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 in the United States to support many millions of people; and therefore the tree is the more important because it permits an agriculture that will keep the soil indefinitely, and in permanent production, without plowing.

I have aecidently discovered a better way of conserving moisture than by plowing, and I have found it going on in widely scattered places and in widely different climates.

Primitive peoples in many parts of the world have long since obtained the advantage of cultivation, mainly, increasing the available moisture for the tree or plant, without cultivation of the soil and the loss which follows the washing of cultivated soils. As an example I cite the Indians of Arizona, who have grown corn crops for centuries in a country with but from six to fifteen inches of rain. They do this by planting in little patches at the mouth of a gully where at the time of rain the flood water is led away into furrows and depressions so that it thoroughly soaks the ground in which the corn is planted.

My attention was first called to this practice by observing a good patch of barley in the edge of the Sahara in Southern Tunis, where the gulley flow resulting from a winter rain had spread itself out fan-*like and soaked the triangular alluvial area of sand, which bore a fine crop of barley in the midst of the desert.

For centuries the olive growers of parts of Tunis have led gulley water to the olive trees where it was retained, in areas that resembled a tennis court, with a 12 inch bank of dirt around it and two or three olive trees within this area thus watered by impounding.

A practice somewhat similar to this is shown in F. H. King's classic book on Chinese agriculture, "Farmers of Forty Centuries;" but the most extreme case that has come to my attention is furnished by the Berber tribe of the Matmatas, of Tunis. These people live on the edge of a hilly, limestone plateau, where the rainfall is less than 10 inches and in some years as low as five.

An important part of the food supply of these people is furnished by date and olive trees which they grow in the gulches of their limestone plateau. They built a dry rock dam behind which earth-wash lodges. In this the trees are planted and every rain sends more earth and soaks that which has collected. The plan can certainly not be called an experiment for the people have lived there for centuries. They have olive trees that are several centuries old and I have never seen such fine olive trees, not in California, or the plains of Spain, Portugal, France, Italy, or in Algeria or Tunis, and I have seen a good many olive trees in those countries. The olive tree is usually open, light and feathery. These in the Matmatas gulches are thick and black and rank.

For automatic cultivation and fertilization the plan of these primitive agriculturists is hard to beat. You put up your stone dam, and every time the gulley runs with water your crop is irrigated and fertilized. Can you beat it?

Three Americans of my acquaintance have independently experimented and discovered along similar lines.

The late Freeman Thorpe of Hubert, Minnesota, did it with much enthusiasm. So did the late Dr. Meyer, a friend of J. F. Jones, near Lancaster. He discovered it accidentally. He put a brush dam across a gully. Water stood behind it for days after every rain. The apple tree near it grew much more than the others. That started the Doctor. He began to dig small field reservoirs and collect water near trees and he found that it paid even with the very expensive process of hoe and shovel.

The idea has been modernized and brought to the machine stage which characterizes our present-day agriculture, by Mr. Lawrence Lee, a civil engineer-farmer of Leesburg, Va. Mr. Lee runs a level line across the face of the clay hills, and then with a Martin ditcher scoops out a terrace on this horizontal line. It makes the terrace so that the water will hold and will not run away. Mr. Lee is sure that nine-tenths of the heavy thunder shower runs off of the hills, in normal conditions of non-plowing, and that if he plows, most of the water and much of the soil go off together. He is also sure that the water pockets hold both water and soil.

Rows of apple trees planted below these waterholding terraces thrive without cultivation as well as do other trees across the row with cultivation, but with this difference, ordinary cultivation impoverishes the soil and this enriches it by keeping all mineral and organic matter in the field.

The combination of principles worked out by many primitive peoples and also by Messrs. Thorpe, Meyer and Lee makes it possible for the farmer to arrange his rough land in tree crops so that every rain will water his crops, even though the land may be rough and in sod. If he cannot run horizontal terraces he can dig holes near the trees and lead the water to these holes by two furrows with the turning plow. This is really an automatic kind of irrigation. By this means a farmer can use his odd time whenever he can work the ground, and thus do the cultivation for a whole year or two and at the same time preserve the soil and establish a permanent agriculture.

This gives the hill land the same chance as the level lands to grow fat sods. It offers a very interesting combination of blue grass pasture along with crops of black walnuts, Persian (English) walnuts, pecans, grafted hickories, mulberries (for pigs and chickens), persimmons (for pigs and sheep), oaks (which make more carbohydrate food than corn in many situations), honey locust (which has a bean as rich as bran and good for the same purpose) and many other crop trees that will be available if good brains keep developing the idea.

In this connection it may be pointed out that France exports millions of dollars worth of Persian walnuts and most of them are grown on isolated trees scattered about the fields and along roadsides.

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THE PRESIDENT: We will now adjourn to Sormani's for luncheon and then we will immediately start for Mr. Bixby's place on Long Island.

(Adjournment).