Feb. 26,1917 
Effect of Water and Manure on Nitrates in Soils 
34i 
The experiment was begun in 1911, but only results with the nitrate 
and moisture content of the soils for the midseason period were taken 
during that year. No determinations were made in 1912, but mid¬ 
summer data for 1913 and complete results for the fall seasons of 1913, 
1914, and 1915 are included. As the season of the year is thought to 
influence the production of nitrates to quite an extent and because the 
water applied, as well as the depths sampled, varied, the two preliminary 
trials are considered separately. 
Preliminary Tests 
SUMMER OF 19II 
The samples taken on August 7, 1911, include only the first 3 feet of 
soil at a time when the most water applied on any plot was 15 inches. 
Figures 5 and 6 give the average moisture and nitrates to a depth of 3 
feet, figure 5 representing the cropped and figure 6 the uncropped plots. 
Manure 
Applied 
Fig. 6.—Graph showing the soil moisture and nitrates on August 7, 1911, to a depth of 3 feet in fallow soi] 
to which different quantities of water and manure had been applied. 
On an average the cropped plots receiving no manure contained more 
water than those receiving either 5 or 15 tons, and the difference is most 
noticeable with the larger applications of irrigation water. In depth the 
first foot of the 15-ton-of-manure plots contained more water than those 
with no manure, and the first foot of the 5-ton plots proportionately 
more than the other feet when compared with the unmanured. For 
these 3 feet the moisture increased with the depth of soil. The land 
receiving manure at the rate of 5 tons contained an average of about 3 
per cent less water than that receiving none or 15 tons, and was more than 
this for the larger quantities of water applied. 
While the nitrates in the cropped plots to which 5 tons of manure were 
added were higher than those receiving none, where no water and 5 
inches of water had been applied, the average for the unmanured plots 
was higher than that of either of the manurial treatment soils. The 
third foot of the three treatments differed little. 
