Organic Gardening Web
For Organic Gardeners to Share Knowledge

CHAPTER VI.

MANURES AND FERTILIZERS

To a very small extent garden vegetables get their food from the air.
The amount obtained in this way however, is so infinitesimal that from
the practical standpoint it need not be considered at all. Practically
speaking, your vegetables must get all their food from the garden soil.

This important garden fact may seem self-evident, but, if one may judge
by their practice, amateur gardeners very frequently fail to realize
it. The professional gardener must come to realize it for the simple
reason that if he does not he will go out of business. Without an
abundant supply of suitable food it is just as impossible to grow good
vegetables as it would be to train a winning football team on a diet of
sweet cider and angel cake. Without plenty of plant food, all the care,
coddling, coaxing, cultivating, spraying and worrying you may give will
avail little. The soil must be rich or the garden will be poor.

Plant food is of as many kinds, or, more accurately speaking, in as
many _forms_, as is food for human beings. But the first
distinction to make in plant foods is that between available and non-
available foods--that is, between foods which it is possible for the
plant to use, and those which must undergo a change of some sort before
the plant can take them up, assimilate them, and turn them into a
healthy growth of foliage, fruit or root. It is just as readily
possible for a plant to starve in a soil abounding in plant food, if
that food is not available, as it would be for you to go unnourished in
the midst of soups and tender meats if the latter were frozen solid.

Plants take all their nourishment in the form of soups, and very weak
ones at that. Plant food to be available must be soluble to the action
of the feeding root tubes; and unless it is available it might, as far
as the present benefiting of your garden is concerned, just as well not
be there at all. Plants take up their food through innumerable and
microscopic feeding rootlets, which possess the power of absorbing
moisture, and furnishing it, distributed by the plant juices, or sap,
to stem, branch, leaf, flower and fruit. There is one startling fact
which may help to fix these things in your memory: it takes from 300 to
500 pounds of water to furnish food for the building of one pound of
dry plant matter. You can see why plant food is not of much use unless
it is available; and it is not available unless it is soluble.


THE THEORY OF MANURING

The food of plants consists of chemical elements, or rather, of
numerous substances which contain these elements in greater or less
degrees. There is not room here to go into the interesting science of
this matter. It is evident, however, as we have already seen that the
plants must get their food from the soil, that there are but two
sources for such food: it must either be in the soil already, or we
must put it there. The practice of adding plant food to the soil is
what is called manuring.

The only three of the chemical elements mentioned which we need
consider are: nitrogen, phosphoric acid, and potash. The average soil
contains large amounts of all three, but they are for the most part in
forms which are not available and, therefore, to that extent, may be at
once dismissed from our consideration. (The non-available plant foods
already in the soil may be released or made available to some extent by
cultivation. See Chapter VII.) In practically every soil that has been
cultivated and cropped, in long-settled districts, the amounts of
nitrogen, phosphoric acid and potash which are immediately available
will be too meager to produce a good crop of vegetables. It becomes
absolutely necessary then, if one would have a really successful
garden, no matter how small it is, to add plant foods to the soil
abundantly. When you realize, (1) that the number of plant foods
containing the three essential elements is almost unlimited, (2) that
each contains them in different proportions and in differing degrees of
availability, (3) that the amount of the available elements already in
the soil varies greatly and is practically undeterminable, and (4) that
different plants, and even different varieties of the same plant, use
these elements in widely differing proportions; then you begin to
understand what a complex matter this question of manuring is and why
it is so much discussed and so little understood. What a labyrinth it
offers for any writer--to say nothing of the reader--to go astray in!

I have tried to present this matter clearly. If I have succeeded it may
have been only to make the reader hopelessly discouraged of ever
getting at anything definite in the question of enriching the soil. In
that case my advice would be that, for the time being, he forget all
about it. Fortunately, in the question of manuring, a little knowledge
is not often a dangerous thing. Fortunately, too, your plants do not
insist that you solve the food problem for them. Set a full table and
they will help themselves and take the right dishes. The only thing to
worry about is that of the three important foods mentioned (nitrogen,
phosphoric acid and potash) there will not be enough: for it has been
proved that when any one of these is exhausted the plant practically
stops growth; it will not continue to "fill up" on the other two. Of
course there is such a thing as going to extremes and wasting plant
foods, even if it does not, as a rule, hurt the plants. If, however,
the fertilizers and manures described in the following sections are
applied as directed, and as mentioned in Chapter VII., good results
will be certain, provided the seed, cultivation and season are right.


