116 BOARD OF AGRICULTURE. [Pub. Doc. 



organic and mineral, but always liable to changes Avliich may 

 cause its escape into the atmosphere or its loss through the 

 drainage into the streams and rivers. It is, therefore, im- 

 portant that we should know its origin, its various trans- 

 formations and its comparative usefulness as an element of 

 manures. 



We all know that nitrogen may be obtained for fertilizer 

 purposes in two distinct classes of compounds: first, those 

 which are soluble in water; and second, those which are 

 insoluble. The soluble compounds of nitrogen are those 

 which naturally become more quickly available to plants than 

 do the insoluble. In fact, in the soluble forms we have nitro- 

 gen in the form of nitrates, of ammonia, and, in combination 

 with other materials, as lime in the newer product, cyanamid 

 and lime-nitrate. These, whether nitrate or ammonia, are 

 readily soluble in water, and freely distribute themselves 

 throughout the soil, and, with the exception of nitrate, form 

 fixed compounds which are not liable to be lost by leaching 

 in case of heavy rains, and which are not generally likely to 

 be lost in the atmosphere, unless the soil is wet and compact, 

 or is exceedingly rich in lime. 



Of these three forms of nitrogen, nitrate is the most im- 

 portant, because it is the form in which plants take up the 

 most of this element. In other words, it is the form to which 

 all other forms must be converted before plants can take it 

 up ; the nitrate form is, therefore, quickly available to plants, 

 being absorbed by them immediately it comes in contact with 

 their roots, and is especially useful, therefore, as top-dress- 

 ings for meadow lands, for grain crops, for hay crops, for 

 market-garden crops and for all quick-growing crops, whose 

 chief use is the edible portion of the leaf or stem. 



Of the ammonia forms, we have as the chief source of 

 supply sulphate of ammonia, which, because of its solubility, 

 is almost as quickly available as the nitrate. It distributes 

 readily in the soil, is fixed, and then quickly changes to a 

 nitrate form, and is useful practically along the same lines 

 as nitrate, except its continuous application in large quan- 

 tities has a tendency to cause acidity of soils. In wet seasons 



