The upper picture shows well-grown apple trees in good loam soil. The lower picture poor apple trees in light gravel loam. About 40 years is the age of the trees in Both cases

provided these stiff soils have been well aerated by tillage tools, for a time sufficient to put the soil in good physical condition. The best types of wheat land carry less moisture-from 12 to 15 per cent.-than the best grass

types.

Many secondary types are found.-While the mechanical analysis of soils recognizes but eight divisions, classified from the size of soil grains, the direct application to the field will show a great many more factors, since other considerations are in effect here, as the humus content, the arrangement of soil grains, the lay of the land, the ancestry of the soil, and the climatic help or hurt.

The force of this is shown where humus is added to a soil. You find two soils alike in every way. Add humus to one-the texture is changed, the water-holding capacity is increased, the productivity is made greater. You have not changed the size of the soil grains, the basal principle of type remains the same.

Another example: Take two sand soils, of the same basal type precisely, the components in both instances being the same. One is located in a section where the rainfall is abundant and where it is frequent. The other soil in a section where just the opposite extremes exist. It follows, without discussion, that other conditions being present-food, warmth, seed, and culture-the moist soil will generally produce a satisfactory crop and the dry soil an unremunerative crop.

Mechanical analysis a help and guide. We receive assistance when we know soil types, for we have a most helpful guide here at hand. But we have no positive rule to follow in the selection of crops we shall grow. With more study, with more investigation, we may in future years predict with greater safety the behavior of

soil under cultivation and when given certain crops that seem to fancy these special types best.

Bear these things in mind:

I. That sand areas, when properly reënforced with humus, water, and plant food, are peculiarly adapted to all kinds of truck crops.

2. That early truck crops are more safely produced when a maximum of sand and a minimum quantity of clay prevail.

3. That general or late truck crops are most safely produced when the sand type carries the minimum of the coarser and the maximum of the finer sand grades.

4. That fruit growing calls for considerable clay as a part of the sand type.

5. That the best corn crops are produced where neither sand nor clay predominates-the silt materials producing the best results.

6. That the general grain crops are best suited when furnished a silt type of soil.

7. That wheat is most at home in soils where fine silt and clay predominate.

8. That grass fancies most those soils that carry a high percentage of clay.

9. That potatoes prefer a sand type where medium sand prevails, where silt is present in a medium quantity, and where clay is present only in moderate quantities.

10. That with these special types must be included good tillage, humus, air, moisture, and plant food.

Soil type standards.—It is out of the range of possibilities to give definite standards of soil type for specific crops: too many conditions prevail, such as previous treatment of the land, climate, plant food, humus content, soil drainage, tillage methods, etc. The following standards are suggested in the light of known conditions—in a very general way:

1. Early truck and potatoes:

Not more than 15 per cent. of water.
As much as 60 per cent. of medium sand.
Not more than 10 per cent. of clay.
About 20 per cent. of silt.

2. Late truck and fruit:

Not more than 20 per cent. of water.

As much as 50 per cent. of medium and fine sand.
Not more than 25 per cent. of clay.

From 10 to 30 per cent. of silt.

3. Corn:

An average of 20 per cent. of water.

Not more than 50 per cent. of medium fine and very fine

sand.

Not more than 20 per cent. of clay.

From 15 to 25 per cent. of silt.

4. General grain:

About 20 per cent. of water.

From 40 to 60 per cent. of silt.

From 20 to 30 per cent. of fine sand.
From 15 to 20 per cent. of clay.

5. Wheat:

From 15 to 20 per cent. of water.
From 20 to 30 per cent. of clay.
From 30 to 70 per cent. of fine silt.
Not more than 15 per cent. of sand.

6. Grass:

From 20 to 25 per cent. of water.
From 40 to 70 per cent. of clay.
From 20 to 30 per cent. of silt and fine silt.

Not more than 10 per cent. of sand.