Crops and Methods for Soil Improvement

by Alva Agee

THE USE OF STABLE MANURE

Controlling Factors.—The farm supply of stable manure is a carrier of plant-food, returning to the soil four fifths of all the fertility removed in the crops fed, but it is much more than this. Land which receives only plant-food, as may be the case when fertility is supplied in commercial fertilizers, loses good physical condition. Organic matter is needed for maintenance of physical condition, the retention of soil moisture, the freeing of inert minerals in the land, and the promotion of bacterial life in the soil. No small share of the value of a ton of manure is due to its organic matter. This is a factor in the problem when deciding what disposition of the manure will pay best. One field may be in condition to respond fully to the use of commercial fertilizers, while another is too deficient in humus for best results. Some crops are more insistent upon supplies of organic matter than others.

Again, the disposition of the manure depends upon the supply. If most crops are fed on the farm, the manure is a leading source of fertility for all fields and crops, and may be used once or twice in the crop-rotation on every field. If the manure is in small amount, due to a scheme of farming involving the growing of crops for market, the function of the manure may be only to encourage the starting of sods, in which legumes are a leading factor.

Direct Use for Corn.—The practice of spreading manure on grass land for corn is based upon much good experience. The custom is nearly universal in regions where corn is an important part of a four, five, or six years' rotation, and all of the corn and hay is fed on the farm. This disposition of the manure permits the handling at times when other work does not rush. The supply carried over from the spring is put on in late summer, and the manure made in the early part of the winter can be drawn to the field fast as made. Manure spread immediately before the sod is broken is less effective, as no leaching of soluble elements into the surface soil occurs before the coarse material is buried in the bottom of the furrow.

Corn in the Ohio Valley.

The use of fresh manures for corn is rational, because corn is a gross feeder and requires much nitrogen. All plants having heavy foliage can use nitrogen in large amounts. It is possible to apply manure in excessive amount for this cereal, the growth of stalk becoming out of proportion to the ear, but the instances are relatively few. Ordinarily corn suffers from lack of nitrogen. When the farm manure is in large amount, its direct use for corn is good practice.

Effect upon Moisture.—Coarse manures should not be plowed down late in the spring, as they increase the ill effects of drouth. Decayed vegetation, well mixed with the soil, increases the soil's water-holding capacity, but undecayed material in the bottom of the furrow is harmful. Fresh, strawy manure, made immediately before the time for breaking a sod, is preferably carried over in a covered shed until a later season of the year.

When manure has been spread upon a sod in the fall or early winter, it decays quickly after the plowing, and aids in resistance to drouth. When it is plowed down, the ground is kept more porous, and the presence of plant-food and moisture at or near the depth of plowing encourages deeper rooting of plants, and thus indirectly assists them to withstand dry weather. If the plowing is good in character, leaving the furrow-slice partly on edge, and permitting the harrow to mix part of the turf and the manure with the remainder of the soil, the best conditions respecting moisture are secured.

Manure on Grass.—When the crop-rotation embraces two or more years of grass, or one of clover followed by only one of grass, it is better practice to use the manure to thicken the sod. The object in view is the largest possible amount of crops, and the maximum amount of organic matter for the soil. Grass is a heavy feeder, like corn, and makes good use of nitrogen. Its roots fill the soil so that no loss attends the use of manure. When the supply is given the grass, after the harvest of the second crop of clover and during the winter, the timothy can make a rank growth. The part of the plant above ground has corresponding development below ground. Not only does a large increase in the hay crop result, but the heavy mass of grass roots, the aftermath, and the remains of the manure provide a great amount of fertility for the corn which follows. The increase in hay permits a corresponding increase in the manure supply the next year, if it is fed, and if it is sold on account of a market price greater than its value for feed and manure, it adds to income materially—and that is one reason for farming.