Manures and Manuring 147 



spirits of salts (hydrochloric acid) will be covered with a white crust of sal 

 ammoniac, produced by the union of the acid with the escaping ammonia. 



Manure should be well packed or trodden down, as it loses ammonia 

 more readily if left in a loose condition, Wonderful chemical changes 

 take place rapidly in the heap, and micro-organisms are at work reducing 

 the organic material into a finer, less littery, and more fertilizing compost. 

 In this way the manure heap loses considerably in bulk, and the farmer 

 and gardener must take care not to let it remain too long before working 

 it into his soil. It has been computed that 100 loads of fresh dung left 

 exposed to the action of the weather loses nearly 27 loads in 81 days, 

 35^ loads in 254 days, 37 loads in 384 days, and about 53 loads (over 

 one-half) in 493 days. 



Growers of flowers, ferns, palms, &c., use stable or farmyard manure 

 in fairly large quantities, but not of course so largely as market gardeners 

 and farmers; and many of them preserve all the ingredients of the manure 

 by stacking it in layers with soil. Thus a bed is marked out, and per- 

 haps a layer of soil 1 ft. thick is spread over it. On top of this a layer 

 of manure 3 or 4 ft. thick is placed. Then another layer of soil, followed 

 with a layer of manure, until the material is used up the top layer always 

 being soil. Arranged in this sandwich-like way, the layers of manure 

 decay evenly, and at the same time fertilize the layers of soil. In due 

 course the compost is chopped down with the spade, and is used in various 

 proportions with other soil for any special crops. While it may not be 

 always possible or convenient for market gardeners to store manure in this 

 way, those who cultivate plants of any kind in pots will find it an excel- 

 lent method of producing a rich and agreeable compost. 



Value of Farmyard Manure. Farmyard manure is a bulky manure, 

 but in a good condition it is probably the best and safest of all manures, 

 natural or artificial. Although 1 ton of it only contains from 9 to 15 Ib. 

 nitrogen, 4 to 9 Ib. phosphates, 9 to 18 Ib. potash, and 39 Ib. carbonate 

 of lime, its fertilizing value must not be judged from these quantities 

 on the unit system applied to artificial manures like sulphate of am- 

 monia or nitrate of soda. While it is in itself a complete manure, con- 

 taining all the foods from the soil, water, and air, it possesses mechanical 

 advantages superior to any other manure. Being bulky, when dug into 

 the soil it pushes the clods asunder and allows fresh air and water to 

 enter freely. By its decomposition or fermentation heat is generated, 

 carbonic acid gas is given off, minerals and metals are rendered soluble in 

 conjunction with lime, and millions of bacteria are brought into being to 

 produce other foods in the soil. These important functions cannot be per- 

 formed or brought about by any chemical manure by itself, and it would 

 be courting disaster to use them exclusively on any soil. 



The quantities of farmyard manure necessary to keep a soil in a fertile 

 condition vary according to the soil and its nature. On loamy soil in a 

 well -cultivated condition from 12 to 16 tons may be regarded as a fair 

 dressing. In a heavy loam, or clayey soil as it is often called, from 16 



