The roots of trees and plants serve the purpose of holding the top erect and to supply water, with its dissolved elements, for sustaining growth of the tree or plant. The deep roots take up the water mainly and the surface-roots largely take up nitrates and other essentials of growth. The soil conditions have much to do with the vigorous growth of roots and the closely related tops. In Nature the extension of roots in the soil favor the admission of the oxygen of. the air, and the leaves that accumulate give the needed supply of leaf-mould and nitrogen required for healthy growth. On the other hand, the clean culture of the orchard and small fruit-plantation without the application of barn-yard manure or other organic material, will soon so change the mechanical condition of the soil that air cannot enter to give life and growth to the protoplasm of newly formed and growing roots. The continued clean culture without the application of vegetable matter will soon take the humus from the soil and starve the roots and whole plant-growth by lessening the supply of nitric acid and its combination with alkalies, such as nitrate of soda and other useful plant-nutrients.