3HAP. ii. NITRATE OF SODA. 1015 



bone, or dissolved guano ; in the latter, of basic cinder, bone-meal, or 

 phosphatic Peruvian guano. 



NITRATE OF SODA. This is the most important, in a sense, of all 

 the nitrogenous artificial manures, because its nitrogen is already in 

 the form in which it is immediately available as plant-food, without 

 having to pass through any intermediate process of chemical change or 

 decomposition. It is a natural salt found in the earth in Chili and 

 Peru, and is purified by washing out and recrystallisation. It contains, 

 in its state of ordinary commercial purity, about 95 per cent, or rather 

 more of real nitrate of soda, equal to about 15 per cent, of nitrogen or 

 19 per cent, of ammonia. 



Formerly much prejudice existed against nitrate of soda, which is 

 really one of the most useful, and now one of the cheapest, manures at the 

 farmer's disposal. It used once to be cried down as a mere stimulant, 

 a manure which acted on the crop merely as a whip, but did not feed 

 it. No more erroneous idea has ever been propagated, and yet it still 

 lingers in the minds of many. Nitrate of soda supplies plant food of 

 the most concentrated and direct kind, and its action is wholly a 

 feeding, and not a stimulating one. It is true that it contains but 

 one essential element of plant food, viz., nitrogen, and therefore it 

 cannot be expected to do alone the work of nourishing a crop, that 

 requires also mineral foods, any more than starch alone would nourish 

 an animal. For nitrate of soda to produce its proper effects either the 

 soil must be in good condition, maintained by the plentiful use of 

 dung, or other artificials must be supplied to supplement it. Without 

 these conditions it will not produce a healthy increase. 



Nitrate of soda is often said to be unduly exhaustive of the soil. 

 There is no doubt that the continued free use of heavy dressings of 

 nitrate of soda alone might leave land in a temporarily poor condition 

 for the next season or two. Such a proceeding, however, may be 

 dismissed as a rare and unlikely one. Self interest would prevent it 

 except in the case of an out-going tenant, and under our present laws 

 which provide compensation for unexhausted tenant outlay, the tempta- 

 tion to such a course is not great. We believe that no sitting tenant 

 would or could, in practical farming, use nitrate of soda in such a way as 

 to permanently injure the land an opinion on which we wish to lay 

 stress, because some landowners, who are not adequately instructed in the 

 question, entertain a strong feeling of animosity towards nitrate of soda, 

 and discourage its use amongst their tenants, lest by its lavish employ- 

 ment, their estates be permanently impoverished. To show how 

 shallow, sometimes, is the knowledge that lies behind this prejudice, 

 we have heard of a landowner who resented the use, by his tenants, of 

 nitrate of soda, but encouraged them to use sulphate of ammonia. 

 The one he regarded as a stimulant, the other as a food. As a matter 

 of fact, there is no essential difference in the action of those two 

 manures, except that one acts much more rapidly in dry weather than 

 does the other. Sulphate of ammonia is turned into nitrate in the 



