The kind and quantities of food needed to grow any vegetables is
found by an analysis of that vegetable. Having thus learned the
kind and quantity needed for any crop, the next step of the wise
farmer will be to ascertain what manures contain the necessary
constituents and which of these contain them in the cheapest form. A
little knowledge of Chemistry, in its application to manures, is of
incalculable value to the husbandman and no amount of experience and
traditionary knowledge can serve as a substitute for it. I believe
that it is in this direction that the great advance in agriculture
will be made, and were there no other argument for Agricultural
colleges the fact that they are prepared to give thorough instruction
in this one department would be a sufficient reason for their
existence, and for their liberal patronage by their several states.
Prof. Voelcker, an excellent authority in everything that pertains
to chemistry, in its application to agriculture, gives the following
table as the average composition of the ash of the principal root
crops.
+---------------------------------------------------------------------+
| AVERAGE COMPOSITION OF THE ASH OF ROOTS. |
+---------------------------------------------------------------------+
| |Number of Analyses. |
| | |Potash. |
| | | |Soda. |
| | | | |Lime. |
| | | | | |Magnesia. |
| | | | | | |Oxide of Iron. |
| | | | | | | |Phosphoric Acid. |
| | | | | | | | |Sulphuric Acid. |
| | | | | | | | | |Silica. |
| | | | | | | | | | |Chlorine.
+-------------+----+-----+-----+-----+----+----+-----+-----+----+-----+
| TURNIPS. | 38 | 49.8| 7.8| 11.7| 2.6| 0.9| 10.3| 11.8| 1.2| 5.0|
| SWEDES. | 7 | 38.9| 14.0| 12.8| 4.2| 0.8| 10.4| 13.7| 1.9| 4.2|
| MANGOLDS. | 12 | 46.6| 18.4| 5.9| 4.8| 0.8| 8.3| 3.7| 4.0| 9.9|
| SUGAR BEET. | 40 | 48.0| 10.4| 6.4| 9.5| 1.0| 14.4| 4.7| 3.8| 2.3|
| CARROTS. | 10 | 37.0| 20.7| 10.9| 5.2| 1.0| 11.2| 6.9| 2.0| 4.9|
| PARSNIPS. | 4 | 46.7| 2.7| 15.7| 6.0| 1.3| 15.8| 5.6| 2.4| 4.0|
+-------------+----+-----+-----+-----+----+----+-----+-----+----+-----+
| LEAF ASH. |
+-------------+----+-----+-----+-----+----+----+-----+-----+----+-----+
| TURNIPS. | 37 | 27.6| 5.1| 33.2| 2.6| 2.0| 7.3| 13.1| 3.5| 7.7|
| SWEDES. | 3 | 21.9| 12.3| 30.2| 3.2| 2.0| 6.4| 10.6| 4.8| 11.0|
| MANGOLDS. | 4 | 25.5| 23.3| 10.4| 9.7| 1.2| 5.4| 7.2| 3.3| 17.8|
| SUGAR BEET. | 7 | 21.9| 16.6| 19.5|18.1| 1.3| 7.3| 7.9| 3.1| 5.7|
| CARROTS. | 7 | 17.6| 18.2| 32.1| 3.9| 3.0| 3.8| 8.2| 5.2| 8.9|
+-------------+----+-----+-----+-----+----+----+-----+-----+----+-----+
This table shows us that the Mangolds require the mineral ingredients
of manure in the following order, when arranged with reference to
their importance:--Potash, Soda, Chlorine, Lime, Phosphoric Acid,
Magnesia, Sulphuric Acid, Silica. In addition to these minerals
other substances enter into the composition of Mangolds, the most
important of which is Nitrogen. Barn-yard manure contains about
all the elements needed by vegetation, but not always in the right
proportion, therefore, when applying it, it is always profitable to
know the proportions of the minerals which enter into crops that the
deficiency may be supplied from other sources. It is perhaps hardly
necessary to say that unleached wood ashes and the German Potash
Salts, Sulphate and Muriate, are the cheapest sources for Potash at
present known, while Soda and Chlorine are obtained from Muriate
of Potash or from the waste salt of the fisheries. Of this I shall
have more to say presently when treating of salt as an auxiliary
fertilizer. Lime is obtained from the common Carbonate of Lime of the
mason, either water or air slacked, and this usually contains more
or less of Magnesia, or from wood ashes which is largely one-third
lime. The great source of Phosphoric Acid is the bones of animals
or corprolites, by which is meant the fossilized bones and dung
of extinct animals; Sulphuric Acid is most cheaply obtained from
Plaster, which is Sulphate of Lime.
