NITRIFYTNd POWER OF SOILS AT DIFFERENT DEPTHS. 



13 



Fig. 3. — Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths 

 from plat 120, Trucliee-Carson Experiment Farm. Original nitrate present in samples: Depth, to 6 

 inches, 15.36 parts per million; 6 to 12 inches, 8.64; 12 to 18 inches, 6.72; 18 to 24 inches, 3.84; 24 to 36 inches, 



2.88. 



in the previous paragraph. The samples from plat 120 show nitrifica- 

 tion varying rather irregularly with depth. Samples from plat 130 



^^ 20 



OePTH ^r W/^/C^ S/JMPL£S iV£/?E Z^/fZTl/. 



fo 



Fig. 4. — Diagram showing the nitrification of ammonium sulphate in samples of soil from different depths 

 from plat 130, Tnukee-rarson F.xperinienl Farm. Original nitrale present in samples: Depth, to 

 Lnches, 13.3 parts per million; li to 12 inches, 6.72; 12 to 18 inches, 3.6; 18 to 24 inches, 7.23; 24 to 3ii inches, 

 14.4. 



211 



