Summer Fallowing and Soil Moisture 155 



in the water content of the soil under the two treatments was 

 found to be as given in the table below : 



Not fallow ground rear by 



Fallow ground Not fallow ground Timothy and Clover 



No crop Corn bluegrass in pasture 



PER CENT PER CENT PER CENT PKR CENT 



0-6 inches 16.23 6.97 6.55 8.3S) 



(5-12 " 17.74 7.8 7.62 8.48 



12-18 " 19.88 11.6 11.49 12.42 



18-24 " 19.84 11.98 13.58 13.27 



24-30 " 18.56 10.84 13.26 13.52 



40-43 " 15.9 4.17 18.51 9.53 



In the first half of this table, where the soils are closely 

 similar and entirely comparable in every way, it will be seen 

 that the ground bearing no crop is much more moist than is 

 that on which the corn was grown ; and since a good degree of 

 moisture in the surface foot of soil is absolutely indispensable 

 to the processes which develop the available nitrates, it can readily 

 be seen how much more favorable were the conditions for the for- 

 mation of nitrates on the fallow ground than they were on the 

 ground which was not fallow. In the last two columns -of the 

 table, there has been set down, for the sake of comparison, the 

 results of moisture determinations at corresponding depths on 

 lands bearing pastured clover in one case and hay in the other. 

 These samples were taken from essentially the same kinds of soil, 

 and but a short distance from where the other samples were 

 taken, and illustrate in a very forcible manner how thoroughly 

 the surface foot of soil in a dry time loses its moisture when it 

 is occupied by a crop, and how unfavorable are the conditions 

 for nitrification in the soil when compared with those offered by 

 the fallow ground. 



In the following spring, after the frost was out of the ground, 

 and the fall and winter rains and snows had given their moisture 

 to the plots under experiment, samples of soil were again taken, 

 to learn what the relative conditions were at this time, and the 

 results found are given in the table below, where both the per- 



