Phosphorous Fractions’ Distribution Of Nansi Lake Water Fluctuation Zone Soils

Phosphorus（P）is one of the mean factors which cause Eutrophication.The P in the Water-Level Fluctuating Zone is the potential threat leading to Eutrophication.Nansi Lake,a typical shallow lake in south Shandong Province,China,has a total surface area of 1,266 km² and is the largest and most important freshwater reservoir in northern China for the eastern route of the South-North Water Diversion project.Nansi lake is an important pivot lake of the South-to-North Water Diversion project.The Water-Level Fluctuating Zone near Nansi Lake will be formed when the South-North Water Diversion project begins to transport water flowing through the lake,which will impact the Water quality.The range of Nansi Lake Water-Level Fluctuating Zone was showed by Arcmap,and the P fractions’content and distribution were detected with the Standards Measurements and Testing Program of the European Commission（SMT protocol）.The correlations above the P fractions and mean soil properties were researched,and the potential to release P of different land uses and different kind of soils were analyzed.（1）The P fractions’dimensional differences of Nansi Lake Water-Level Fluctuating Zone is significant:The hige values of NaOH-P,HCl-P and IP in the Water-Level Fluctuating Zone of Nansi lake spread at south,their average values are 53.27mg?kg^-1,518.35 mg?kg^-1 and 532.79 mg?kg^-1.Their distributions are South>West>East.The TP showed West>South>East,and its average value around west is 811.77mg?kg^-1.The high values of OP spread at west,and its average value is 269.99 mg?kg^-1,and the distribution of OP is West>East>South.Around the South bank,the contents of TP,IP,NaOH-P,HCl-P and OP be lower from east to west.Around the west bank,all the P fractions are lower from middle to both north and south.Around the east bank,the TP and OP are higher from north to south,and the IP and HCl-P are higher from middle to both north and south,while there is no notable change of the NaOH-P.（2）Above the different P fractions,NaOH-P and IP show very significant positive correlation（P<0.01）,and the TP are positively and very significantly correlated with NaOH-P,HCl-P,IP and OP（P<0.01）.Above the P fractions and other soil properties,NaOH-P is positively and very significantly correlated with Feox（P<0.01）,andω_LOIOI is positively and very significantly correlated with NaOH-P,TP and OP（P<0.01）,and pH is negatively and significantly correlated with NaOH-P、ω_LOI（P<0.05）,and is positively and very significantly correlated with OP（P<0.01）.（3）According to the content of NaOH-P,The potential to release P of different land uses is Irrigated land>Aquaculture and Livestock breeding>Arbors.The potential to release P of different kinds of soil is Lime concretion black soil>Fluvo-aquic soil>Cinnamon soil.