Fig. 3. Relationship between relative extractable soil (a) Mehlich 3-P, (b) iron-oxide strip extractable P (FeO-P), and (c) water-soluble P (WS-P) at 2 and 8 wk after treatment incorporation (for those samples that were significantly different between the two dates). The 1:1 line represents points in each relationship where no change in relative extractable P occurred between 2 and 8 wk.