AGRICULTURE AND DENDROLOGY. 
9 
EFFECTS OF NITROGEN. 
As miglit have been expected, the highest yield was obtained 
from plat 5 to which a complete fertilizer was applied in large 
quantity. But the nitrogen is evidently the most active agent 
in bringing about this result ; for the next highest yield is 
produced by sulphate of ammonia alone, and the two following 
both have nitrogen in considerable quantity. On the other 
hand, the four lowest yields are the products of fertilizers 
containing no nitrogen at all ; and of the eight intermediate 
yields, from 5tli to 12th inclusive, five contain nitrogen. The 
question which suggests itself, as to the quantity which 
limits the beneficial effects of nitrogen cannot be answered 
from these figures. But it appears that its influence for good 
was exceeded in the case of plat 9, which ranks only lltli in 
the order of yield, although it received double the standard 
quantity of sulphate of ammonia, while plat 1, to which was 
applied but half as much, ranks second. The inference must 
be that the nitrogen was so much in excess of the natural 
supply of the other necessary elements in the soil, as to be 
injurious to the development of the seed. This view is 
confirmed by a reference to the weights of the grain in columns 
4 and 5, and to the amount of seed pr. panicle in column 7. 
The combination of nitrogen and potash produced a better 
yield than nitrogen and phosphoric acid, the former ranking 
7th the latter 12th in the order of yield. With the single 
exception of plat 10, the nitrogen was furnished in the form of 
sulphate of ammonia. It was selected on purpose, as it has 
been proved by Dr. 0. Kellner that irrigated rice prefers the 
nitrogen in the form of ammonia. Nitrification does not take 
place to any extent under water, and the plants absorb it as 
ammonia. This seems to be confirmed in the case of plat 10, 
where nitrate of soda was substituted for sulphate of ammonia, 
and although the plat was supplied with a complete fertilizer, 
in which was nitrate of soda at the rate of 552 lbs. pr. acre, it 
ranks but 9th in the order of yield and has much less influence 
on the tillering of the plants and the weight of the seed than 
ammonia. 
