  An almost K\"ahler structure is {\it extremal} if the Hermitian scalar
curvature is a Killing potential [29]. When the almost complex structure is
integrable it coincides with extremal K\"ahler metric in the sense of Calabi
[8]. We observe that the existence of an extremal {\it toric} almost K\"ahler
structure of involutive type implies uniform K-stability and we point out the
existence of a formal solution of the Abreu equation for any angle along the
invariant divisor. Applying the recent result of Chen--Cheng [10] and He [27],
we conclude that the existence of a compatible extremal toric almost K\"ahler
structure of involutive type on a compact symplectic toric manifold is
equivalent to its relative uniform $K$--stability (in a toric sense). As an
application, using [5], we get the existence of an extremal toric K\"ahler
metric in each K\"ahler class of $\mathbb{P}(\mathcal{O}\oplus \mathcal{O}(k_1)
\oplus \mathcal{O}(k_2))$.
