manure, and the
other dressed with 252 lbs. of pure carbonate of ammonia per acre. The
half without manure, (5a), did not produce quite as much grain and straw
as the plot which had received no manure for two years in succession.
But the wheat was of better quality, weighing 1 lb. more per bushel than
the other. Still it is sufficiently evident that superphosphate of lime
did no good so far as increasing the growth was concerned, either the
first year it was applied, or the year following.
The carbonate of ammonia was dissolved in water and sprinkled over the
growing wheat at three different times during the spring. You see this
manure, which contains no _mineral_ matter at all, gives an increase of
nearly 4 bushels of grain per acre, and an increase of 887 lbs. of
straw.
"Wait a moment," said the Deacon, "is not 887 lbs. of straw to 4 bushels
of grain an unusually large proportion of straw to grain? I have heard
you say that 100 lbs. of straw to each bushel of wheat is about the
average. And according to this experiment, the carbonate of ammonia
produced over 200 lbs. of straw to a bushel of grain. How do you account
for this."
"It is a general rule," said I, "that the heavier the crop, the greater
is the proportion of straw to grain. On the no-manure plot, we have,
this year, 118 lbs. of straw to a bushel of dressed grain. Taking this
as the standard, you will find that the _increase_ from manures is
proportionally greater in straw than in grain. Thus in the increase of
barn-yard manure, this year, we have about 133 lbs. of straw to a bushel
of grain. I do not believe there is any manure that will give us a large
crop of grain without a still larger crop of straw. There is
considerable difference, in this respect, between different varieties of
wheat. Still, I like to see a good growth of straw."
"It is curious," said the Doctor, "that 3 cwt. of ammonia-salts alone on
plots 9 and 10 should produce as much wheat as was obtained from plot 2,
where 14 tons of barn-yard manure had been applied two years in
succession. I notice that on one plot, the ammonia-salts were applied at
once, in the spring, while on the other plot they were sown at four
different times--and that the former gave the best results."
The only conclusion to be drawn from this, is, that it is desirable to
apply the manure _early_ in the spring--or better still, in the autumn.
"You are a great advocate of Peruvian guano," said the Deacon, "
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