Succession cropping cultivators

1245. Growing different crops in succession is a practice which every cultivator knows to be highly advantageous, though its beneficial influence has not yet been fully accounted for by chemists. The most general theory is, that though all plants will live on the same food, as the chemical constituents of their roots and leaves are nearly the same, yet that many species require particular substances to bring their seeds or fruits to perfection, as the analyses of these seeds or fruits often afford substances different from those which constitute the body of the plant.