requirements. A general statement may be made however, to the 

 effect that all conditions being equal, the consumer should select 

 those fertilizers which give the greatest amount of plant food in 

 suitable and available forms for the least money. A study of the 

 tables of analyses should furnish reliable data in making fertilizer 

 selections. The tables show the quality and quantity of the various 

 essential elements of plant good with the possible exception of 

 organic nitrogen. Prescribed methods of analysis do not include a 

 wholly reliable means of determining the availability of organic 

 nitrogen and in all valuations, in case of the mixed goods, it is assum- 

 ed that the organic nitrogen is present in the best forms. 



The high grade fertilizers will, as a general rule, be the most eco- 

 nomical ones to buy and the low grade fertilizers will, ordinarily, be 

 the most expensive ones. In the manufacture of the best goods 

 only high grade raw materials and chemicals can be used as the for- 

 mula has to be made up of compounds whose united composition 

 will furnish the desired qnantity and quality of plant food and whose 

 combined weight must not exceed 2000 pounds. On the other hand, in 

 the manufacture of very low grade fertilizers the necessary compounds 

 to supply the percentage of nitrogen, phosphoric acid and potash which 

 is guaranteed might be supplied in 1200 to 1500 pounds of material of 

 good quality and the remainder, to make up the ton weight, will be 

 a filler of some sort which often times has no fertilizing value what- 

 ever. Besides this, the consumer is obliged to pay freight and cart- 

 age on low valued or worthless material. Many low grade goods 

 contain a high percentage of phosphoric acid. It should be borne in 

 mind that phosphoric acid is the cheapest of the essential elements of 

 plant food and that some of the low grade mixed goods contain 

 an excess of this material. Cheap or low grade fertilizers are some- 

 times made up of crude stock having a comparatively low commer- 

 cial and agricultural value. 



The State laws provide that guarantees shall 



Guarantees. be made as follows : " percentage of nitrogen 



of potash soluble in distilled water and of 



phosphoric acid in available form, soluble in distilled water 



and reverted as well as total phosphoric acid." Most 



manufacturers give a nitrogen guarantee on their nitrogenous 



