112 



ammonia escapes into the atmosphere in stables where absorbents are not used. 

 Should there not be a very good system in cow-houses and pig-pens for conducting the 

 liquid portion of the manure to tanks, a loss of fertilizing elements will be sure to 

 ensue through soakage, unless some material is scattered that will take it up and 

 retain it. For this purpose, the use of dry peat and muck can be with confidence 

 advised. In this connection, it must not be forgotten that while the plant food in 

 manure is thus rendered permanent by such treatment, the fertilizing ingredients of 

 the absorbent are at the same time made more valuable for immediate use. 



MAEL. 



One sample of this natural fertilizer was analysed quantitatively during the 

 past year. It was forwarded by H. Glendinning, Esq., of Manilla, Ont., and upon 

 analysis was found to have the following composition : — 



Moisture 8-57 



Organic and volatile matter 3'24 



Clay and sand (insoluble in acid) 2"50 



Oxide of iron and alumina -62 



*Lime 47-22 



Magnesia -74 



Potash, (slight traces) 



^Carbonic acid 37"11 



Phosphoric acid, (traces) 



200-00 



^Cai'bonate of lime 84.33 



Marl owes its fertilizing properties essentially to the carbonate of lime it 

 possesses. This specimen contains 84-33 per cent., showing it to be somewhat above 

 the average. In other plant food — nitrogen, phosphoric acid and potash — as is 

 usually the case, it is not rich, these elements not being present in notable quantities. 



The application of marl is especially to be recommended for heavy clay and for 

 very light soils in which sand and peat predominate. Besides supplying lime — an 

 ingredient of plant food — it renders the tilth of the former mellower, allowing air 

 to permeate the soil and the roots to spread more easily ; ^its addition improves 

 sandy soils, by making them heavier and more retentive of moisture and fertilizing 

 materials. By the slow oxidation of the organic matter of peaty soils it converts 

 their nitrogen into forms which can be taken up as food by plants. This beneficial 

 process is chiefly brought about by a microscopic plant in the soil, known as the 

 ferment of nitrification — to which allusion has been made in the preceding chapter — 

 the development of which is greatly encouraged by an excess of carbonate of lime. 

 To all soils deficient in lime it may advantageously be applied, furnishing thereby 

 not only plant food, but also setting free in the soil the inactive store of materials, 

 so that the}^ may be assimilable by vegetation. Lime in all its forms has been 

 proved of special value as a manure for the leguminosae — of which peas, beans, 

 etc., are important members. 



A good marl for agricultural purposes should be of a light colour, and not of a 

 hard or flinty natui-e. Such will easily disintegrate or break down on exposure to 

 the weather, allowing it to be easily mixed with the soil. 



GYPSUM. 



One of the most valuable of the fertilizers that occur in nature is gypsum, com- 

 monly known as land plaster. It is the result of the union of sulphuric acid and lime, 

 both elements of plant food. Thus it is that plaster supplies nourishment directly 

 to the growing crop. It, however, also acts beneficially — and perhaps principally — 



