84 



REPORT OF THE CHEMIST OF 



These tables present some interesting results, but in order to see their 

 exact bearing, the rainfall for the season must be considered. 



1889. May 



June 



July 



August 



September 



October 



Rainfall 



at 



Grayling, 



Inches. 



2.85 

 4.05 

 3.5fr 

 1.95 

 .70 

 .72 



From the 1st of August to the 31st of October there were 2.12 inches of 

 rainfall at the College, yet the average percentage of water in the cultivated 

 surface soil was 13.89, just 3 per cent more than similar soil left as naked 

 fallow. From September 27 to October 18, without a drop of rainfall, this 

 cultivated soil increased 2 per cent in moisture without any corresponding 

 change in the layer of soil immediately below it. The raked surface soil 

 had 1 per cent more water than the naked fallow, but 2 per cent less than 

 the cultivated soil. 



In the sands at Grayling the benefit from cultivating does not appear, and 

 only slight benefit from raking. The smaller percentage of water in the 

 grass lands in both stations is marked. These might be expected from the 

 large amount of evaporating surface of the grass plants and the demand for 

 moisture from the soil. The raking of the grass was done to see if harrowing 

 or scratching the surface would tend to keep meadows moist the same as 

 plow-land. No influence of this kind is apparent. 



These experiments on soil moisture as modified by the physical condition 

 of the soil will be repeated and extended another year, and an effort will be 

 made to ascertain the influence of rolling and compacting the surface soil. 



III. — SOIL TEMPERATURE. 



Observations on the temperature of the soil at various depths during the 

 growing season have been made at the College and at Grayling. The soil 

 thermometers were made by Green, of New York, and the temperature was 

 observed thrice daily, at 3, 6, 9, 12 and 24 inches below the surface. The 

 record is given in the following tables, from the 1st of April to the 31st of 

 October for both localities. 



