Market Value of Wlieat and Barley Grown in 1889. 433 
The reader must also bear in mind that as the arrangement of the 
manures of the different plots is based on actual and comparative 
composition, regardless of cost, the market values of the grain 
supplied by the valuer cannot be used to determine the actual or 
comparative profit or loss per acre on the different plots ; and, 
further, that the manures are not the only influences which affect 
the growth and productiveness of the crops. Lawes and Gilbert have 
shown in various memoirs that both the quantity and quality of 
the crop depend, in the first instance, on the fitness of the varying 
climatic conditions — the temperature, moisture, and sunlight- — to 
the different stages in the life of the plant. 
A. "Wheat. 
The first experimental wheat crop in Broadbalk field was grown 
in 1844, so that the crop of 1889 was the forty-sixth in succession 
on the same land. The same description of manure has been applied 
to the same plots for 36 years (from 1852), and indeed, with some 
exceptions, since the beginning of the experiments. 
Until 1876-7 the manures were applied in the autumn, before the 
seed was sown, except the nitrate of soda which was used in spring. 
In consequence of the loss of nitrogen by drainage, the ammonia salts, 
as well as the nitrate, were applied in spring for the six crops 1878-83 ; 
since 1884 each ammonia plot has received 100 lb. of ammonia salts 
in the autumn with the minerals, and the balance as a top-dressing 
in spring. The only exceptions are Nos. 25 and 26, which, since 
1878, have had the whole of the ammonia salts applied with the 
minerals in autumn. 
The plots are six-tenths of an acre in size. They have been 
divided into two equal portions, except those unmanured, those with 
farmyard manure, and that with rape-cake. Both portions have 
been similarly treated since 1880 ; but previously one-half had 
received at first a mixture of soluble silicates in addition to the 
other manures, and afterwards the straw produced on the plots was 
cut and applied. This has, however, been discontinued since 1880. The 
half-plots receiving this exceptional treatment are numbered in 
Table I. on page 434 as 5, 7, 9, 11, 13, 17, 19, 21, 23, 25, 27, 29, 31. 
The valuer went down to Rothamsted to value the samples on 
October 25, 1889. The average market price of home-gi-own wheat 
in England on that date was 30s. 4d. per quarter. 
On the results tabulated here, Dr. Gilbert observes : — " It is 
seen that, if we exclude Nos. 14 to 18 grown under conditions of very 
abnormal exhaustion of certain mineral constituents, Nos. 1 to 13, 
19 to 24, 27 and 28 are all priced at 32s. per quarter ; Nos. 25 and 
26 at 6c/. more, namely, 32s. Qd. ; and Nos. 29 to 33 at 6d. less, that 
is, 31s. 6d. This is the case notwithstanding there was the greatest 
possible variety of manuring, and a range in the amounts of produce 
among these 28 plots of from 9^ to 40.^ bushels per acre. It is 
clear, therefore, that, excepting under certain abnormal conditions, 
the character of the manuring has very little direct influence on the 
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