Section II. 
THE BROADBALK WHEAT SOILS. 
SUMMARIZED HISTORY. 
These plats have been under experimental cultivation since 1843, 
and have continuously grown wheat, the lately harvested crop of 1900 
having been their fifty-seventh. The' continuously unmanured plats 
are still giving their 12 to 13 bushels a year, while the well-manured 
plats are giving from 30 to 40 bushels. 
The general history of the field and the practical results of the 
influence of the various modes of manuring upon the crops produced 
were very fully described and discussed by Sir Henry Gilbert in the 
lectures which he delivered here in 1893. This makes it unnecessary 
that I should take up your attention by dwelling on what may be 
called the above-ground or vegetative or economical effects of the 
various manures. It is rather on the underground results of this 
continuous corn growing, under so many different circumstances, that 
I have to discourse to you. It is necessary, however, for a discussion 
of the soils themselves that we should have before us a summary of 
the history of each plat, and as the soil analyses end tor the present 
with the samples taken in 1893, it seems convenient to adopt, with 
some minor modifications, the summary given in the annual "Memo- 
randa " issued from Rothamsted recording the results up to the end 
of 1893. Table 1 shows the number or special mark of each plat, a 
summarized history of its mode of manuring for fifty years, the average 
product of grain and straw for the twenty-one years, 1852-1872; for the 
twenty-one years, 1873-1893; for the forty-two years, 1852-1893, and 
also for the six years, 1889-1894. 
Table 1. — Broadbalk wheat plat* — Historical summary of manurings and crop- 
pings to 1804. 
Average yield per acre. 
Plat. 
Annual manuring per acre (over 
21 years 
(1852-1872). 
21 years 
(1873-1893). 
42 years 
(1852-1893). 
(5 years 
(1889-1894). 
50 years). 
Wheal 
Straw 
Wheal 
\ 
h 
43 
Wheal 
Straw 
Wheat 
Straw 
14 tons farmyard manure, com- 
Bush. 
Cwt. 
Bush. 
Cwt. 
Bush. 
Cwt. 
Bush. 
Cwt. 
30} 
28| 
L4 tons farmyard manure (1843-44 
and every year since) 
Unmanurod continuously 
Unmanured continuously since 
1852 1 previously superphosphate 
and ammonium ^alts) 
3 
35} 
14} 
33| 
m 
§84 
Hi 
aoj 
8} 
34f 
121 
321 
108 
40| 
12J 
38f 
9* 
4 
15J 
135 
Hi 
8| 
181 
10J 
134 
9fr 
1L' 
