The rate of application of chemical fertilizers depends upon such factors as (1) the character of the soil, (2) the previous crop grown and the manner in which it was fertilized, (3) the moisture conditions, (4) the importance of early maturity, (5) the possibility of irrigation, (6) the amount of land available and (7) the character of the crop to be grown. Applications vary from a few hundred pounds to two or more tons to the acre. One ton to the acre for a single crop is considered liberal, although this amount is often exceeded. At Norfolk, Virginia, 3000 pounds are frequently applied during the season. While dangers attend the free use of fertilizers (109), the only sound business policy is to apply the various elements in fully sufficient quantities. Regarding this matter, Dr. Edward B. Voorhees says (Voorhees, Fertilizers, p. 264) : "Apply a reasonable excess of all the essential fertilizer constituents to all of the crops. Nevertheless, because of the peculiarities of growth of the different plants, as well as the different objects of their growth, distinctions should be made in reference to the kinds and amounts of plant food applied, and these conditions should be borne in mind, in order that the most profitable results may be secured." (See notes on fertilizers in Chapter XXI).