4!)4 



EXPERIMENT STATION RECORD. 



The above table clearly shows that aeration and pu-lverization of the 

 soil had a marked influence on the production of nitrates. The soils 

 which had been exposed to the air in the station building during six 

 weeks in every case gave very much larger amounts of nitrates than 

 those left in place. Do the preceding figures furnish a iiiir basis for 

 determining the nitric nitrogen which a hectare of soil would furnish 

 if it were submitted to a pulverization as complete as that to which 

 these samples were subjected ? 



It is usually assumed that a hectare of soil to a depth of 35 cubic 

 meters weighs 4,000 tons.' This is calculated on the assumption that tlie 

 3,500 cubic meters of a hectare of soil to a depth of 35 cubic meters has 

 a density ranging between 1.1 and 1.2. We must not suppose, however, 

 that the pulverization of a soil in place extends to a depth of 35 cubic 

 meters, but we may safely assume that the stirring of the soil extends 

 at least to one-fourth this depth; that is, the stirred layer of a hectare 

 weighs 1,000 tons. If we multiply the figures obtained above on 100 

 gm. by 10,000,000 we have the following figures per hectare of 1,000 

 tons: 



Nitric nitrogen per hectare of 1,0U0 tons. 



Lot 1, moistened 

 Grignon : 



Unstirred 



Stirred 



Martnilhat; 



Unstirred . 



Stirred 



Palbost ; 



Uustirred 



Stirred 



KiloErrams. 



20 

 440 



20 

 510 



20 

 710 



Lot 2, umnoistened 

 Grignon : 



Unstirred 



Stirred 



Marmilhat: 



Uustirred 



Stirred 



Palbost: 



Unstirred 



Stirred 



Kilograms. 



20 

 390 



20 

 461) 



20 

 570 



For the purpose of collecting the drainage waters the soils which were 

 carried to the hiboratory for experiment were placed in pots similar to 

 those in which the undisturbeil soil remained. Some of these pots fur- 

 nished drainage water on January 25 and March 8 which, on analysis, 

 gave the following results : 



Composition of the drainage water of stirred and unstirred soils. 



Soil. 



Grignon : 



Unstirred . 



Stirred 



Unstirred . 



Stirred 



Marmilliat: 



Unstirred . 



Stirred 



Unstirred . 



Stirred . . . . 

 Palbost : 



Unstirred . 



Stirred 



Unstirred . 



Stirred 



Amotuit of 



l)at 6 of I 

 coUecting 



! Co. 



Jan. 25 { ^'^OO 



Mar. 8 



Jan. 25 

 Mar. 8 



Jan. 25 

 Mar. 8 



6,400 

 3,470 



Nitric nitro- 

 gen found. 



Grams. 

 0.036 



.160 

 8.258 



2,370 

 6,910 

 5,540 



4,640 

 1,670 

 6,840 

 3,950 



6.870 



.186 



6.890 



.025 

 7.000 



.192 

 2.256 



Nitric nitro- 

 gen per cubic 

 meter of 

 drainage 

 water. 



Nitric nitro- 

 gen per hec- 

 tare of 1,000 

 tons. 



Grams. 



25. 

 2, 380. 



2, 400 



128, 870 



1, 390. 



27. 



1, 240. 



5. 



1, 420. 



28. 



570. 



49, 350 



2,640 



103, 050 



10.' 



375 

 OOIJ 

 2, 880 

 33, 840 



1 The metric ton containing 2, 204.6 lbs. 



