Division of Agriculture. 



William P. Brooks. 



SOIL TESTS WITH FERTILIZERS. 



During the season of 1890 Soil Tests with Fertilizers have been 

 carried out under my supervision in the counties of Essex, Middlesex, 

 Plymouth, Bristol, Barnstable, Worcester, Hampshire, Hampden, 

 Franklin and Berkshire. Besides these we have had two acres in a 

 similar experiment with corn upon our own grounds and several vol- 

 unteer workers in different sections of the state. In the following 

 pages will be found an account of the experiments in the several 

 counties above named as well as of those on our own grounds and of 

 one by a volunteer worker whose crop was more or less directly under 

 our eyes during growth and which was weighed at harvest by my 

 assistant. 



The plan of exi)eriment was similar to that followed in 1889 and it 

 is described in detail in Bulletin No. 9 of this Station. One acre 

 was used in each experiment and the crop was corn. In each acre 

 were laid out fifteen plots (with one exception where there were four- 

 teen) of one-twentieth of an acre each : and the fertilizers used were 

 nitrate of soda, dissolved 'bone-black, muriate of potash, land plaster, 

 lime and barn-yard manure. The first three mentioned fertilizers were 

 selected as sources respectively of nitrogen, phosphoric acid imd pot- 

 ash which are recognized to be essential elements of all fertilizers and 

 manures, — often indeed they appear to be the only essential elements. 

 The reason for selecting these materials is that they allow us to fur- 

 nish essentials of plant food singly or in any desired combination. 

 Other materials might serve the farmer's purpose equally well ; but 

 for our purpose we must have forms of fertilizers which enable us to 

 trace results to definite causes. 



