take up food in the soil or subsoil. Part of the food thus gathered in the subsoil helps to form roots in the cultivable area and part aids in forming top growth for pasture or for hay. If grazed down or if made into hay and fed so that the manure goes back upon the land the fertility of the same is increased in all leading essentials. This increase is partly made at the expense of the fertility in the subsoil. But the stores of fertility in the subsoil are such usually as to admit of thus being drawn upon indefinitely.

Clovers improve soils mechanically by rendering them more friable, by giving them increased power to hold moisture, and by improving drainage in the subsoil. Of course, they have not the power to do this equally, but they all have this power in degree and in all the ways that have been named.

Clovers send down a tap root into the soil and subsoil as they grow. From the tap roots branch off lateral roots in an outward and downward direction. From these laterals many rootlets penetrate through the soil. When the plants are numerous, these roots and rootlets fill the soil. When it is broken up, therefore, particles of soil are so separated that they tend to fall apart, hence the soil is always made more or less friable, even when it consists of the stiffest clays. The shade furnished by the clover also furthers friability. This friability makes the land easier to work, and it is also more easily penetrated by the roots of plants. The influence on aeration is also marked. The air can more readily penetrate through the interstices in the soil, and, in consequence, chemical changes in the soil favorable to plant growth are facilitated.