MANURING 249 



nitrogen from the air by bacteria, living in the soil itself, vegeta- 

 tion would be scant indeed and the animal world, including 

 mankind, could not exist. 



As a matter of fact agriculturists in both Europe and 

 America depend largely for the necessary fertilizers to produce 

 their crops of grain on the nitrogen present in the nitrate de- 

 posits of Chile. When these are exhausted, as they will be in 

 about twenty years, starvation may stare the world in the face 

 unless the large electrical establishments now at work in Nor- 

 way, Germany, Italy and the United States, endeavouring, with 

 some success, to fix free nitrogen from the air, can enormously 

 increase their output. 



One of the most successful companies engaged in this work 

 is the Societa Italiana per la fabbricazione di proditti Azoti, of 

 Rome. They have now put into the market calcium cyana- 

 mide under the name of " kalkstickstoff," a fertilizer rich in 

 nitrogen, and Dr F. Lohnis, of Leipzig, as the result of careful 

 experiments, has been able to show that bacteria alter it and 

 produce at a greatly-increased rate food for plants. 



Briefly, the manures which up to the present have been in 

 demand to supply nitrogen are nitrate of soda, sulphate of 

 ammonia, nitrate of lime and such substances as oil-cake, rape 

 meal and blood meal. To make up deficiencies of phosphorus, 

 superphosphate of lime and basic slag are most in demand, and 

 crushed bones or bone-meal are also used, but are expensive 

 and not so beneficial. Expense also prohibits the frequent 

 use of large quantities of phosphatic or fish guanos. The 

 commonest form of a potash manure is the substance known 

 as Kainit, a natural salt containing approximately 22 per 

 cent, of sulphate of potassium and 2 per cent, of potassium 

 chloride. 



Just a word of warning about chemical fertilizers might be 

 useful. It is this: frequently one element acts very quickly 

 upon another and their usefulness is much impaired when mixed 

 together and not immediately applied to the land. 



The manure from cattle is, of course, of considerable value, 

 but its contents naturally vary according to the fodder upon 

 which the animal has been fed. The liquid portion is the best, 

 being the richest in nitrogenous matter, and should be carefully 

 preserved. If, however, such manure is not produced on the 



