30 MANURES 



Though opinions regarding its fertilising action are divided, its use 

 is often attended with much success. It may be applied at the 

 rate of 3 to 5 cwt. per acre or about 3 oz. per square yard, and is 

 found to produce the best results when used in wet weather. It is 

 considered best adapted to light sandy soils, though it is also 

 sometimes successfully employed on heavy clays. 



Ashes. Wood-ashes contain potash and soda, besides other 

 inorganic elements of plant-food, and therefore form a valuable 

 manure. They are suitable for applying by themselves, or for 

 intermixing with dung or other manures. The charcoal which 

 the ashes usually contain in small pieces has the important property 

 of absorbing ammonia and other gases, and again giving them off 

 for the nourishment of plants. Wood-ashes are on this account 

 valuable as a deodoriser. Coal-ashes have useful manurial effects 

 in some cases, especially on stiff clayey soils, owing to the sulphate of 

 lime or gypsum they contain, and have been found to encourage the 

 growth of leguminous vegetables. (See Peat, under Soils). 



Magnesia is essential to the growth of plants, it being always 

 present in their ashes in variable proportions. Applied as a manure, 

 it is considered that it may act directly by serving as food for the 

 plant, or indirectly by uniting with insoluble mineral substances, 

 and rendering these available as plant-food. "Japanese experts 

 show that the ratio of lime to magnesia in soils has an important 

 bearing on many, crops." '(BAMBER). 



Ammonia. Ammonia is one of the most important compo- 

 nents of manures, and one which has a powerful stimulating action 

 on the growth of plants, usually producing a luxuriance of dark 

 green foliage. It is formed by the decay of organic matter in the 

 soil, and also in the air, and is the source from which plants derive 

 their nitrogen. Ammonia is supplied to plants by the decomposi- 

 tion of organic manures capable of forming it, or by the use of 

 some of the salts of ammonia. Of the latter the most commonly 

 employed is 



Sulphate of ammonia. For garden crops or pot-plants this 

 may be dissolved in water (^ ounce to 1 gallon of water) and 

 applied as a liquid manure, having in this way most beneficial 

 effects on plant growth. BAMBER recommends it as u a very useful 

 ingredient in mixtures, as it supplies soluble nitrogen in a most 

 concentrated form ; the quantity so employed may be from 25 to 

 50 Ibs. or more per acre." This and other salts of ammonia are 

 very powerful in their action, and need to be used with caution. 



