5» 
Journal of Agricultural Research 
Vol. XI, No. 3 
this as it may, it has recently been shown by Call and Sewell (2), of this 
Station, that just as vigorous nitrate accumulation can take place in 
noncultivated as in cultivated soil. The following results are taken from 
their paper. The figures represent pounds of nitrates gained or lost 
between the given dates. The noncultivated plot was kept bare of 
weeds by scraping the surface. 
1914 
1915 
1916 
Year. 
Period. 
Apr. 5 to Nov. 2... 
j Apr. 15 to Sept. 8. 
j May 29 to Sept. 23 
Average 
Not culti¬ 
vated. 
Cultivated 
3 inches 
deep. 
Cultivated 
6 inches 
deep. 
Pounds. 
Pounds. 
Pounds. 
620 
84 
369 
419 
180 
207 
283 
281 
4 *s 
441 
182 
354 
King and Whitson (5) conducted somewhat similar experiments under 
greenhouse conditions. In one experiment, carried out in the greenhouse, 
soil in cylinders in which various crops had been grown, was found after 
91 days to show an average gain in nitric nitrogen per acre-foot (4,000,000 
pounds) in all cultivated soils of 105.62 pounds. Soil in the nonculti¬ 
vated cylinders showed a gain of 162.42 pounds. In another series, 
which ran for 258 days, the average gain in soil in noncultivated 
cylinders was 325.48 pounds, and in the soil of all cultivated cylinders, 
303.68 pounds per acre-foot. In summarizing they say (p. 9): 
The increase of nitric nitrogen has been greater at all depths, as a rule, where the 
soils have not been cultivated than where they have been cultivated. As a general 
rule, there has been the highest increase of nitric nitrogen in the surface foot, and the 
increase in the third foot has generally exceeded that in the second foot. 
King and Whitson (6) also carried out the only experiments found re¬ 
ported wherein an effort was made under field conditions to increase 
aeration without cultivation. Holes were bored to a depth of 4 feet and 
left open but protected in order to prevent drying out and also to prevent 
surface drainage. These were so arranged that other samples could be 
taken for nitrate analysis at definite distances from the original holes. 
Duplicate sets were arranged and analyzed both after 4 and 10 weeks' 
standing. Below are given the average nitrate contents per foot to a 
depth of 4 feet at the 10-week analysis. 
Holes on number of sides. 44 12 
Distance from holes, inches. 6 8.5 12 24 
Nitrates. 26. 24 23. 94 27. 00 27. 01 
If the figures from any depth, even third and fourth foot layers, are 
studied, there is little to indicate that increasing aeration, as such a 
procedure must have done, increased the nitrate formation. The moisture 
