THK BROADBALK WHEAT SOILS. 131 
Table 70. — BroadbaJk wheat soils, etc. — Continued. 
Sl'MMARY— FIRST, SECOND, AND THIRD DEPTHS (27 INCHES'. 
Annual manuring- 
i»a 
in.-, 
10b 
n 
IS 
18 
1 1 
I » 
Ifi 
17 
18 
1!» 
Nitro- 
gen in 
manure 
per acre 
per an- 
num. 
Farmyard manure since 1884 
Farmyard manure VJ years 
Uiimaiiiircd 
L'nmanuivd since 1862 
Full minerals 
Full minerals and ammnnium salts 
do 
do 
Full minerals and sodium mtrat«- . .. 
Sodium nitrate only . . 
Ammonium s:ilts < no minerals simv < . 
Ammonium salts i no iniiifials sin'-., lsvi i 
Phosphates and ammonium salts. . . ... 
Phosphates, sodium, and ammonium salts 
Phosphates, potassium, and ammonium salts 
Phosphates, magnesium, and ammonium salts 
Full minerals and ammonium salts autumn > 
Full minerals and sodium nit rate since |s>( 
I Full minerals and ammonium salts transposed in alternate 
I years 
Rape cako 
Pf minis. 
800 
SNI 


I) 
43 
86 
4:t 
43 
86 
S6 
ws 
1881. 
Pounds. 
51.37 
17.82 
IV 15 
84.50 
38. !C 
37.51 
4.3. 10 
38. •» 
54. 37 
38. IS 
28.51 
31.05 
80. 12 
84.23 
L's. ;,f, 
38.38 
a 89. 8D 
81.66 
25. 1 1 
3i.:m 
a N<» nitrate in L88L 
The climatic conditions in the two years were by no means alike, 
except in so far as that in both years they resulted in the crops being 
exceptionally light. In L88] there was exceedingly heavy rain imme- 
diately after the crop was ent in Augusl , amount ing to nearly »> indies; 
and this rain mast have tot the most part washed downward the 
nitrates already existing in the upper layers of the soil and unutil- 
ized by the crop. Indeed (as was pointed out in Professor Waring- 
ton's lectures to you in 1891), the analyses of drainage waters collected 
from the plats at the time showed that this was the ease. The field 
was plowed in September, and the moisture, warmth, and aeration of 
the soil produced exceedingly rapid autumn nitrification before the 
soils were sampled in October. The progress of this nitrification was 
most interestingly shown in the successive samples of drainage water 
examined during the period. 1 
It seems probable, then, that the greater part of the nitrates found 
in the first and second depths in 1 SSI was due to nitrification occurring 
subsequent ly to harvest . 
In L893 there had been a spring and summer drought, most unfavor- 
able for early nit rilicat ion. I Jet ween harvest and soil sampling there 
was, however, as we have seen when discussing the 1 893 results, 4£ 
inches of rain, and three-fourths inch more during the time of 
sampling, with the result that much of the nitrates existing unused at 
harvest must have been washed into the second depth. But the wash- 
1 Professor Warington's Lectures, U. S. Dept. Agr.. Office of Experiment Stations 
Bui. 8, p. 85. 
