October 4th, 2004Charge transport in the hole-doped quasi-1D model system Y2−xCaxBaNiO5 (x leq 0.15) is investigated in the 50-300 K temperature range. The resistivity temperature dependence is characterized by a constant activation energy Ea/kBsim 1830 K at room temperature while Ea decreases upon cooling. We suggest that Ea measures the binding energy of the doped holes which form magneto-acoustic polarons when polarizing the neighboring Ni spins. A semi-classical model is proposed which allows to relate the electrical measurements and the bulk magnetic susceptibility. This model gives a picture of the spin-charge-lattice relation in this inhomogeneously doped quasi-1D system and explains its unusual one-particle charge excitation spectrum close to the Fermi level