THE BBOADBALK WHEAT SOILS. 
77 
r.vi'.LK W.—Hroadbalk a-}, rat soils, plats la, U, J ,\ 13, 14, ami / — Supply, esti- 
mated removal, accumulation, and loss of nitrogen hi/ drainage, etc. 
BBS 1881 OW years i : 
Plat 10 
Plat 11 
Plat I-' 
Plat IS 
Plat 14 
Plat 7 
Averatfo 
»»:{ L883 <50 years): 
Plat l"a ." 
Plat 10b 
Plat 11 
Plat YZ 
Plat 18 
Plat 1 1 
Plat 7 . 
Avcra^i' 
Nitrogen per acre per annum in excess of that for plat 5. 
Added 
in ma 
nure. 
I'oUllds. 
Mi 
Remov- 
ed in 
crops. 
Pottndt. 
v z t 
17. 7 
zil 
24.1 
8.0 
U.0 
I5.n 
I7.i) 
81.0 
80.0 
Hi. 
Annually 
ac< u mulat- 
ed in sur- 
face soil. 
Pounds. 
a4.8 
a 11.6 
a 14.6 
a 17.8 
a 15. 5 
a 19. 3 | 
Unaccount- 
Estimated! ed for (sub- 
loss tr,,m s ::i Mr ^ i r 
drain 
pipes. 
I 'min <Is. 
31.2 
88. 5 
24.5 
85. 6 
27.5 
19.0 
OT accumu- 
lation and 
any other 
Pounds. 
87.6 
28.2 
24.7 
l!t.2 
18.9 
21.8 
a 13. 9 
c3.0 
c8.0 
c6.0 
c9.5 
c8.0 
<l> 5 
ell.O 
LV, n 
31.0 
31.0 
2S 5 
24 5 
0.0 
26.7 
25. 1 
44.0 
41.0 
36. 5 
85.0 
31.5 
86.0 
31.0 
35.0 
a Soil accumulation liased on analyses of 1HM1 samples. 
6 8ee note 11 a," Table 26, p. 10. 
' Soil accumulation based on analyses of 1S93 samples. 
The estimated annual quantity of nitrogen in excess of plat 5, 
ielded in crops over the fifty years IS4:>- 1 as compared with the 
hirty years IS.5:MSS:$, is lower throughout, chiefly owing lolhe higher 
yerage yield of nitrogen in plat 5 — namely, 24 pounds per acre per 
nnum instead of 20. J pounds — arrived at by including the earlier 
ears of the experiments, when plat n received dressings of ammo- 
ium salts and gave far higher crops than since 18o2. Then the 
nnual soil accumulation — one-fiftieth of the difference found in 1893 
ii the surface soil in excess of plat — is less than was shown over the 
nirty-year period, there being necessary limits to accumulation, and 
he differences becoming smaller when they are reduced to average 
nnual differences over so many years. When the estimated annual 
nantity unaccounted for is averaged, the fifty-year period shows, as 
re should expect, a greater annual loss. The chief difference is in 
>liit LI, which has accumulated nothing on the average since 1881, 
rhile plat 5, with which it is compared, has only lost about 2 pounds 
er acre per annum. Indeed all the surface soils but that of plat 14 
pe, according to the L893 analyses, somew hat lower in total nitrogen 
ban in L881, and the annual loss of nitrogen in drainage, in propor- 
ion to the nitrogen supplied, would appear to be in later years above 
he average estimates for the iit'i\ years. Now, in 1881 no subsoil 
amples were taken below the third depth, and the conclusion that 
he Loss unaccounted for in the pipe-drainage waters was mainly in 
ubsoil drainage, though a fair deduction, was without means of 
It is therefore interesting to see how far the examination of 
•roof. 
