CHAP. 7.—CROPS WHICH TEND TO IMPROVE THE LAND: CROPS WHICH EXHAUST IT.
Cato[2911] says, also, that there are some crops which tend to nourish the earth: thus, for instance, corn land is manured by the lupine, the bean, and the vetch; while, on the other hand, the chick-pea exercises a contrary influence, both because it is pulled up by the roots and is of a salt nature; the same is the case, too, with barley, fenugreek, and fitches, all of which have a tendency to burn up[2912] corn land, as, in fact, do all those plants which are pulled up by the roots. Take care, too, not to plant stone-fruits on corn land. Virgil[2913] is of opinion, also, that corn land is scorched by flax, oats, and poppies.