Crops and Methods for Soil Improvement

by Alva Agee

CHAPTER XIII

CARE OF STABLE MANURE

Common Source of Losses.—When we bear in mind that four fifths of all the fertility removed from the land in the grains and coarse stuffs fed on the farm may be recovered from the animals and returned to the soil, we can appreciate the consideration that the care of manure should have on every farm. The careless methods that prevail in most sections of the country are an inheritance from the day when soils were new and full of fertility. These methods continue partly through a lack of confidence in the statements that the liquid portion of animal excrements, in average mixed stable manure, has nearly as great value as the solid portion. If this fact were accepted, many of the losses would be stopped. Another reason for continuance of careless methods is failure to appreciate that the soluble portion of manure is the highly valuable part, and that leaching in the barnyard carries away value more rapidly than decrease in volume of manure indicates. The widely demonstrated facts do not have effective acceptance, and enormous loss continues.

Thorne found that manure placed in flat piles in the barnyard in January, and allowed to lie until April, lost one third of its value. Under the conditions prevailing on many farms the loss suffered by exposure of manure is far greater.

Concrete stable floors.

Caring for Liquid Manure.—If all manure were in solids, one great difficulty in caring for it would not exist. The nitrogen is the most valuable element in manure, and two fifths of all of it in horse manure is found in the liquid. In the case of cow manure, over one half of the nitrogen is found in the liquid. More than this, a pound of nitrogen in the liquid has greater value than a pound in the solid because of its nearly immediate availability. There is only one good way of caring for the liquids, and that is by use of absorbents on tight floors or in tight gutters. American farmers find cisterns and similar devices nuisances. The first consideration is to make the floor water-tight, and clay will not do this. The virtues of puddled clay have had many advocates, but examination of clay floors after use will show that valuable constituents of the manure have been escaping. The soils of the country cannot afford the loss, and careful farm management requires acceptance of the truth that a tight floor is as necessary to the stable as to the granary. The difficulty in supplying a sufficient amount of absorbents on tight floors only emphasizes the loss where floors are not water-tight.

Use of Preservatives.—The use of land-plaster in stables helps to prevent loss of the nitrogen-content through fermentation. Its value does not lie chiefly in physical action as an absorbent, but the beneficial results come through chemical action. The volatile part of the manure is changed into a more stable form. In recent years this preservative has fallen somewhat into disuse, as acid phosphate contains like material and also supplies phosphoric acid to the manure. The phosphoric acid content of stable manure is too low for all soils, and the reënforcement by means of acid phosphate would be good practice even if there were no preservative effect. The use of fifty pounds of acid phosphate to each ton of manure will assist materially in preserving the nitrogen, and the gain in phosphoric acid will repay all the cost. It should be used daily on the moist manure, as made in the stable, and preferably just before bedding is added, so that the phosphate will not come into direct contact with the feet of the animals. Some stockmen prefer the use of acid phosphate and kainit mixed half-and-half. The latter is a carrier of potash, and is a preservative of nitrogen.

The use of ground rock-phosphate in stables is coming into use in some localities, chiefly through the recommendation that it be mixed with manure to secure availability of its own plant-food. It is not a preservative except in so far as it acts physically as an absorbent. It should not displace acid phosphate in stables, the preservation of nitrogen in the manure being the vital matter.

Spreading as Made.—When farm conditions make it feasible to draw and spread manure fast as made, the danger of heavy loss in storing is escaped. There is evidence that no appreciable escape of fertility occurs when manure is spread on land that is not covered with ice. The phosphoric acid and potash are minerals, and leach into the soil. The nitrogen does not change into a gas in any appreciable amount when spread over the surface, and it likewise leaches into the soil. There are soils in which the decay of the organic matter would have a more beneficial effect than the rotting upon the surface, it may be, but the mulching effect of the manure is valuable. There should be no doubt that the loss from manure is kept to a minimum when it goes directly to the soil. In some latitudes the snow and ice oftentimes prevent spreading, or make it inadvisable, and in many farm schemes it is desirable to hold manure for special fields and crops. Some means of storing manure must be provided in these instances.