Relationships between various sediment P extractants
Although there were large variations between the P-extractants, they were significantly correlated with each other with r2values ranging from 0.68 to 0.95. As is observed, the figure of cluster analyses in the seven mentioned extractants no overall pattern of distance rather show the noticeable similarity from extractant to extractant (figure 5). Generally speaking, it seems that the four extractants (Colwell, Mehlich III, Olsen, and Morgan) extract P from equally the same pools and strong correspondingly is between Mehlich III and Olsen. Among the all extractants, 0.1 M NaOH showed quite different behavior and separated itself in a group (figure 5).