364 



EXPKlllMENT STATION RECORD. 



cnlat(Ml. Tliis was found to Ix' the very lieavy application of (!(),(»0() kg. 

 per liectare. Both maimrcd and uninaimred soils were exposed to tlie 

 rainfall during an entire year, i^Iarcli, 1891, to March, 1802, and the 

 drainage water was collected and analyzed. The results in kilograms 

 per hectare are shown in the following table: 



Xiiric iiitro(/en in ilic dr(tin<u/c water dtirhig different srnsons, March, ISDl, to March, 1S92. 



The preceding figures are very high. As already stated, they greatly 

 exceed those given by Lawes, Cxilbert, and Warington for the drainage 

 water of soils without vegetation. 



If we compare the figures in the last column we find that the manure 

 has nitrified at very different rates in the ditt'erent soils. In the very 

 permeable light soil of Grignonthe total quantity of nitrogen nitrified, 

 in both the manured and unmanni'ed soil, was much higher than that 

 in the strong soil of Wardrecijues, or in the soils of the Limagne. 



We observe, also, that the nitrification of the nitrogenous matter of 

 the manure was more rapid in the spring than m summer, autumn, or 

 winter. This is without doubt due to the fact that the nitric ferments 

 act first on the ammonia of the manure, which is much more readdy 

 nitrifiable than the organic substances witli which it is mixed. Never- 

 theless in all cases soils containing residues of previous manuring have 

 manifested more active nitrification, as measured by the total (juantity 

 of nitric nitrogen obtained, than those which had not been manured. 



In the preceding experiments nitrification has been very active, the 

 manuring copi;»us, and the figures obtained have been much higher 

 than tliose yielded by soils in place. They may, therefore, be taken as 

 the T^aximnm of the amount of the nitrogen of manure which will be 

 transformed into assimilable nitrates during the first year. If we com- 



