FOOD FOR PLANTS 127 



element releases unavailable Potassium, which in a 

 balanced soil insures the fruit of a fine texture, a thin 

 skin and sweet flavor. 



The Nitrogen in Nitrate of Soda is in a plant food 

 form, which permits the application of Nitrogen at 

 the time the plant requires the food. There is no 

 danger of the Nitrogen becoming available at too late 

 a date, which will cause delay in maturity, a forced 

 growth, with a resultant poor quality and sour fruit. 



Nitrate of Lime. 



When used with superphosphate especially, this 

 combination is not as good a balance as Nitrate of 

 Soda, as there will be an unbalance between bases. 

 In certain cases calcium is very essential, but can be 

 supplied to the soil in the form of calcium carbonate 

 much more economically and effectively. The cal- 

 cium, of which there is 105 pounds to each 400 pounds 

 of nitrate of lime, is in a soluble form. Calcium or 

 lime does not release potash from the soil, therefore 

 potash must be added, as it is an essential plant food. 

 The crop recovery of Nitrogen is the same from 

 nitrate of lime as from Nitrate of Soda (62 per 

 cent). It will take 515 pounds of nitrate of lime to 

 supply the same amount of Nitrogen contained in 

 400 pounds of Nitrate of Soda. 



Gypsum. 



Gypsum, supplying both calcium and sulphur, and 

 being neutral (neither acid nor base) is generally the 

 cheapest and most logical single soil builder to use 

 when sulphur is required or when there is any trace 

 of black alkali. In cases where the calcium content 



