  Spin incommensurability has been recently experimentally discovered in the
hole-doped Ni-oxide chain compound $\rm Y_{2-x}Ca_x Ba Ni O_5$ (G. Xu {\it
al.}, Science {\bf 289}, 419 (2000)). Here a two orbital model for this
material is studied using computational techniques. Spin IC is observed in a
wide range of densities and couplings. The phenomenon originates in
antiferromagnetic correlations ``across holes'' dynamically generated to
improve hole movement, as it occurs in the one-dimensional Hubbard model and in
recent studies of the two-dimensional extended t-J model. The close proximity
of ferromagnetic and phase-separated states in parameter space are also
discussed.
