We have studied the effect of adsorption and desorption of rod-like magnetic grains on the macroscopic properties of ferronematics in a ferronematic cell. An external magnetic field controls the equilibrium between ferroparticles in the bulk and those adsorbed on the cell surfaces. The magnetic field, can thus influence the anchoring and the nematic orientational texture. In the presence of ferroparticle adsorption, the segregation effect is diminished, and the system becomes less susceptible to bulk ferroparticle coagulation.