h may
often be used on these crops to great advantage.

I am inclined to think that considerable nitrate of soda will yet be
used in this country for manure. I do not suppose it will pay as a rule,
on wheat, corn and other standard grain crops. But the gardener, seed
grower, and nurseryman, will find out how to use it with great profit.
Our nurserymen say that they cannot use artificial manures with any
advantage. It is undoubtedly true that a dressing of superphosphate,
sown on a block of nursery trees, will do little good. It never reaches
the roots of the plants. Superphosphate can not be washed down deep into
the soil. Nitrate of soda is readily carried down, as deep as the water
sinks. For trees, therefore, it would seem desirable to apply the
superphosphate before they are planted, and plow it under. And the same
is true of potash; but nitrate of soda would be better applied as a
top-dressing every year, early in the spring.

The most discouraging fact, in Lawes' and Gilbert's experiments, is the
great loss of nitrogen. It would seem that, on an average, during the
last forty years, about one-half the nitrogen is washed out of the soil,
or otherwise lost. I can not but hope and believe that, at any rate in
this country, there is no such loss in practical agriculture. In Lawes'
and Gilbert's experiments on wheat, this grain is grown year after year,
on the same land. Forty annual crops have been removed. No clover is
sown with the wheat, and great pains are taken to keep the land clean.
The crop is hoed while growing, and the weeds are pulled out by hand.
The best wheat season during the forty years, was the year 1863. The
poorest, that of 1879; and it so happened, that after an absence of
thirty years, I was at Rothamsted during this poor year of 1879. The
first thing that struck me, in looking at the experimental wheat, was
the ragged appearance of the crop. My own wheat crop was being cut the
day I left home, July 15. Several men and boys were pulling weeds out
of the experimental wheat, two weeks later. Had the weeds been suffered
to grow, Sir John Bennet Lawes tells us, there would be less loss of
nitrogen. The loss of nitrogen in 1863, was about twenty-four pounds
per acre, and in 1879 fifty pounds per acre--the amount of available
nitrogen, applied in each year, being eighty-seven pounds per acre. As I
said before, the wheat in 1879 had to me a ragged look. It was thin on
the ground. There were not plants e