Page:The Olive Its Culture in Theory and Practice.djvu/58

48 the complete development of the plant, and the abundant production of the best quality of fruit. Hence, it is safe to assume, that the olive prefers a soft, friable, moderately cool soil, and one rich in lime and potash; a permeable soil, such as a limey clay of medium consistency, not inclined to either dryness or humidity. The roots would then encounter no obstacle in extending themselves, and the air and moisture could circulate sufficentlysufficiently [sic]. Lime, abounding phosphates, magnesia, with an abundance of silicates of alum and mercury, and a sufficiency of potash and soda, are the chemical and physical requisites which this tree will find most advantageous to its development, and cause it to produce abundantly, and, provided other circumstances are equal, give the very best oil. It is seen that the olive will flourish wherever its roots will penetrate easily, and there is no deficiency of lime and alkali, such as a loose soil of rocky clay, or sand of volcanic or granite formation. But, while the olive will subsist on many different soils, and prosper in several, it is not to be concluded that it may be condemned to bare, sterile, impoverished ground, where not even a forest tree would be nourished.

The latitude must largely guide one in selecting the kind of soil for an olive orchard.

In Andalucia and Valencia, in southern Spain, the mean summer temperature is as high as eighty-two degrees. There, they hold red soils in very low estimation, and prefer the light colored or white; considering that the red attracts too much heat, and requires too much fertilization and irrigation, without which the tree gives no fruit in that latitude. There, a very porous soil, giving free passage to moisture, and evaporating freely, requires repeated fertilizing and watering. Going north in central Spain, the light red soil with a porous tendency to carry off the frequent rains, is preferred, and the white is altogether condemned. Still further north, the dark red and very porous soils are exclusively used. The calcareous soils, through their action on the natural and artificial fertilizers, quickly put into circulation the elements of nutrition of the