6 The Bulletin 



Water-soluble Ammonia. — The main materials furnishing ammonia 

 in fertilizers are nitrate of soda, sulphate of ammonia, cotton-seed meal, 

 dried blood, tankage, and fish scrap. The first two of these (nitrate of 

 soda and sulphate of ammonia) are easily soluble in water and become 

 well distributed in the soil where plant roots can get at them. They are, 

 especially the nitrate of soda, ready to be taken up by plants, and are 

 therefore quick-acting forms of ammonia. It is mainly the ammonia 

 from nitrate of soda and sulphate of ammonia that will be designated 

 under the heading of water-soluble ammonia. 



Organic Ammonia. — The ammonia in cotton-seed meal, dried blood, 

 tankage, fish scrap, and so on, is included under this heading. These 

 materials are insoluble in water, and before they can feed plants they 

 must decay and have their ammonia changed, by the aid of the bacteria 

 of the soil, to nitrates, similar to nitrate of soda. 



They are valuable then as plant food in proportion to their content 

 of ammonia, and the rapidity with which they decay in the soil, or 

 rather the rate of decay, will determine the quickness of their action as 

 fertilizers. With short season, quick-growing crops, quickness of action 

 is an important consideration, but with crops occupying the land during 

 the greater portion, or all, of the growing season, it is better to have a 

 fertilizer that will become available more slowly, so as to feed the plant 

 till maturity. Cotton-seed meal and dried blood decompose fairly 

 rapidly, but will last the greater portion, if not all, of the growing season 

 in this State. While cotton seed and tankage will last longer than meal 

 and blood, none of these act so quickly, or give out so soon, as nitrate of 

 soda and sulphate of ammonia. 



Total ammonia is made up of the water-soluble and organic ; it is the 

 sum of these two. 



The farmer should suit, as far as possible, the kind of ammonia to 

 his different crops, and a study of the forms of ammonia as given in 

 the tables of analyses will help him to do this. 



AVAILABILITY OF NITROGEN 



During the past few years the increasing cost and the extensive use 

 for other purposes of the standard high grade ammoniates have caused 

 the appearance upon the market of many new nitrogenous materials 

 which are being used as sources of nitrogen in commercial fertilizers. 

 These materials are, to a large extent, trade-waste products, in them- 

 selves not permissible as sources of nitrogen, but which after treatment 

 in various ways develop a considerable degree of availability, and in 

 many cases the nitrogen contained therein becomes very largely water- 

 soluble. 



On account of the e.xteiisivo use of tliose now ammoniates this dejiart- 

 nient is now making in its laboratory by chemical methods determina- 

 tions of the availability of the water-insoluble organic nitrogen in the 

 samples of fertilizers taken for analysis. In this way we are largely able 



