MANURES 51 



Nitrate of soda (Chili saltpetre). Of nil the nitrogenous 

 manures, nitrates are the most rapid in action, as the nitrogen they 

 contain is actually in a condition in which the plant am take it up 

 at once without change. Being readily soluble in water, it is easily 

 washed out of the soil by rain or heavy artificial waterings ; it 

 should therefore be applied rather in a dry season and when the 

 plants are well-established and in active growth. Nitrate of soda 

 is obtained from Chili, and is sometimes called Chili saltpetre. 

 Owing to its high percentage of nitrogen (about 15#), it has very 

 stimulating effects as a manure, and should be used in small dress- 

 ings occasionally, rather than in one heavy application. It is 

 readily assimilated by plants, and is considered especially suited 

 for root and grain crops. For garden crops an application of about 

 1 Ib. per 40 square yards, or 1 cwt. per acre, applied as a surface 

 dressing, is considered a sound practice. It is computed that 3 cwt. 

 of nitrate of soda is equal in value as a fertiliser to 80 tons of 

 farm-yard manure. 



Calcium nitrate is manufactured in Norway, and is obtained 

 by extreme heat, achieved by means of the electric arc flame, 

 under which atmospheric nitrogen is made to directly combine with 

 oxygen. The chemical combination produces nitric acid gas. 

 The compound is afterwards passed through water and lime, and 

 finally a solid nitrate of lime (calcium nitrate) is obtained. 



Potash is found in large quantities in the ash of plants, and 

 is a valuable constituent of manures. It is of special value to 

 starch and sugar producing crops, as potatoes, beet, etc., as also 

 to fruit crops, constituting as it does the principal ingredient in the 

 ash of fruits. Potash is of special importance in the process of 

 assimilation, in which starch is converted into sugar. It is rarely 

 used as a manure by itself, being usually applied in conjunction 

 with nitrogenous or phosphatic fertilisers. Soils which are sandy 

 or gravelly, or have become exhausted from continuous cropping 

 or from lack of manuring, stand most in need of this form of 

 manure. The chief source of potash salts, of various grades, lies 

 in the saline deposits at Strassfurth and other places in Germany. 



Nitrate of Potash (sometimes called Xilrc, or Stillpclrc) is a 

 combination of potash and nitric acid. It is a powerful manure, 

 containing both -nitrogen and potash, and is especially adapted for 

 fruit production. The frequent use of this is, however, considered 

 to have the effect -of exhausting soils of organic matter. It is 

 recommended for forking in among Tea plants at the rate of about 

 100 Ib. per acre. 



