The electric field is defined as the electric force per unit of charge. The direction of the field is taken as the direction of the force it would exert on a positive test load. An electric field is always directed from its positive charge to the negative. Under this condition if the terrestrial electric field is pointing towards the ground, the terminal that is pointing is the negative and that of its surface is the positive. This implies that the sign of the charge of the electric field of the soil will be negative.
