190 



STATE BOARD OF AGRICULTURE 



No crop- 

 Clover... 



1st foot. 



Per cent. 

 9.30 

 9.89 



.59 



2nd foot. 



Per cent. 

 7.59 

 2.75 



4.84 



Average 

 three feet. 



Per cent. 



8.15 

 5.10 



3.05 



There was 62.5 per cent more moisture in the soil of the plot that had borne no 

 crop than in the plot that had borne the clover. 



In taking samples on the clover plot, a layer of dry sand about a foot thick was 

 found. The upper limit of this dry sand was fourteen to sixte'en inches below the 

 surface. It contained but 1.12 per cent of moisture. Its presence in the second and 

 third foot explains the very low per cent of moisture at these depths. 



LENGTH OF TIME REQUIRED FOR A HEAVT RAIN TO SOAK INTO A DRY SOIL,. 



On the 21st or July 1.22 inches of rain fell. This was followed on July 26th by the 

 very unusual rainfall of 4.34 inches. After these i-ains the following observations 

 were made on the clover plots before mentioned: 



July 26th 

 July 27th 

 July 28th 

 July 31 St. 



2nd foot. 



Per cent. 

 10.55 



8.08 

 7.68 

 6.78 



Average 

 three feet. 



Per cent. 

 10.64 

 9.83 

 9.40 



7.74 



On July 2fith there was still a layer of dry soil in the third foot. On the 27th this 

 had disappeared and the moisture was more evenly distributed through the three 

 feet. It was not until July .31 that the moisture became normally distributed. This 

 gives an idea of the length of time required for the flow of water in an open sandy 

 soil to the dryer parts. In a less porous soil the time required is much greater, as 

 is shown by the following observations: 



An opportunity was afforded in Field 6 on the two strips of corn ground, the behav- 

 ior of which has been described in the previous pages of this bulletin, to determine 

 the apparent rate and extent of the downward movement of water after rain. Sam- 

 ples were taken September 12th, October 1st and October 22d. As shown in the table 

 of i-ainfall on page 86, this weather was wet almost continuously after the 1st of 

 October-, and on this account the evaporation from the surface was slight. The fol- 

 lowing table shows the per cents of moisture in the two strips to a depth of three 

 feet on the dates given: 



These figures show first that the 2.0.3 inches of rain that fell between September 

 12th and October 1st made no increase in the moisture whatever below the second 

 foot and in the east strip very little below the first. In the third foot, on the other 

 hand, there is actually a decrease. This is difficult to explain, but the statement is 



