"Four thousand pounds of manure from the horse stable were placed out of doors in a compact pile and left exposed from April 25th to September 22d. The results were as follows:"
----------------------------+-------------+--------------+---------- | April 25. | Sept. 22. | Loss | | | per cent. ----------------------------+-------------+--------------+---------- Gross weight | 4,000 lbs. | 1,730 lbs. | 57 Nitrogen | 19.6 " | 7.79 " | 60 Phos. acid | 14.8 " | 7.79 " | 47 Potash | 36 " | 8.65 " | 76 Value of plant food per ton | $2.30 | $1.06 | ----------------------------+-------------+--------------+----------
This shows a loss of more than half the bulk of the manure and more than half the plant food contained in it.
The first step to be taken in preserving the manure or in checking losses is to provide sufficient bedding or litter in the stable to absorb and save all the liquid parts.
The losses from fermentation of hot manures like horse manure may be largely checked by mixing with the colder manure from the cow stable.
Losses from fermentation may also be checked.
By piling compactly, which keeps the air out.
By moistening the pile, which lowers the temperature and checks the access of oxygen.
The manure may be hauled directly to the field each day and spread on the surface or plowed in. This method is the best when practicable because fermentation of the manure will take place slowly in the soil and the gases produced will be absorbed and retained by the soil.
Gypsum or land plaster is often sprinkled on stable floors and about manure heaps to prevent the loss of ammonia.
Copperas or blue stone, kainite and superphosphate are sometimes used for the same purpose. There is, however, nothing better nor so good for this purpose as dry earth containing a large percentage of humus.
Losses from washing or leaching by rain may be prevented by piling the manure under cover or by hauling it to the field as soon as produced and spreading it on the surface or plowing it under.
From ten to twenty tons per acre is considered a sufficient application of barn manure for most farm crops. Larger amounts are sometimes applied to the soil for truck and market garden crops.
Barn manures are applied to the soil by these methods: