The Portland daily press. [volume] (Portland, Me.) 1862-1921, 1882-04-07
Soil analysis.

Professor E. w. Hilgard, writing on the
objects and interpretations of soil analysis in
the Journal of Science, accepts as correct the
principle that other things being equal, pro-
ductiveness is or should be sensibly proper
toned to the amount of available plant-food
within reach of the roots during the period
of the plants development, provided that
such supply does not exceed the maximum
of that which the plant can utilize when the
surplus supply remains inert 10 lind the
exact value of the soil from analysis it is nee
essary therefore not so much to discover the
actual amounts of the constituents in the
soil as to find the amounts which are acces-
sible to and assimilated by the plants. The
problem becomes then to find solvent that
shall as nearly as possible represent the ac-
ton of the plant itself.
Professor Hilgard's method of analysis
starts from the observation of the productive
qualities of the soil as indicated by the ma
| tive growth. Next, he endeavors to ascer-
| tain the peculiarities of the soil that form
| this sort of growth as distinguished from
| other growths on other soils. Mechanical
| conditions, it appears, must always be taken
| into account. As rule soil exhibiting a
| high percentage of plant-food is fertile, but
| soil having low percentage is not, on the
| other hand, necessarily poor A loose soil,
| by enlarging the sphere of expansion OF the
| roots, may enable them to reach as large
quantities of food more widely scattered as
| they can find in highly charged but more
| compact and less penetrable soil.
The evidence from the analysis so far
| ins,itut ed is unquestionable in regard to the
present productiveness of soil being mesu-
| rably dependent on the presence of certain
| minim UNI quantity of lime. After the
presence of lime the proportion of phos'
| phoric acid appears to be The most impor-
to,t footor In fbo nroduativanace of soile
A certain percentage of potash is required,
but it is present in most soils. Professor
Hilgard infers, asa rale, that potash man
ures are among the first to be sought for
after the soils have become exhausted. Iron
in the shape of ferric hydrate finely diffused
appears to be an important ingredient,
valuable on account of its chemical qualities.
1t has highly absorptive power for gases,
and soils in which it occurs resist drought
better than Others; and the universal prefer
ence given by farmers to red lands shows
the results of experience in this respect.
The efficacy of the hydrate depends upon
the state of fine division; and when merely
incrusting the sand grains or aggregated
into bogore grsins itexerts little or no infu-
ence, although analysis may show high
percentage. On tina other hand, ferruginous
soils are the first liable to damage from i'm
perfect drainage, overfows and the like.
Sowing In the Shade.
Thomas Meehan, in his seed catalogue,
just published, says that most failures with
seed arise from not sowing in partial shade.
If the hot sun bursts upon the seed beds
while the seeds are swelling, and cold fol-
lows, many may rot before the plants reach
the surface. For large quantities, artificial
arbors, tall enough to work under, are en-
ployed. For smaller quantities, brushwood,
or the thin shade of cornstalks, or of skel-
eton frame, answers we'll Lattice frames
NAV be employed to exclude birds. Many
kinds of seeds, with experienced persons,
do not require shade; but for others, shade
is always recommended. Very early sowing
is important With seeds which do not
grow till the second season, the ground
should be kept clean and shaded the summer
through. These hints will do to remem-
Der for next springs operations.