NE W YORK, SEPT. 24, 1881. 
[Entered according to Act of Congress, In the year tssi, by the Rural New-Yorker, in the office of the Librarian of Congress at Washington.] 
PRICE FIVE GENTS 
$2.00 PER YEAR 
farm (Topics, 
THE NITROGEN SUPPLY. 
J. B. LAWES, L. L. D., F. R. S. 
At Rothamsted, in the middle of May of 
the present year, I planted a few seeds of corn, 
which I had received from a gentleman living 
in Baltimore, upon that portion of my land 
which has grown a permanent wheat crop for 
40 years without the application of any ma- 
‘ nu re. 
In the adjoining field, which is un¬ 
der experiment with permanent barley, 
potatoes, and leguminous crops, I planted 
about 100 seeds, placing three together, and 
allowing them the space of a square yard or 
more from which to collect their food. 
The plot of ground upon which they were 
planted is outside the portion of the field under 
experiment; it certainly has received no dung 
for the last SO yeans, and may be described as a 
piece of waste land which has been plowed 
with the rest of the field, but has not been 
cropped, though vegetation has sprung up 
principally in the form of thistles or annual 
weeds. 
My object in sowing the com was a very 
irnple one. I wished to ascertain whether the 
and of a very dark rich green ; other plants, 
although growing and luxuriant, are much 
paler in color. In this field I have used 
mineral manures alone, and mineral manures 
with nitrates. 
In the same field, with the corn and close to 
it, there are 15 different sorts of leguminous 
crops growing ; they are all manured with (1) 
various mineral manures alone, and (2) with 
the same minerals, and in addition nitrates or 
salts of ammonia. 
Here we have no changes in the color of 
the plants due to the influence of the various 
manures ; there are none of those varieties of 
tint from a yellowish-green to a greenish-blue, 
which in the evening appears almost black, 
that we find in some of our graminaceous 
crops under experiment. A practiced eye 
might detect in some cases a brighter and 
more healthy green, but that is all. 
So far as the com is concerned, by a com¬ 
parison of the produce grown on the per¬ 
manently unmanured land, and that grown 
on the field supplied with minerals and 
nitrates or salts of ammonia, it is evident that 
the plant has profited largely by the applica¬ 
tion of the manures. At the same time, while 
I think that com, in common with the other 
cereal crops, is dependent upon a liberal sup¬ 
ply of nitric acid in the soil, I must not in 
saying this bo supposed to advocate itsapplica- 
Stewart’s view is that the poverty of his soil 
does not admit of so large a supply being 
welded. 
This question can only he set at rest by the 
continuous growth of corn under mineral 
manures alone ; and even under such circum¬ 
stances many years might elapse before satis¬ 
factory conclusions could be drawn. I have 
more than once, when writing upon American 
agriculture, pointed out the immense advant¬ 
age which United States farmers possess over 
ourselves and others who live in climates not 
suitable for the growth of cereal crops. 
It is quite true that the United States farmer 
is fully aware of this advantage, and does not 
requi re to have it pointed out by me; but, at the 
same time, I may possibly, by the aid of science, 
help him to understand why it is that he can 
grow a much larger crop of com, than he can 
of any of the other grain crops ; and, further, 
when his land is more or less exhausted, why 
mineral manures will be more effectual when 
applied to the corn than when applied to 
other grain crops. 
At Rothamsted we are now engaged iu writ¬ 
ing upon the subject of rain water and drain¬ 
age, and in the Journal of our Royal Agricul¬ 
tural Society, now being priuted, will be 
found an account of the composition of rain 
water passing through an uncropped soil. 
The article is well worth the study of those 
September was excessively wet, nearly six 
inches of rain having fallen, of which four 
inches passed through the soil. 
What was the result ? 
We find, by analysis of the drainage waters, 
that the nitrogen as nitric acid washed out 
of the soil, if calculated upon an area of an 
acre, would amount to 16 pounds, which is 
equal to the amount contained in 100 pounds 
of nitrate of soda, and not much less than 
what would be contained in 2,000 pounds of 
ripe corn as it stands in the field ! 
This formation of nitric acid has taken 
place upon a plot of the ordinary arable soil 
of my farm, which has been kept free from 
vegetation, and has been washed by the rain¬ 
fall for the last 10 years. 
If such a formation of nitric acid takes 
place in the Rothamsted soil during one short 
month, what must be the amount liberated in 
the United States soils in the interval be¬ 
tween the time when the wheat is ripe, and the 
time when the coni ceases to collect food from 
the soil. 
In these facte we have surely a very simple 
explanation of the reason why more benefit is 
derived from the application of mineral man¬ 
ures to com than to other grain crops. 
I abstain from entering upon any question 
with regard to the source of the nitrogen 
which we find in our drainage water, and will 
ENSILAGE 
WAGON.-Fig. 465. 
color of the plant under different foods cor¬ 
responded with that of the various cereal 
crops which we have under experiment. 
At the period at which 1 am writing—August 
22—the corn upon the unmanured wheat land 
is only one foot high ; there is no leaf that is 
one inch iu width, and the color is yellow, or 
a yellowish-green. 
In the adjoining field some of the plants are 
between four and five feet high, while the 
leaves are three-and-a-quarter inches wide, 
tion artificially. I quite agree with Mr. 
Stewart in thinking that mineral manures 
alone should be used, or mineral manures with 
the midition of a small quantity of nitrogen, 
so long as they enabled the farmer to grow 
UK) bushels of com or eveu a much smaller 
crop than that per acre. 
The only difference between Mr. Stewart and 
myself is this : I think that it is to the soil 
rather than to the atmosphere that we must 
look for the supply of nitrogen ; while Mr. 
who wish to know what is taking place in our 
soils ; but I will here refer only to one result, 
by way of illustrating my present subject. 
The month of July, 1S80, was exceedingly 
wet, and for the season of the year, an un¬ 
usual amount of water passed through our 
drain gauge soils. At the beginning of August 
the soils had lost the greater part of the nitric 
acid, 
August was a very dry montti and 
hardly any water passed through the soil ; 
merely point out that it could uot have been 
obtained from the atmosphere by plants, as 
the soil was kept free from vegetation. 
-♦ » » 
SILOS AND ENSILAGE WAGONS. 
PROFESSOR I. P. ROBERTS. 
The Silo. —After visiting Whitman & Bur- 
rel’s silo last Winter, I decided to build a smull 
one for experimental purposes. It is located 
in an angle just outside the bam, the base- 
