九龙江口南港段潮滩区土壤/沉积物的磷素形态特征

Characteristics and Fractionation of Phosphorus in Soils and Sediments in Tidal Flat Area for Nangang Segment of Jiulongjiang Estuary

采用连续提取法对九龙江口南港河段潮滩区土壤和表层沉积物中的磷进行了连续提取和测定，同时对各土样中磷的有效性进行了分析．结果表明，土样中总磷、有效磷及不同形态磷的含量均表现出相同的变化趋势，由高到低依次为草滩〉沉积物〉竹林，磷的有效性为25．9%-29．9％，潜在的能被生物所利用的磷约占总磷的47．8％-64．5％；无机态磷是竹林土壤和沉积物磷素的主要存在形态，是有机磷的2～3倍，并呈现出以吸附态无机磷和铁结合态无机磷为主的特征，草滩土壤以有机磷形态为主．

The forms of phosphorus in the surface sediments and adjacent soils which was covered with bamboo and grass in tidal flat area for Nangang segment of Jinlongjiang Estuary, were investigated by sequential chemical extraction according to the scheme proposed by Jensen et al （1998）, meanwhile the effectiveness of phosphorus in these samples were analyzed. The results showed that the similar changed tendency for the contents of total phosphorus, effective phosphorus and different forms of phosphorus in all the samples were found, and they followed the order： grassplot 〉 sediments 〉 bamboo woodland. The availability of the phosphorus ranged from 25.9% to 29.9%, and the percentage for the bio-available phosphorus （BAP） of total phosphorus was the range of 47.8%-64.5%. The total phosphorus in the bamboo woodland and the sediment consisted mainly of inorganic phosphorus, which was chiefly composed by the loosely absorbed inorganic phosphorus （NaOH-P） and the iron-bonnd inorganic phosphorus （Fe-P）; and organic phosphorus was the primary form of total phosphorus in the grassplot.