AGRICULTURE AND DENDROLOGY. 15 
sodium to tlie amount stated, the influence of this fertilizer 
cannot be said to be great. The average of the quantities 
applied to the two plats is equivalent to a rate of about 273 lbs. 
pr. acre, while the increase in yield over the average of 
unmanured land is but about 3 bushels pr. acre, an increase 
far too small to justify the purchase of this fertilizer. 
In the combinations of nitrate with the other two elements 
it is more difficult to form an opinion of its influence, since it 
cannot be determined with what percentage of the increase each 
deserves to be credited. On plat 1 potash alone produced a 
yield of 8.15 kilograms. On plat 10 the same amount of 
potash, (70 lbs. pr. acre), and 182 lbs. nitrate pr. acre, produced 
but 8.24 kilograms, an increase in the yield of the plat of but 
90 grams, or less than half a bushel pr. acre. Does this small 
increase represent the influence of the nitrate? The super¬ 
phosphate on plat 5, applied at the rate of 122 lbs. pr. acre 
produced a yield of 7.84 kilograms. On the adjoining plat, No. 
6, the same quantity of superphosphate and 182 lbs. nitrate 
pr. acre, produced but 7.78 kilograms, a decrease of 60 grams 
from that of superphosphate alone; while on plat 19, similarly 
manured, but with twice the quantity, there is the only marked 
increase in yield that by any possibility can be ascribed to the 
nitrate. This case I have, however, already referred to. Again, 
on plats 3, 4, 11 and 12, where nitrogen is_combined with super¬ 
phosphate and potash, the yields are actually less than on the 
plats where the two latter were used singly and together. These 
results do not indicate that the nitrogen has had any influence 
on the yield, unless it be an adverse influence, and such a 
theory is scarcely admissible. The same general result will 
be observed in the corresponding plats of series B. 
In one particular the nitrogen seems to have had some 
effect on the crop; not indeed, in the production of grain, but 
in that of straw. In the experiment with irrigated rice the 
sulphate of ammonia showed itself decidedly in the increase of 
the percentage of straw to that of grain. The same is the case 
here though in a less marked degree. If we take the average 
percentage of grain on the unmanured plats as the standard, 
