-----
| |Air-dry |Nitrogen |Phosphoric
| |roots, |in roots,|acid in
| |per acre.|per acre.|roots,
| | | |per acre.
------+--------------------------------+---------+---------+----------
|1st Year. | | |
No. 1.| Good Clover from brow | 7705 | 100 |
| of the hill | | |
" 2.| Bad " " " | 3920 | 31 |
| " " " | | |
| | | |
|2d Year. | | |
" 3.| Good Clover from bottom | 7569 | 61 | 27
| of the field | | |
" 4.| Thin " " brow | 8064 | 66 |
| " " hill | | |
| | | |
" 5.|Heavy crop of first-year clover | | |
| mown twice for hay | | 24-1/2 |
" 6.|Heavy crop of first-year clover | | |
| mown once for hay, | | 51-1/2 |
| and then for seed | | |
" 7.|German experiment, | | |
| 10-1/4 inches deep | 8921 | 191-1/2 | 74-3/4
------+--------------------------------+---------+---------+----------

I have not much confidence in experiments of this kind. It is so easy to
make a little mistake; and when you take only a square foot of land, as
was the case with Nos. 5 and 6, the mistake is multiplied by 43,560.
Still, I give the table for what it is worth.

Nos. 1 and 2 are from a one-year-old crop of clover. The field was a
calcareous clay soil. It was somewhat hilly; or, perhaps, what we here,
in Western New York, should call "rolling land." The soil on the brow of
the hill, "was very stony at a depth of four inches, so that it could
only with difficulty be excavated to six inches, when the bare
limestone-rock made its appearance."

A square yard was selected on this shallow soil, where the clover was
good; and the roots, air-dried, weighed at the rate of 7,705 lbs. per
acre, and contained 100 lbs