356 STATE BOARD OF AGRICULTURE 



fertilizer, but simply states that the manufacturer or dealer offers for sale a 

 fertilizer for which a certain content of nitrogen, potasli and phosphoric acid is 

 claimed, and that samples of such fertilizers have been deposited with the secre- 

 tary of the college with affidavit regarding the composition. Analysis is then 

 made of each of these fertilizers, gathered in the open market as far as possible, 

 and the results of such analysis published in bulletin. The claimed composition 

 and found composition are arranged in parallel lines, so that the real composition 

 can be compared at a glance with the composition claimed for it by the manufact- 

 urer. In this way the buyer can see at once by this bulletin whether the fertilizer 

 is as good as the claims made for it. 



RESULTS REACHED BY INSPECTION. 



The quality of the fertilizers sold in this State has greatly improved within 

 a few years past. On comparing the composition as "claimed" witli that "found" 

 by analysis, it will be seen thar in only a few cases does the minimum claim 

 exceed the amount actually found, and in many cases the amount found exceeds the 

 highest amount claimed. The day when the mixture of leached ashes and soap- 

 boilers' waste can be sold for superphosphate or marl palmed off for Buckeye phos- 

 phate has passed away in Michigan. 



WHAT DO COMMERCIAL FERTILIZERS CONTAIN? 



The first question one asks about a new article is, "What is it made of?" and 

 the second is, "Will a material of such composition and at the stated cost, give 

 me a profit when used on my farm?" 



Commercial fertilizers contain a variety of substances, but only three of such 

 importance that the farmer can afford to buy them at the prices charged for con- 

 centrated manures. They often contain lime, magnesia, silica, oxide of iron, sul- 

 phates, chlorides, etc., many of these of value as manures, but they can be bought 

 for less money than is charged for the commercial fertilizers. The fertilizers 

 may contain all these, but we buy them because they contain in addition one or more 

 of three materials, viz., potash, phosphoric acid, and active nitrogen. It is the 

 presence of these materials that gives commercial value to fertilizers. If the 

 dealer boasts that his manure contains alumina, silica, oxide of iron, lime and 

 magnesia, the sufficient answer is that these materials make up the mass of all 

 soils, and that the farmer buys his land by the acre and not by the ton. The 

 only manurial materials that a farmer can afford to buy at prices demanded for 

 fertilizers are these three most necessary, most precious, and most easily 

 exhausted elements of plant growth — the tripod of agriculture. In the absence of 

 any one of these three materials no plant can grow to perfection, and if the 

 supply of them is below the needs of any given plant, that deficiency limits the crop 

 proportionally. However abundant all the other elements of plant life, nothing will 

 make up for the lack of any one of these three substances. 



LEADING KINDS OP FERTILIZERS. 



The leading kinds of fertilizers may be classified as follows: 



1. Complete manure, which contains nitrogen in some combination, such as a 

 salt of ammonia, nitrate of soda, or organic nitrogen; potash, as muriate or sul- 

 phate (German Stassfurth salts) or wood ashes; and phosphoric acid as a phos- 

 phate of lime. It is called a complete manure because it contains all of the three 

 materials most essential for plant growth, and most likely to be deficient in a 

 field after long cropping. .^ 



2. Plain Phosphate, which may be in the form of superphosphate, soluble in 

 water or solution of citrate of ammonia, these being called available, because 

 they are readily taken up by the roots of plants; and ground phosphate rock, an 

 insoluble form. The bone phosphate and rock phosphate are changed into super- 

 pho.sphate by the action of sulphuric acid, removing a part of the lime, as sul- 

 phate. 



The soluble phosphate is especially beneficial to plants in the early stage of 

 their growth, giving them a good start. In later stages of growth when the plant 

 by its roots can forage for food in the soil, the insoluble phosphate may have 

 nearly as beneficial an effect. 



Phosphates promote the formation of flower and fruit and secure earlier ripen- 



