86 BOARD OF AGRICULTURE. 



alone, but in one of two forms of combination, — either as am- 

 monia or nitric acid ; and further, the acid must be in associa- 

 tion with an alkali, as soda or potash, in order to be safely 

 employed by the farmer. In either one of these forms it is of 

 immense value as plant food. Nitrogen is a gaseous body, and 

 has neither taste, color nor smell. It cannot be burned, it 

 will not support combustion, and it cannot be breathed into the 

 lungs. It is a strange, negative element, and yet without its 

 influence not a stalk of corn nor a blade of wheat can grow. 

 It is the most costly of all our fertilizing agents, and yet millions 

 and billions of tons are present in the air constantly, and every 

 plant is surrounded by and immersed in it. Is not this state- 

 ment perplexing or paradoxical ? Nitrogen as it exists in 

 nitrogenous bodies is alone available for plants, and the cheapest 

 source, outside of refuse animal compounds, is in the form of 

 nitrate of soda. This salt, known as Chilian saltpetre, is sold 

 at the present time at about four cents per pound, which makes 

 the nitrogen it contains cost about twenty-eight cents per pound. 

 The nitrogen in sulphate of ammonia, at present market rates, 

 costs thirty-five cents, and I have not found it so readily availa- 

 ble or prompt in its action upon my fields. For grass lands, as 

 a top-dressing, the nitrate of soda has proved with me a profitable 

 agent. It brings in the better quality of grasses and largely 

 increases the crops. It should be pulverized fine, mixed with 

 an equal quantity of fine, seasoned peat, and sown evenly over 

 the field, giving to each acre two or three hundred pounds of 

 the salt. Without a supply of nitrogenous food plants become 

 feeble and ultimately die ; and hence we must supply it in some 

 form, either as it exists in manure or in commercial substances. 

 The soil does not furnish it in sufficient abundance, neither does 

 the atmosphere in any available form. There is always a little 

 ammonia in moist air, which comes from decaying animal or 

 vegetable matter, and also there are traces of nitric and nitrous 

 acids in rain-water, but these sources of supply are wholly in- 

 adequate to the wants of plants upon most fields. 



An acre of wheat yielding twenty-five bushels requires, in 

 straw and grain, forty-five pounds of ammonia. The results 

 of careful experiments show that under the most favorable 

 circumstances no more than ten pounds of ammonia is ever 

 supplied to an acre of soil by rain- water ; so if all the ammonia of 



