Page:Tree Crops; A Permanent Agriculture (1929).pdf/186

 Island, New Jersey, North Carolina, and of the Appalachian summits are shunned by the farmer as though they were the Sahara Desert, yet these sand barrens are often productive of many acorns—good carbohydrate nutriment.

It is not unnatural that the oak tree should render its greatest service to commercial agriculture in the modern world through the cork oak, the species which has the greatest number and variety of products.

The oak tree is the source of one of the chief exports and two of the important industries of Portugal. If I wanted to secure permanent and comfortable financial ease from agricultural land, few more secure bases need be sought than the undisturbed possession of a large tract of Portuguese land having a good stand of cork-oak trees (quercus suber) and evergreen-oak trees (quercus ilex). If the stand of trees were good, it would make little difference even if the land happened to be rough untillable hillsides. Such land would still yield its crops of cork and pork (the pork made of acorns). The virtues of the Portuguese cork forests are quadruple, and the forests are almost perpetual if given a little intelligent care.

With reasonable care, which consists of occasional cutting out of an undergrowth of bushes inedible to the goat, and occasional thinnings, the forest will live and reproduce itself for centuries and yield four kinds of income. The trees yield best of cork and acorns when the stand is not thick enough for the trees to crowd each other. Thinning to attain this end permits some forage for sheep and goats to grow beneath the trees. It is the common expectation that the pasturage income in a proper oak forest will pay for the labor of grubbing bushes, which, aside from fire protection, is the only maintenance charge. That leaves the other three sources of income—wood, cork, and pork—to offset interest and taxes and to make profit. The landlord's task is easy, as the pasture