1919] 



Pendleton : A Study of Soil Types 



427 



As regards nitrification in general there is difficulty in showing 

 any greater resemblance between the samples of a type than there is 

 from type to type. In certain features, however, the types are some- 

 what distinct: (1) The relation of the nitrification of the soil's own 

 nitrogen to the soil's action upon added nitrogen is rather distinct 

 for the types. The normal soil in the San Joaquin type gave a much 

 larger per cent of nitrogen than did the soil plus the added nitrogen 

 containing materials. In the Diablo type (fig. L'.~> the normal soil 

 was about midway in its production as compared with the soils to 

 which the nitrogenous materials were added. In the Banford fine 

 sandy loam the normal soils gave a much lower percentage nitrifica- 

 tion than in the greater number of instances where the soils were 

 treated with nitrogenous materials. (2) The relative nitrification of 

 the various nitrogenous materials is somewhat distinct for the types. 

 The Diablo, Altamont, and San Joaquin show the ammonium sulfate 

 first, with the cottonseed meal second, and the dried blood third. The 

 Hanford type shows cottonseed meal first, with dried blood second and 

 ammonium sulfate third. 



Table 37 — Nitrification 



Diablo Clay Adobe 



Soil nitrogen and 

 dried blood 



Soil nitrogen and 

 cottonseed meal 



e| = g s^ 2§ 3 s £.r 



~-5 o.S ;-'= :--= P-S = = 



fc fri fc V - S- 



2.20 347.22 0.63 5.00 198.42 2.50 



Tr. 336.14 Tr. 187.34 



0.07 300.02 0.02 0.16 151.22 



4.07 334.56 1.22 6.82 185.76 3.77 



0.08 310.40 0.19 L61.60 0.12 



0.80 302.34 0.80 153.54 



1.66 326.62 0.51 

 0.19 307.58 0.06 



3.76 L77.82 2.12 

 0.97 158.78 0.61 



6-A 0.59 116.58 0.51 

 6-B 1.65 101.54 1.63 

 6-C 0.96 78.10 1.23 



4.58 158.98 2.88 



3.00 143.94 2.08 



1.01 120.50 0.84 



6.88 210.58 3.26 



i 2.32 



0.47 17i'. 1" 0.27 



