244 
Journal of Agricultural Research 
Vol. IX, No. 7 
EFFECT OF RAINFALL ON THE DISTRIBUTION OF NITRATES IN 
CITRUS SOILS 
The effect of rainfall on the distribution of nitric nitrogen during the 
season of 1914-15 is shown in figure 18. The rainfall from November 
12, 1914, to January 23, 1915, amounted to 3.36 inches, but it fell in 
light showers over a period of nearly 10 weeks and seems to have had 
Fig, 18.—Diagram showing the effect of rainfall November 12, 1914, to July 15, 1915, on the distribution 
of nitrates in soils at Riverside, Cal. 
little effect on the movement of nitrates in the soil. From January 23 
to February 7 the rainfall amounted to 4.22 inches. The effect of the 
rainfall during this period on the distribution of nitrates is very marked. 
In the soils which had received commercial. fertilizers the nitrates in 
the upper 6 inches fell from 3.62 to 0.31 mgm. There was no increase 
in nitrates at a depth of 6 to 18 inches; but at a depth of 18 to 30 inches 
