neighbors, to be in turn robbed by the neighbor next below. In this way surface tension aids gravity in removing the water from the surface into the soil, and much more rapidly than where the soil in the same mechanical condition is free from moisture. It is the difference between the rate at which the first rain drop trickles down the dry glass, and the next one that follows in the moistened track. For this reason a moist soil gets much more of a shower that gives less than an inch of rain than does a dry soil, because it moves a much higher precentage of it away from the influence of the sun and wind.

HOW THE WATER IS LOST.

This will also explain how the water is so easily lost from the soil by evaporation. When the surplus rainwater is removed and drainage has ceased, then the operation is reversed. The sun, wind and dry air promptly attack the water films on the surface soil grains, reducing their thickness. The surface films give to the air, and take from the films below to make good the loss. In a short time there is a continuous stream from a depth of possibly two feet to the surface to make good the continual loss at that point. This upward movement is most rapid when the films are thickest and most elastic, and grows less as the films grow thinner, and are held with greater force against the soil surface. The manner in which this loss occurs suggests the remedy or preventive. Change the moisture. line from the surface of the ground to a point two inches or more below the surface. Do this by stirring the top soil so as to loosen and dry it out. This enlarges the capillary spaces and breaks the films. Water cannot rise from a half-saturated soil into a dry soil. Two and two and a half inches of dry soil is a very effective mulch, as good as dry straw, but needs renewing after every shower. Keep the surface soil dry. This is the lid to the soil cistern, and the stopper to the soil water bottle.

LOSSES BY EVAPORATION.

During June, July and August, the greatest loss of water from the soil is by evaporation during the first four days after the rain has ceased falling. The run-off water and that carried off by subsurface drainage may seem larger to us, because we can see it, but it is insignificant as compared with the amount of water absorbed by the air. After the fourth dry day the surface of the unshaded soil will have crusted or dried out sufficiently to greatly reduce the upward flow of water, and the interlacing roots will intercept what is left. It is immediately after the shower ceases that the heaviest loss occurs, and it is the promptness with which we stir the exposed soil after heavy showers, or the amount of humus in the soil to enable it to dry out on the surface without crusting or baking, that determines how much of the rainfall we lose, or how much we save for use by the growing crops.

TILLAGE.

We plow, harrow, roll and cultivate that we may separate the particles that have been compacted by the frequent rains during the

year, and rearrange them loosely, but with as many points of contact as possible, just like meal in a barrel. Cavities are waste places in the soil, and should be removed by cultivator, disc or roller. If we arrange oranges in a box, placing each one on top of the other, each with four points of contact, they will occupy 52 per cent. of the space. But if we slip them in between one another, in alternate rows, we have six points of contact for each orange, and gain over 10 per cent. of space in the box. (See Figures 5 and 6).

The more uniform the soil grains can be arranged, giving most points of contact, the more water can be held back from drainage and stored in the tiled soil for the use of the plants. The greater the depth of tillage, the greater the water supply near the root zone, but the land should not be plowed deeper than it can be thoroughly worked, and should be deepened by degrees, making no marked change in any one year. It will take about two inches of dry soil earth to form a satisfactory dry earth mulch to protect the soil moisture on the mountain farms, and two and one-half inches for the lowlands and the southern part of the State. If the land is plowed six inches deep there only remains three and one-half inches of stirred soil in which the finer roots can develop and grow. If the land is plowed eight inches, then the root zone is increased to five and one-half inches, or an increase of 36 per cent. of new feeding ground for the plant roots. This is just like taking a ten-acre pasture that will carry seven cows, and by fertilizing it, making it produce enough more grass to carry ten cows equally well. It is another way of increasing the size of the farm by adding two inches to the bottom instead of buying 36 per cent. more, land to add to the side, and putting the same amount of labor one one hundred acres that would be put on the one hundred and thirty-six acres.

The study of this question suggests that in the preparation of the seed bed, the finest soil should be worked into the lower half of the depth stirred, where the roots grow thickest, and the coarse soil, clods and trash should be worked to the surface to break the force of the heavy rain drops, and partially prevent packing and puddling of the surface soil. This suggests further the fining of the surface soil with disc or harrow before plowing and turning this fined soil into the bottom of the furrow. After plowing, the tool used should pack the under surface to remove the cavities left by the plow. It should press downward. The roller may be used to break clods, but never to finish with. Rolled land should be harrowed at once to sift the fine soil down and lift the coarse soil up. A spring tooth is good for this.

The objects of tillage are: First, to increase the water-holding power of the soil, so that more will run in and less will run off or drain out. Second, to admit air freely to all parts of the soil, that the bacteria of the soil may develop and thrive, and carry on the work of tearing down the organic matter, and prepare it for food for the plant, and to facilitate the dissolving of the mineral elements. Third, to make it easier for the fibrous rootlets to thread their way through the soil and get in contact with the water films in which the food is held in solution. Fourth, to prevent growth of weeds and loss of moisture after heavy rains by prompt tillage, two to two and a half inches deep.

The poorer a soil is in vegetable matter or humus, the less water it will hold, and the quicker it will lose what it does retain.

