Satisfactory results of automatic guidance of farm vehicles have been achieved in previous works as long as vehicles move without sliding, but unfortunately in agricultural applications, sliding always occurs inevitably which causes loss of accuracy. In this paper the problem of path following control of autonomous farm vehicles subject to sliding is addressed. To take sliding effects into account, a vehicle-oriented kinematic model is built in which sliding effects are integrated in the form of additive disturbances to the ideal kinematic model. By transforming the vehicle-oriented kinematic model into a perturbed chained system, a sliding mode controller, which is robust not only to the sliding effects but also to the input noise, is designed with the help of the natural algebraic structure of chained systems. Simulation results show that the proposed control law can guarantee high path-following accuracy even in the presence of sliding.