TH6 JOUHNAb 



or 



T^Iie department of Mgricuffure 



OF LIBRA 



NEW Y 



VICTORIA. ^^^'^^i 



Vol. X. PaPt 7. loth July, 1912. 



IiNFLUENCE OF CERTAIN SOiL CONSTITUENTS UPON 



NITIUFICATION. 



By John W. t'atcrscni, B.Sc, Ph.D.. Experimentalist, and P. K. Scott, 

 Chemist for Agriculture. 



Nitrification is the process whereby nitrates are formed in soils. Some 

 other forms of nitrogen can be used by crops, but the nitrate form is re- 

 quired in order to get a paying crop. The nature and conditions of nitri- 

 fication were described in the May issue of this Journal. Experiments 

 were quoted showing how the moisture conditions of the soil affected the 

 change. 



In one of the soils used in the moisture experiments there appeared 

 to be a deficiency of lime as revealed bv chemical analysis, and on this 

 soil nitrification was somewhat slow even under the best moisture condi- 

 tions. It seemed desirable, therefore, to set up a new set of experiments 

 with the soil in (juestion in order to find whether an addition of lime 

 would accelerate matters. The results form the principal subject of this 

 report. 



Lime is usually applied to land in one of two forms. It is applied 

 as burnt, hot, or caustic lime — lime proper — and this is the most active 

 form in which to appFv lime. Again, it may be applied as chalk or 

 ground limestone — carbonate of lime — and this form of lime is milder in 

 its action. Slaked lime is a third chemical form of I'me, but it acts just 

 like hot lime, and is orie-third heavier than hot lime, without containing 

 more lime. 



In these experiments, hot lime has been tried on the soil in two different 

 quantities. Mild, lime has also been tried in two quantities, equivalent 

 in each case to an application of hot lime. With pure materials 56 

 parts of hot lime contain the same lime as 100 of mild lime. 



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