Some hold great benefit is derived by the crop of the following year,
from ploughing under the leaves as soon as the roots are topped; the
value of this is just what the analyses of our table shows. The large
crops reported as raised in this country, have been raised on soil
ranging from light to a friable clay loam and have received all the
way from eight to fifteen cords of barn-yard manure to the acre. In
some instances this has been all ploughed in; in others half spread
broadcast and ploughed in and the other half put in the furrows. When
coarse and unfermented I would advise a deep ploughing of it under,
in the Fall as with Carrots; other waste substances can be used as
substitutes for barn-yard manure, care being taken either that such
waste substances are specially rich in Potash, Soda and Chlorine, or
that these substances be added. The equivalents given are roughly
estimated under the article treating of the manure for Carrots
and will be sufficient for practical purposes; I therefore make
no further allusions to these cheap wastes as sources for manure,
further than to mention that sea manures are specially rich in potash
and soda.
Of all roots Mangolds are the rankest feeders, removing more plant
food from the soil than any other root crop. The crop of Mr. Albert
Fearing, of Hingham, Mass., was sixty tons of roots, and if the tops
were in the usual proportion, of about one-third, they weighed twenty
tons more, giving the enormous yield of eighty-tons of green food
from one acre of ground. The crop raised on Deer Island, in Boston
harbor, was about seventy tons to the acre; with a like proportion
of tops the total yield must have been over a hundred tons. In the
sewage farms of England eighty tons of roots have been raised on an
acre of ground. Fearing applied fifteen cords of manure to his acre
of ground; of the quantity applied to the Deer Island crop I regret I
have not the data at hand.
If the mere bulk alone was to be aimed at in the crop, the problem
would be a very simple one, but there are three points to be
considered: first, how to get a crop that shall be great in bulk
and at the same time give us the second desirable point, viz.:
_ripeness_, and thus insure the third desirable point, viz.: _the
highest percentage of sugar it is possible for the roots to acquire_.
This matter of the value of Mangolds, for feeding purposes, being in
about the same proportion as the sugar present, though appertaining
to that part of this Treatise which treats of “Feeding to Stock,”
yet has so direct a bearing on the manuring of the crops that I will
take it up at this place. The recent researches of that distinguished
chemist, Prof. Voelcker of England, than whom there is no better
authority, has thrown much light on the question of manure in its
application to this crop. The Professor takes the position that the
nutritious value of roots is in proportion to the amount of dry
matter in them, and that the percentage of sugar present coincides
with that of dry matter, the proportion of sugar rising or falling
with the percentage of dry matter in the roots. That the feeding
value does not depend on the proportion of nitrogen they contain, is
proved theoretically, by the fact that the percentage is very much
higher in the early stages of growth, before the crop is matured,
than it is later in the season, while in the experiments of Mr. Lawes
in feeding sheep, the lot containing the most nitrogen in the way of
nutrition gave the poorest results.
Assuming with Prof. Voelcker that bulk should not be sought at a
disproportionate sacrifice of sugar in the crop, and that certain
soils and certain manures and certain methods of cultivation are
more favorable than others to the development of this desirable
proportion. I present extracts from his valuable article on “Root
Crops as affected by Soil and Manures.”
“Land highly manured with rich dung from the fattening boxes or
stables, induces luxurious and vigorous growth in root crops, and,
as is well known, has a tendency to develop over-luxuriance in the
tops. This is the case more particularly if the dung is derived from
fattening beasts, liberally supplied with oil-cake and artificial
food, rich in nitrogenous constituents. If the Autumn turns out
fairly dry and warm, the roots in highly manured land continue to
grow vigorously, the bulbs swell to a large dimension, and if the
weather in September and October continues warm and dry, a heavy
weight, and fairly ripe roots, result from the liberal use of rich
dung. But should the Autumn be cold and wet, too liberal application
of good, well-rotten dung is apt to maintain the luxuriant tops in a
vigorous, active-growing condition, at a period of the year when the
crop has to be taken up, and the result is an immature root crop,
of a low feeding value. Although the bulbs may be of a good size,
they turn out, when grown under such conditions, watery, deficient
in sugar, and not nearly as nutritious as they would have been had
a more moderate dressing of dung been put upon the land. The main
cause of the immature condition and low-feeding quality of Mangolds
grown with an excessive quantity of rich dung is the comparatively
large amount of ammonial and nitrogenous constituents in the dung;
for numerous field experiments have shown that the peculiar tendency
of ammonia salts, and of readily available nitrogenous substances
is to induce luxuriant leaf-development and vigorous and prolonged
growth, which results frequently in a more or less immature condition
of the roots. There is thus danger of over-manuring crops; and the
desire to produce heavy crops of Mangolds not unfrequently leads
practical men not to appreciate sufficiently this danger. It is
quite true Mangolds are very greedy feeders, and no doubt some
soils will swallow up almost any amount of dung; but at the same
time it has to be borne in mind that all land is not alike, and
that there are many naturally rich clay loams containing immense
stores of plant food which requires only to be brought into play
by good cultivation in order to become available to plants. I am
much inclined to think that it is a mistake to manure soils of the
latter description too liberally with dung, even for Mangolds, and
that in many cases a more economical result, and certainly a better
quality of Mangolds, although not so heavy a crop, would be given,
if instead of all the enormous dressings of dung which are often
applied to that crop, the lands were manured in Autumn with only
half the quantity of dung, and the seed drilled in with three to
four cwt. of superphosphate or dissolved bones, which manures, as
we shall see presently have a tendency to produce early maturity in
roots. We frequently hear of complaints that Mangolds scour, or do
not keep well. Complaints of this kind are only expressions in other
words for the immature condition of the roots, and in many cases the
cause of this undesirable condition has to be sought in the excessive
amount of ammonial or nitrogenous constituents which are applied
to the Mangolds in the shape of heavy dressings of dung. The same
remarks apply with equal force to the exclusive and to abundant use
of sulphate of ammonia, nitrate of soda, and nitrogenous manures
in general. The special effect of all ammonial and nitrogenous
manures in general, as already stated, is to produce luxuriant leaf
development, to induce prolonged and vigorous growth, resulting in an
immature and watery condition of the bulbs.
