for Twenty Years in succession on the same Land. 139 
time until harvest, and, at the same time, unusually liij^h tem- 
peratures and dry atmosphere, the crop was, for the locality, very 
early cut, namely, on July 31, and it was carted on August 5. 
The deficiency of both corn and straw is throughout very con- 
siderable, but proportionally the greater the more defective the 
manuring. Thus, compared with the average of the twenty 
years in each case, the deficiency of total produce, corn and 
straw together, was with farmyard-manure only about one-tenth, 
with mixed mineral manure and ammonia-salts (4 A), and with 
mixed mineral manure and rape-cake, about one-fourth, but 
with mineral manure alone, or ammonia-salts alone, about one- 
third. Further, in these cases of the more defective manuring, 
and the more deficient total crop, the proportion of corn to straw 
is below the average, whilst, with the nitrogenous and mineral 
manure together, as well as with farmyard-manure, the pro- 
portion of corn to straw is rather higher than the average. 
Deficient as was the quantity, the quality was, however, in all 
cases high ; and the higher the more liberal the conditions of 
manuring. Thus, the weight per bushel was between 55 and 
56 lbs. with the mixed mineral manure and ammonia-salts, and 
with the mixed mineral manure and rape-cake, and was over 
57 lbs. with farmyard-manure. 
It will be borne in mind that, during the first six years of 
the twenty (1852-1857), plot 4AA had annually twice as 
much ammonia-salts as 4 A, but that, during the next ten years 
(1858-1867), only the same quantity of ammonia-salts was ap- 
plied as on 4 A, namely, 200 lbs. per acre per annum ; and 
reference to the tables will show that theie has continued to be 
some excess of produce on 4 A A, as compared with 4 A, due to 
the unexhausted residue from the excessive supply during the 
first six years. For the year 1868, and subsequently, however, 
an amount of nitrate of soda, containing the same quantity of 
nitrogen, has annually been substituted on plot 4 A A for the 
200 lbs. of ammonia-salts applied during the previous ten years; 
and it will be seen that, in this year of drought, the plot with the 
nitrate gives nearly 11 bushels more corn, and about 5 cwts. more 
straw, than the plot with an equivalent quantity of nitrogen as 
ammonia-salts. This amount of excess is much greater than has 
been obtained in any succeeding year hitherto ; though in 1 870, 
which was also a year of drought, the excess of produce with the 
nitrate was again very considerable. 
In a paper in a former volume of this Journal,* we showed 
that the soil of the plot in the experimental wheat-field which 
Vol. vii.— s.s. Part I.— "Effects of the Drought of 1870 on some of the Ex- 
perimental Crops at Kothamsted." 
