Experimental Plots at Roihamsted,from 1864 to 1883. 419 
over an average, which, following so dry a March, was very 
beneficial. May was cold and dry, the nights being very cold, 
and vegetation was backward. June was very cold and un- 
settled during the first half of the month ; afterwards the 
weather became warmer, and from the 19th to the 26th thunder- 
storms were frequent, with heavy rain and hail which greatly 
damaged the crop. 
July was dull, unsettled, and wet. Thunderstorms were 
frequent from the 14th to the 16th, The fall of rain was in 
some places over 3 inches ; while in others hailstorms occurred, 
which did considerable injury to the crops. Up to August 8th 
the weather was cold and wet, but after this date it was fine to 
the end of the month. The first week in September was very 
fine and hot, but during the rest of the month there was a great 
deal of wet. 
Table XVII. — Summary of the Results of the Thirty-seventh SsAsoy, 
1879-80. 
PloU. 
10a 
9b 
OA & B 
■a & 
Sa & 
Manures. 
(Quantities per Acre.) 
Produce per Acre. i:c. 
Unmanured 
400 lbs. ammonium-salts alone = Stilbs. N. 
550 lbs. nitrate of soda alone = 86 lbs. N. 
Mixed mineral manure alone 
Mixed mineral manure, and "i 
200 lbs. ammonium-salts = 43 lbs. X. ..] 
Mixed mineral manure, and \ 
400 lbs. ammonium-salts = 86 lbs. X. .. / 
Mixed mineral manure, and . . . . 
550 lbs. nitrate of soda = 86 lbs. X. 
{Mixed mineral manure, and I ^i- 
600 lbs. ammonium-salts = 129 lbs. X. ../ 
Estimated average for the United Kingdom^ 
reckoned at 61 lbs. per bushel J 
Dressed Com. 
Straw 
and 
Chafif. 
Quantity. 
Weight 
per 
BusheL 
TotaU 
Corn, 
}ush. pks. 
11 2 
38 11 
10 2h 
10 1| 
17 2| 
lbs. 
56-9 
60-2 
54-9 
53-5 
59-2 
lbs. 
689 
2373 
645 
654 
1083 
lbs. 
1149 
3902 
1242 
1420 
1735 
26 3i 
59-8 
1664 
2911 
34 2 
59-8 
2149 
4006 
34 Oi 
57-8 
2130 
4391 
35 11 
59-1 
2203 
4476 
30 0 
CIO 
The wheat crop of 1880 gave a higher produce — 38 bushels 
per acre — on the plot which receives farmyard-manure than was 
obtained upon any of the artificially manured plots. The 
large store of latent fertility in the dunged plot — which may 
become active at any moment — makes the yield of wheat in 
this plot subject to fluctuations of a different character from 
those of the other manured plots. The estimated yield of the 
crop of the country was rather above the average. 