“Large roots, generally speaking, are far less nutritious than
better matured roots of a moderate size. For illustration of this
fact I quote the following comparative analyses:
+-----------------------------------------------------------+
| |Water. |
| | |Nitrogenous Constituents. |
| | | |Sugar, Pectine, &c. |
| | | | |Crude Fibre. |
| | | | | | Ash. |
+----------------------+-------+------+-------+------+------+
| Mangolds 9 lbs. | 91.85 | 1.34 | 2.86 | 2.54 | 1.41 |
| “ 7½ lbs. | 89.48 | 1.24 | 3.95 | 4.51 | .82 |
| “ 4 lbs. | 89.77 | 0.73 | 7.68 | .89 | .93 |
| “ 1 to 2 lbs. | 86.90 | 0.61 | 10.51 | 1.07 | .91 |
+----------------------+-------+------+-------+------+------+
“Small Mangolds approach Sugar Beets in composition, whilst large
Sugar Beets are hardly better than common Mangolds, and monster beets
are even less nutritious than well-matured Mangolds of fair average
size. Monster roots, as is well known, are always very watery, poor
in sugar, and almost useless for feeding purposes.
“Big Berkshire beets,--one weighing 16 pounds and the other 12¼
pounds,--contained only 3.89 or 4 per cent. of sugar respectively,
and in round numbers as much as 91½ per cent. of water. This high
percentage of water is accompanied by a larger amount of albuminous
compounds and of mineral matter, than the proportions in roots,
containing very much more solid feeding matter. A large amount of
albuminous matter and of ash, indeed indicates immaturity and poverty
in sugar, a characteristic of big, excessively manured roots.
“Generally speaking, all nitrogenous manure, either should not be
used at all, or only sparingly, for roots, on stiffish land, and
all soils which contain a good deal of clay, are naturally cold and
unfavorable to a vigorous and rapid growth. Light land, like most
productive sandy soils and friable turnip loams, favors the quick
and vigorous growth of roots, and is conducive to early maturity.
“Nitrate of soda has the same general effect upon root crops as
nitrogenous manures, but it appears to be more energetic in its
action, and, on the whole, to be a useful addition to home manures,
and to increase the produce in roots more considerably than sulphate
of ammonia. Its effect is specially marked upon Mangolds, and, to my
knowledge, heavy crops of Mangolds have been produced upon rather
light land by 1 1-2 cwt. of Nitrate of Soda, two cwt. of common salt,
sown broadcast, and four cwt. of dissolved bones drilled in with the
seed.
“Potash salts in some field experiments which I have tried in
different parts of the country, have shown that Potash has a
decidedly beneficial effect upon root crops, on poor, sandy soils;
while on the majority of land, and notably upon clays or clay
loams, or soils in a good agricultural condition, Salts of Potash
do not increase the produce. The special effect of superphosphates,
dissolved bones and similar phosphatic manures, is to produce early
maturity; and hence phosphatic manures are employed in practice very
largely, and with much benefit, by root growers. In free-growing,
light soils, it is desirable either to use dissolved bones in
addition to half dressing of farm-yard manure, as a manure for roots,
or to spread broadcast 2 or 3 cwt. of salt, or 2 cwt. of guano and 1
cwt. of nitrate of soda and 2 cwt. of common salt, and to drill with
the seed 3 to 4 cwt. of dissolved bones. On the heavier description
of soils it is preferable to use mineral superphosphate for roots,
especially if the land has been dressed in Autumn with a moderate
quantity of dung.”