732 



EXPERIMENT STATION RECORD. 



soils of Mauritius it was poor in lime, and although it contained a con- 

 siderable amount of organic nitrogen it was not very productive, 

 because uitrification went on in it very slowly. 



The nitrogenous fertilizers tested in different cases were sulphate of 

 ammonia (20.5 per cent of nitrogen), dried blood (13 per cent), oil cake 

 (C.I per cent i, fertilizer (5.4 per cent), and fish guano (6.8 per cent). In 

 duplicate tests of sulphate, blood, and oil cake 5 per cent of calcium 

 carbonate (in form of ground calcareous sea sand) and 1 per cent of 

 lime (50 per cent caustic lime) were applied in addition to the nitrogen- 

 ous fertilizers. The results are tabulated in full for each experiment. 



The results obtained in the last series of experiments, which is prob- 

 ably the most complete, were as follows: 



A mounts of nitric nitrogen in 100 grams of soil at different dates. 



Ordinary soil 



Soil with calcium carbonate 



Soil with lime 



Soil with amine mi i nil sulphate 



Soil u iili ammonium sulphate and cal- 

 cium carbonate 



Soil with dried blood 



Soil with dried blood and calcium car- 

 bonate 



Soil with oil cake 



Soil with oil cake and calcium carbonate 



Soil with fertilizer 



Soil with tish guano 



June 11. 



Mg. 

 4.2 

 6.2 

 17.0 

 22.0 



75.0 

 66.0 



123. 

 59.0 

 97.0 

 64. 

 74.0 



July 12. 



Mg. 

 5.0 



7.:: 

 20. o 

 29. 



133.0 

 74.0 



151.0 



82. o 

 139. i) 

 90. it 



110. 



Aug. 14. 



Mg. 



0.0 



o. o 



19.0 

 35.0 



186.0 



85.0 



159.0 

 95.0 

 137. 

 111.11 

 113.0 



Sept. 15. 



Mg. 



8.3 

 PJ. 

 24. 

 44.0 



190.0 



88.0 



158.0 

 101.0 



148.0 

 127. ii 

 137. 



Nov. 26. 



Mg. 



8.0 

 10.0 

 28.0 

 51.0 



187.0 

 101.0 



174.0 



139.0 

 155.0 

 140.0 

 161.0 



Feb. 20. 



8.0 

 11.0 

 28.0 

 85.0 



188.0 

 101.0 



178.0 

 155.0 

 160 

 145.0 

 104.0 



Iii unlimed soil in all cases sulphate of ammonia nitrified more slowly 

 than the other fertilizing materials, the order of nitrification standing 

 as follows: Fish guano (most rapid), fertilizer, oil cake, blood, and sul- 

 phate of ammonia. The addition of lime, especially of caustic lime, 

 increased nitrification to a marked extent in both the fertilized and 

 unfertilized soil, although its action was more energetic on the nitrogen 

 of the fertilizers than ou that of the soil. The slowness of nitrification 

 of the sulphate of ammonia appeared to be due to a deficiency of sali- 

 fiable bases in the soil, since on the addition of lime the sulphate 

 readily nitrified. The other substances used had an advantage over 

 the sulphate of ammonia in that the nitrogen in them was associated 

 with more or less of salifiable bases. 



The results indicate in general that in soils well supplied with lime, 

 in a climate such as that of Mauritius, there is not as much difference 

 in the assimilability of the different fertilizers tested as has often been 

 supposed. They also emphasize the importance of lime in rendering 

 the nitrogen of the soil available. 



The mechanics of soil moisture, L. J. Briggs ( U. 8. T)ept. Agr., 

 Division of Soils Huh 10, pp. 24, Jigs. 7).— This bulletin presents "the 

 application of certain dynamical principles to the problems attending 

 the movement and retention of soil moisture." A technical discussion 



