Justus von Liebig, generally credited as the “father of the fertilizer industry”, formulated the law of the minimum: if one crop nutrient is missing or deficient, plant growth will be poor, even if the other elements are abundant. Any deficiency of any critical element delays plant development. Once supply of that element is no longer the limiting factor, there is no benefit to increasing its supply. Another element will then be in the minimum supply and be the limiting factor. Liebig likens the potential of a crop to a barrel with staves of unequal length. The capacity of this barrel is limited by the length of the shortest stave (in this case, phosphorus) and can only be increased by lengthening that stave. When that stave is lengthened, another one becomes the limiting factor.