32 



The reason for giving preference to peat moss and the three fol- 

 lowing materials is because they possess the first quality in the 

 highest degree. This will be considered further under the head of 

 " How to make barnyard manure." But when cleanliness is con- 

 sidered the straws rank first, and peat, muck and loam come last. 

 Sawdust and leaves decompose very slowly, and leaves especially 

 have but little nitrogen, potash or phosphoric acid left in them. 

 Unfortunately, all the good qualities are not possessed by any one 

 material. Peat, etc., have the highest conservative power, but 

 they are not cleanly. The clean straws, however, are the poorest 

 in conservative power, because they support the bacteria which do 

 harm. (See " How to make barnyard manure.") 



Although high percentages of nitrogen, potash and phosphoric 

 acid are valuable in litter, the best of these materials contain only 

 small amounts, and this quality is outranked by those placed be- 

 fore it in the above list in giving value to barnyard manure. 



"Fixers." — When manure is stored at any depth over a few 

 inches, it ferments, and large quantities of the most valuable 

 nitrogen become soluble and volatile in the form of ammonia, 

 which is a gas. This gas is well known as "hartshorn," and is 

 easily recognized by its strong odor. It forms very rapidly in the 

 presence of a limited amount of moisture and a somewhat ele- 

 vated temperature. Urine is its principal source, and next to that 

 comes horse dung. 



It is very important that all this gaseous form of nitrogen be 

 saved, and whenever its odor is detected, means should immedi- 

 ately be taken to " fix " or absorb it. No space containing manure 

 should be allowed to smell of ammonia. Substances used for this 

 purpose are : — 



Hydrochloric acid, which fumes strongly. 



Sulphuric acid, which does not fume, but corrodes everything 

 it touches, e. g., the hoofs of horses and cattle. 



Neither of the above should be employed. 



Green copperas is good, but it is also slightly corrosive, and 

 often injux-ious to crops. 



Gypsum or land plaster is excellent. 



Sulfate of magnesia is the same. It sometimes combines with 

 and holds the soluble phosphoric acid. 



These materials are sprinkled daily over the floor and manure. 



Preservatives. — While the foregoing substances retain the am- 

 monia, they do not prevent fermentation. Sometimes a farmer 

 wishes to accomplish both of these ends. The following sub- 

 stances, when mixed with the manure, act in this double way : — 



Sulfate of magnesia, or kieserite. 



