pollution in the Yellow River Basin. Acta Scientiae Circum Stantiae, 26, 384–391. (in Chinese) Dong Q. 2011. Non-point source pollution of nitrogenand phosphorus burthen in Benghe watershed of the Yimeng Mountanous, Shandong Province. MSc thesis. Shandong Agriculture Univeristy, China. (in Chinese) FAOSTAT. 2013. Agriculture data. Agricultural production. [2013-8-4]. http://faostat3.fao.org/download/Q/QV/EGee G W, Bauder J W. 1986. Particle-size analysis. In: Klute I A, ed., Methods of Soil Analysis. ASA and SSSA, Madison.pp. 383–411.Isabirye M, Ruysschaert G, Van linden L, Poesen J, Magunda M K, Deckers J. 2007. Soil losses due to cassava and sweet potato harvesting: A case study from low input traditional agriculture. Soil & Tillage Research, 92, 103.Jiang Y, Ma W, Pemg Q D, Luo H H. 2013. Calculation and analysis of water pollution load in Yanqi River Basin. Journal of China Institute of Water Resources and Hydropower Research, 11, 117–124. (in Chinese)Jin LY, Zhang G M, Tian H F. 2014. Current state of sewage treatment in China. Water Research, 66, 85–98.Koch H J. 2002. Cultural practice effects on soil tare. In: Proceedings of the 65th Institut International de Recherches Betteravières Congress. Brussels, Belgium. pp. 107-116.Kothyari B P, Verma P K, Joshi B K, Kothyari U C. 2004. Rainfall-runoff-soil and nutrient loss relationships for plot size areas of bhetagad watershed in Central Himalaya, India. Journal of Hydrology, 293, 137–150.Lei L G, Yuan H M. 2013. Chinese agriculture almanac. In: Commission Caye. 3rd ed. China Agricuture Press, Beijing, China. p. 203. (in Chinese)Liu Q C. 2004. Importance of sweet potato in the security of food and energy in China. Science & Technology Review, 9, 22–24.Liu Z D, Yu X G, Wang Z X. 2003. The current water pollution of Taihu drainage basin and the new management proposals. Journal of Natural Resources, 18, 467–474.Li Y, Ruysschaert G, Poesen J, Zhang Q W, Bai L Y, Li L, Sun L F. 2006. Soil losses due to potato and sugar beet harvesting in NE China. Earth Surface Processes and Landforms, 31, 1003–1016.Munodawafa A. 2007. Assessing nutrient losses with soil erosion under different tillage systems and their implications on water quality. Physics and Chemistry of the Earth, 32, 1135–1140.Murphy J, Riley J P. 1962. A modified single solution method for the determination of phosphate in natural water. Analytica Chimica Acta, 27, 31–36.Mwango S B, Msanya B M, Mtakwa P W, Kimaro D N, Deckers J, Poesen J, Lilanga S, Sanga R. 2015. Soil loss due to crop harvesting in Usambara mountains, Tanzania: The case of carrot, onion and potato. International Journal of Plant & Soil Science, 4, 18-28.NBSC (National Bureau of Statistics of China). 2013a. Anhui Statistical Yearbook. China Statistics Press, Beijing. (in Chinese) NBSC (National Bureau of Statistics of China). 2013b. Shandong Statistical Yearbook. China Statistics Press, Beijing. (in Chinese)Nelson D, Sommers L E. 1996. Total carbon, organic carbon, and organic matter: Laborat个ory methods. In: Sparks I D L, ed., Methods of Soil Analysis. SSSA Book Ser, Madison.pp. 961–1010.Niu Q. 2013. Current situation and suggestion of sweet potato seedling industry development in Daxing District of Beijing in China. China Agricultural Technology Extension, 29, 68–70. (in Chinese)NSRICAS (Nanjing Soil Research Institute CAS). 1978. Soils of China. Science Press, China. (in Chinese)Olson S R, Sommers L E. 1982. Phosphorus. In: Page A L, ed., Methods of Soil Analysis. ASA and SSSA, Madison, pp. 403–430.Patchett M R, Bee P M. 1998. Effects of plant population, variety and the use of cleaner loaders on soil tares in sugarbeet. Aspects of Applied Biology, 52, 165-167.Pennock D J, Lemmon D S, de Jong E. 1995. Cesium-137 measured erosion rates for five parent-material groups in southwestern Saskatchewan. Canadian Journal of Soil Science, 75, 205–210.Poesen J W A, Verstraeten G, Soenens R, Seynaeve L. 2001. Soil losses due to harvesting of chicory roots and sugar beet: An underrated geomorphic process? Catena, 43, 35–47.Ruysschaert G, Poesen J, Notebaert B, Verstraeten G, Govers G. 2008. Spatial and long-term variability of soil loss due to crop harvesting and the importance relative to water erosion: A case study from Belgium. Agriculture, Ecosystems and Environment, 126, 217–228.Ruysschaert G, Poesen J, Verstraeten G, Govers G. 2004. Soil loss due to crop harvesting: Significance and determining factors. Progress in Physical Geography, 28, 467–501.Ruysschaert G, Poesen J, Verstraeten G, Govers G. 2006. Soil losses due to mechanized potato harvesting. Soil & Tillage Research, 86, 52–72.Ruysschaert G, Poesen J, Verstraeten G, Govers G. 2007. Soil loss due to harvesting of various crop types in contrasting agro-ecological environments. Agriculture, Ecosystems and Environment, 120, 153–165.SAS Institute Inc. 2000. SAS/STAT User’s Guide, ver. 8. SAS Institute Inc, Cary, NC.Shi B L, You R L. 2010. Research of sweet potato and its development strategies in Henan Province. Resource Development & Market, 26, 331–333. (in Chinese)Smit A B, Struik P C, Van Niejenhuis J H. 1998. Prediction of various effects of harvest date in sugar beet growing. Journal of Agronomy and Crop Science, 180, 113–122.Song L C. 2013. China’s Meteorological Disaster Yearbook. China Meteorological Press, China. (in Chinese)Stengel A, Loury C. 1999. Contribution à la analyse des différences de tare terre de betterave sucrière en Europe du Nord. MSc thesis. Institut National Agronomique, Paris-Grignon. (in France) Su B L, Wang J P, Jia H F. 2006. Identification of non-point source pollution in the Miyun Reservoir watershed. Journal of Tsinghua University (Science and Technology), 46, 360–365. (in Chinese)Topp G C, Davis J L, Annan A P. 1980. Electromagnetic determination of soil-water content - Measurements in coaxial transmission-lines. Water Resources Research, 16, 574–586.Tu?rul K M, ?çöz E, Perendecic N A. 2012. Determination of soil loss by sugar beet harvesting. Soil & Tillage Research, 123, 71–77.Vagstad N, Jansons, V, Loigu E, Deelstra J. 2000. Nutrient losses from agricultural areas in the Gulf of Riga drainage basin. Ecological Engineering, 14, 435–441.Vermeulen G D, Klooster J J, Sprong M C, Verwijs B R. 1997. Effect of straight and spiral sugar beet extraction paths and lift acceleration on soil tare and relative soil adherence. Netherlands Journal of Agriculture Sciences, 45, 163–184.Wang D H, Liang C H. 2002. Transportation of agriculture phosphorus and control to reduce the phosphorus loss to water: A review. Soil and Environmental Sciences, 11, 183–188.Wang D Z, Zhang Y C. 2010. Present situation investigation and analysis of sweet potato production and application in Anhui Province. Journal of Anhui Agricultural Sciences, 38, 10024–10025. (in Chinese)Wang X B, Oenema O, Hoogmoed W B, Perdok U D, Cai D X. 2006a. Dust storm erosion and its impact on soil carbon and nitrogen losses in northern China. Catena, 66, 221–227.Wang X H. 2006b. Study on non-point source pollution of nitrogen and phosphorus drainage evaluating and it’s controlling on in Chaohu watershed. MSc thesis. Hefei University of Technology, China. (in Chinese)Wortmann C S, Kaizzi C K. 1998. Nutrient balances and expected effects of alternative practices in farming systems of Uganda. Agriculture, Ecosystems and Environment, 71, 115–129.Wu L. 2012. Fate and transport of non-point source nitrogen, phosphorus and pesticide pollution in typical area of the three gorges reservoir area. PhD thesis. Chongqing University, Chongqing, China. p. 212. (in Chinese)Zhang S S, Liu L F. 2004. Production and research status and industry development strategy of sweet potato in Hebei Province. Rain Fed Crops, 24, 110–112. (in Chinese)Zhang Z L, Xin L J, Liang C L. 2007. The analysis of hydrological characteristics and processes of ecosystem in Lake Nansi during the past 50 years. Geographical Research, 26, 957–966. (in Chinese)Zhao Y C, Shi X Z, Yu D S, Wang H J, Sun W X. 2005. Uncertainty assessment of spatial patterns of soil organic carbon density using sequential indicator simulation, a case study of Hebei Province, China. Chemosphere, 59, 1527–1535.Zhou J H, Xie P Q, Li Y L, Zheng J W. 2013. The problems and Suggestions of seed potato development in Henan Province, China. China Seed Industry, 7, 51–53. (in Chinese)Ziibisch M A, Richterby C, Heiligtagb B, Schlottb R. 1995. Nutrient losses from cropland in the Central Highlands of Kenya due to surface runoff and soil erosion. Soil & Tillage Research, 33, 109–116. |