The adding of manure, and especially the turning under of catch crops (legumes preferred) will increase the water-holding power, and it will suffer much less loss by evaporation, because the top inch will dry out without crusting or baking, forming a partial dry earth mulch. The richer soil is more drouth resistant, and suffers less from lack of tillage, when prompt tillage cannot be given.

LIMING THE SOIL.

Figure 7 is a reproduction of the clay particles floating in a drop of water, showing how they repel one another and keep separate. Figure 8 shows the same sample, with a little lime water added. Note how the lime acts on the clay particles to draw them together in clusters, so that each little mass acts toward water and air together as one soil grain. This flocculation by the action of lime

gives clay soils a more porous and loamy character, and points out one way in which lime benefits the soil physically, if used in moderation, and in the presence of organic matter.

Figure 9 is another illustration of the flocculating effect of lime on fine soils. Its chemical effect in sweetening sour lands is already well known to the farmers of the State, and it has other chemical effects already published by the State College in official bulletins.

Fig. 9.

DRAINAGE.

The value of tile drains is to remove the surface or gravity water from the surface two or three feet, so that air may freely penetrate where the soil has a tendency to form a ground water level near than three feet to the surface. It has a further use in letting the trapped air escape when the rain falls faster than the films can remove it down into the soil by simply thickening it. When the spaces are water-logged for two or three inches, the trapped air is compressed, and this compressed air hinders the gravity flow into the subsoil, and forces washing at the surface. If, however, there are drain tiles, the compressed air is forced into these, and the water follows, thus relieving the surface clogging and lessening the surface washing.

In presenting this subject, you have discovered that I offer no easier way to get a certain amount of product from the soil. The product is more the result of so much labor, rather than the yield of so many bushels per acre. We need a new way of expressing the results obtained, which should be so many bushels or pounds per unit of energy, intelligently exerted, rather than so much per acre. One of our oldest axioms is still one of our newest, that "Man must earn his bread by the sweat of his brow."

NATURAL AGENCIES IN SOIL IMPROVEMENT.

BY PROF. E. B. VOORHEES, New Jersey Experiment Station, New Brunswick, N. J.

The question of soil fertility is one of the first importance. It measures in large degree the size and quality of the crops that grow. Seasons may change, climates may be different, but in any case fertility is the one thing that more than any other controls the harvest. It is but natural, therefore, with the growing knowlegde that we have of the soil in its various phases, that its study should occupy our minds more completely than any other one subject connected with farming. Other lines of investigation contributory to the uplift of farming have their best application only when fertility is the basis. It is quite natural, too, that until we understand the soil more fully that the methods of practice adopted are

not such as to contribute to the upbuilding of the soil, but rather to its depletion. This has been the history of all countries, and is the history of our country as well. Until within quite recent times, our knowledge of the soil did not permit us to give advice to farmers that would enable them to conserve or build up their fertility, because we did not know surely what was involved, and even now we are but on the threshold of the knowledge that lies before.

As an introduction to my subject, I desire first to present some general considerations concerning what may be termed constructive and destructive natural forces. The natural forces of sun, air, water and temperature, and the principles upon which the science of geology, of chemistry, of botany, of biology, and of physics are based, are all concerned in the proper development of the farm, and the true progress of the farmer, and have existed since the beginning of time. Because these are facts, the methods of farming in vogue from the earliest times to the present, and the methods of today, have exerted, and still exert, an influence upon the development, progress and happiness of all the people upon all the earth.

Since the solid portion of the earth first appeared these forces and others, seen and unseen, known and unknown, have been constantly at work changing the character of its surface. These forces have wrought by day and by night, in summer and in winter, in sunshine and storm, but always and incessantly, and, as a result of their action, there appeared upon the hard and rocky surface, first, the humble lichen, then the more haughty gorse or furze, which, in their way, became forces, too, and assisted these mighty unseen workers, until, in their task of world-building, the former rocky surface of the earth, whether the mountain or valley, whether the prairie or desert of today, became covered with the various forms of vegetable life, each drawing its sustenance from the mineral and organic matters, more or less broken down or decomposed, that we call soil. This soil, which we now work, and which, if left to nature again, would not produce crops that the farmer regards as largely useful, with the possible exception of timber, yet a more detailed study of the action of these natural forces when not directed will, I think, give us some clue as to their value when controlled and directed by human intelligence, wherever there is the purpose to derive from such soil sustenance for man and beast.

The tendency of our cultivated fields, if left to nature's way, would be to cover them with growths of various sorts, and gradually there would be accumulated substances that would provide more favorable conditions for the growth and development of cultivated plants. That is, the continuous occupation of the soil by growing plants would, in the first place, hold the particles of soil together and prevent their movement by mechanical means, and in the second place, the growth of the plants themselves would cause a breaking up of hard and insoluble substances of that soil, making them available to plants, and the organic matter accumulated and mixed with the mineral substance would make the soils more absorptive, and would prevent the rapid washing away of the soluble constituents. Besides, because of its greater absorptive power, floods, drouths and consequent barrenness and sterility would be largely prevented.