the
meetings of the Royal Society there.

THE PRESIDENT: We shall very much appreciate the opportunity of meeting
him.

We will now adjourn to the lecture hall, to hear Dr. J. Russell Smith.

NUT TREE CROPS AS A PART OF PERMANENT AGRICULTURE WITHOUT PLOWING

_Dr. J. Russell Smith, Professor of Economic Geography, Columbia
University, New York_

My first experience with nut culture was gained on the farm of a man I
knew more than 30 years ago. It was a truck farm not far from
Philadelphia near a boarding school which I infested and the farmer
complained that I infested the farm. The farm had its fence rows and
driveways lined with grafted chestnut trees bearing abundantly of large
fine nuts of European origin. It was remarkable how quickly they filled
my pockets. I usually succeeded in gathering them on the hundred per
cent basis.

I am interested in this subject today because of an innate love of trees
and because the development of a tree crop agriculture offers a way to
stop soil erosion. To me the worst of all economic sins is the
destruction of resources, and the worst of all resource destructions is
the destruction of the soil, our one great and ultimate resource. "After
man the desert" has been truly said too often of many old lands.

Soil cover is after all about the only thing that man has as a basis for
the support of his life on earth. All of our food depends directly or
indirectly upon plants.

In hilly countries there is usually but a thin layer of earth and rotton
rock between the surface of the field and the bed rock. It is a very
difficult problem to maintain this cover of earth and it is very easy to
lose it. Sometimes it is lost through over-pasturing and destruction of
turf; but more largely through plowing.

The nut tree is particularly effective as a part of a plowless
agriculture which can use the soil permanently where annual crops ruin
it quickly because the plow prepares the land for erosion.

The speed of soil destruction, with its erosion after plowing, is
particularly noticeable with the great American crops, cotton, corn and
tobacco, which require clean cultivation. Many orchards are also
cultivated for the double purpose of keeping down rival plants and
preserving moisture, but we pay high in soil loss for the moisture that
we get by that means on hilly lands. The plow is one of the greatest
enemies of the future. As a matter of fact we have already destroyed
enough land