recalcitrant P, which is not extracted by NaHCO3. On the
other hand organic manure did not allow fertilizer P to
convert to an inorganic form and thus greater increases
in organic P in manured treatments confirm the findings.
Application of both manure and fertilizer N either alone
or in combination did not have any effect on residual P.
The sum of sequential analysis yielded a mean recovery
of 91.7% and 94.7% of the total P (Pt) estimated by acid
digestion in a separate analysis in surface and subsurface
layer, respectively. The P recovery obtained in present
study is almost similar to that earlier obtained by Hedley
et al. (1982) and Singh et al. (2001a).
The sum of sequential analysis of different treatment
fractions of P and the total Pt analysis of subsurface (16–
30 cm) indicate that a part of applied fertilizer P had
migrated to the subsoil layer. For example, initially the