onia gave an increase
of about 20 bushels per acre, and the same quantity of nitrogen in
nitrate of soda an increase of 26 bushels per acre.

The next year, the season seems to have been a very unfavorable one for
oats. The no-manure plot produced less than 17 bushels per acre; and the
"ashes" and superphosphate on plot 2, give an increase of less than 3
bushels per acre. But it will be seen that on plot 3 the ammonia-salts
do as much good in this unfavorable season as in the favorable one. They
give an increase of over 20 bushels per acre.

"A few such facts as this," said the Deacon, "would almost persuade me
that you are right in contending that it is in the unfavorable seasons,
when prices are sure to be high in this country, that a good farmer
stands the best chance to make money."

"Where mixed alkalies and superphosphate," said the Doctor, "are added
to the ammonia, the increase _from the ammonia_ is far greater than
where ammonia is used alone. In other words, by comparing plot 2 and
plot 4, you will see that the ammonia gives an increase of 30-1/4
bushels per acre in 1869, and 31-1/2 bushels in 1870."

The truth of the matter probably is this: 100 lbs. of available ammonia
per acre is an excessive supply, when used alone. And in fact Mr. Lawes
himself only recommends about half this quantity.

Whether it will pay us to use artificial manures on oats depends on the
price we are likely to get for the oats. When the price of oats _per
lb._ and oat-straw is as high as barley and barley-straw _per lb._, then
it will pay a _little better_ to use manure on oats than on barley. As a
rule in this country, however, good barley is worth more per lb. than
good oats; and it will usually pay better to use artificial manures on
barley than on oats.

Some years ago Mr. Bath, of Virginia, made some experiments on oats with
the following results:
Bushels of oats
per acre.
No. 1--200 lbs. Superphosphate 22
No. 2--200 lbs. Peruvian guano 48-3/4
No. 3--100 lbs. Peruvian guano 32

The oats were sown March 13, and the crop harvested July 4.

In 1860, I made some experiments with gypsum, superphosphate, and
sulphate of ammonia as a top-dressing on oats.

The land was a clover-sod, plowed about the middle of May, and the oats
sown May 20. On the 26th of May, just as the oats were coming up, the
manures were sown broadcast. The