Transport measurements on thin films of NdNiO3 reveal a crossover to a regime of pronounced nonlinear conduction below the well-known metal-insulator transition temperature. The evolution of the transport properties at temperatures well below this transition appears consistent with a gradual formation of a gap in the holelike Fermi surface of this strongly correlated system. As T is decreased below the nominal transition temperature, transport becomes increasingly non-Ohmic, with a model of Landau-Zener breakdown becoming most suited for describing I(V) characteristics as the temperature approaches 2 K.