THE BROADBALK WHKAT SOILS. 
129 
TABLB to.—Broadbalk wheat soils {1865, 1881, and 1803)— First inches only— 
NlTEOGl n i" r acre in fine dry soil, and differences for each period; also the 
amounts, + or — , plat 5. 
Nitrogen per acre in fine dry soil. 
Plat 
Annual manuring. 
1881, 
1893, 
4- or - 
, plat 5. 
1865. 
1881. 
1893. 
4- or — 
4- or — 

1865. 
1881. 
1865. 
1881. 
1893. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
— H 
_ 
r arni yar< 1 vin; i ti u F6 B1&06 
1HK4 
4-1,298 
3b 
F arm yard maim rt*. 1 y< ';ir> 
l.:u:! 
4.309 
1,976 
+ 56 
4-577 
+ 1 . 561 
4-1.856 
4-2, 459 
8 
•> J22 
2,tJl*i 
2. 137 
-106 
-179 
— 60 
"t* 
73 
- 80 
4 
1 TlTll'lTltlt'i'/l wj||n< 1 v",'* 
2.3*3 
2,349 
- 34 
1(50 
— 168 
1* nil in i ncrnls - 
2. 782 
:.'.:>»:; 
2.5 17 
-239 
- 26 
N 
1 UII fill I J • I <11» <illLX (lllliliO 
111 1 1 1 11 Hill t S .... .... .... .... 

2. 887 
8,790 

— 77 
j 
T 
884 
4- 273 
■ 
do 
8,084 
8, 180 
8,071 
+ 95 
158 
f 252 
4- 
588 
4- 454 
g 
-241 
4- 
724 
4- 509 
!*a 
1'* 1 1 1 1 I 1 1 1 1 1 1 » 1*11 1 U fiill] ^...llltlTll 
3Jj 1 ■•••*.• — r * ■ 
3.(154 
a, 1 1 1 
8,888 
4- 57 
-218 
4- 272 
+ 
668 
4- 376 
9b 
^<hiiuih nitrato onl\ 
8, nso 
2.743 
- 16 
4- 
216 
4- 236 
K>ii 
Ammonium salts (no min- 

2. m 
8,881 
2.598 
- so 
- 83 
— 21 
4- 
138 
4- 81 
KHi 
AiiiiiiDiiiuiu salts < no miii- 
2.689 
~. BOB 
- 21 
+ 
146 
4- 151 
11 
Puosplmtes and ammo 
nium salts 
8/9M 
8,808 
8,001 
-- 111 
- 5 
+ 184 
4- 
363 
4- :i84 
13" 
Pliosj >lia t * *s. sodium, and 
ammonium salts 
t BOO 
2.901 
8,878 
- 116 
+ 217 
+ 
451 
-1- 361 
18 
Phosphates, potassium, and 
2.UKI 
3.IIKH 
8,881 
4-104 
-367 
4- 202 
+ 
545 
4- 304 
M 
Phosphates, magnesium, 
and ammonium stilts 
8,881 
3,(U5 
3. 122 
4- 24 
4-107 
21 m 
4- 
472 
4- 605 
U 
Full minerals and ammo- 
nium salts tautulnn » . . 
8,084 
3,080 
+ 26 
+ 
511 
4- 563 
18 
Full minerals and sodium 
nitrate sinoo I8M 1 1MB 
1883 unmanured ) 
.3, i:J7 
8, Ttd 
8,878 
-:{73 
+ 114 
4- 355 
4- 
221 
4- 861 
I Full minerals and ammo-l 
8,80 
ft 888 
4- 75 
4- 
878 
4- 379 
S 
j nium salts. transposed in 
{ 
8,888 
3.122 
• 881 
+ 
860 
4- 605 
19 
3. isii 
3,377 
4-191 
4- 
643 
4- 8(50 
Generally we see thai on the chemical plat s the tendency, even 
under liberal I real men 1 . has been toward decline rather than increase 
pf accumulated nitrogen in later years, following on an earlier period 
of gain. In fact, we seem to see in progress the attainment of that 
equilibrium which Professor Warington pointed out to you in 1891 
as naturally tending to establish itself under any mammal conditions 
in a drained and aerated soil. Up to a certain point the increase of 
crop and weed residue, induced by liberal manuring, produces accu- 
mulation of organic matter; but this increase furnishes increased 
pabulum for the myriads of soil microbes, fost ering their growth and 
increasing their activity, so that they destroy the excess of organic 
matter that helped them to multiply. They then become less active, 
and a balance is struck between the annual supply of organic food 
furnished to them by crop and root residues and their annual potency 
to break it down and destroy it. On such an explanation each plat 
should in time arrive at its own point of average equilibrium as 
regards nitrogen contents. 
On this supposition it may be said that on plat 3 (unmanured for 
fifty years) the conditions arc less favorable for bacterial multiplica- 
9385— No. 106—02 9 