VARIOUS MANURES

The terms "manure" and "fertilizer" are used
somewhat ambiguously and interchangeably. Using the former term in a
broad sense--as meaning any substance containing available plant food
applied to the soil, we may say that manure is of two kinds: organic,
such as stable manure, or decayed vegetable matter; and inorganic, such
as potash salts, phosphatic rock and commercial mixed fertilizers. In a
general way the term "fertilizer" applies to these inorganic manures,
and I shall use it in this sense through the following text.

Between the organic manures, or "natural" manures as they are often
called, and fertilizers there is a very important difference which
should never be lost sight of. In theory, and as a chemical fact too, a
bag of fertilizer may contain twice the available plant food of a ton
of well rotted manure; but out of a hundred practical gardeners ninety-
nine--and probably one more--would prefer the manure. There is a reason
why--two reasons, even if not one of the hundred gardeners could give
them to you. First, natural manures have a decided physical effect upon
most soils (altogether aside from the plant food they contain); and
second, plants seem to have a preference as to the _form_ in which
their food elements are served to them. Fertilizers, on the other hand,
are valuable only for the plant food they contain, and sometimes have a
bad effect upon the physical condition of the soil.

When it comes right down to the practical question of what to put on
your garden patch to grow big crops, nothing has yet been discovered
that is better than the old reliable stand-by--well rotted, thoroughly
fined stable or barnyard manure. Heed those adjectives! We have already
seen that plant food which is not available might as well be, for our
immediate purposes, at the North Pole. The plant food in "green" or
fresh manure is not available, and does not become so until it is
released by the decay of the organic matters therein. Now the time
possible for growing a crop of garden vegetables is limited; in many
instances it is only sixty to ninety days. The plants want their food
ready at once; there is no time to be lost waiting for manure to rot in
the soil. That is a slow process--especially so in clayey or heavy
soils. So on your garden use only manure that is well rotted and broken
up. On the other hand, see that it has not "fire-fanged" or burned out,
as horse manure, if piled by itself and left, is very sure to do. If
you keep any animals of your own, see that the various sorts of manure
--excepting poultry manure, which is so rich that it is a good plan to
keep it for special purposes--are mixed together and kept in a compact,
built-up square heap, not a loose pyramidal pile. Keep it under cover
and where it cannot wash out. If you have a pig or so, your manure will
be greatly improved by the rooting, treading and mixing they will give
it. If not, the pile should be turned from bottom to top and outside in
and rebuilt, treading down firmly in the process, every month or two--
applying water, but not soaking, if it has dried out in the meantime.
Such manure will be worth two or three times as much, for garden
purposes, as that left to burn or remain in frozen lumps. If you have
to buy all your manure, get that which has been properly kept; and if
you are not familiar with the condition in which it should be, get a
disinterested gardener or farmer to select it for you. When possible,
it will pay you to procure manure several months before you want to use
it and work it over as suggested above. In buying manure keep in mind
not what animals made it, but what food was fed--that is the important
thing. For instance, the manure from highly-fed livery horses may be,
weight for weight, worth three to five times that from cattle wintered
over on poor hay, straw and a few roots.

There are other organic manures which it is sometimes possible for one
to procure, such as refuse brewery hops, fish scraps and sewage, but
they are as a rule out of the reach of, or objectionable for, the
purposes of the home gardener.

There are, however, numerous things constantly going to waste about the
small place, which should be converted into manure. Fallen leaves,
grass clippings, vegetable tops and roots, green weeds, garbage, house
slops, dish water, chip dirt from the wood-pile, shavings--any thing
that will rot away, should go into the compost heap. These should be
saved, under cover if possible, in a compact heap and kept moist (never
soaked) to help decomposition. To start the heap, gather up every
available substance and make it into a pile with a few wheelbarrows
full, or half a cartload, of fresh horse manure, treading the whole
down firmly. Fermentation and decomposition will be quickly started.
The heap should occasionally be forked over and restacked. Light
dressings of lime, mixed in at such times, will aid thorough
decomposition.

Wood ashes form another valuable manure which should be carefully
saved. Beside the plant food contained, they have a most excellent
effect upon the mechanical condition of almost every soil. Ashes should
not be put in the compost heap, because there are special uses for
them, such as dusting on squash or melon vines, or using on the onion
bed, which makes it desirable to keep them separate. Wood ashes may
frequently be bought for fifty cents a barrel, and at this price a few
barrels for the home garden will be a good investment.

Coal ashes contain practically no available plant food, but are well
worth saving to use on stiff soils, for paths, etc.


VALUE OF GREEN MANURING

Another source of organic manures, altogether too little appreciated,
is what is termed "green manuring"--the plowing under of growing crops
to enrich the land. Even in the home garden this system should be taken
advantage of whenever possible. In farm practice, clover is the most
valuable crop to use for this purpose, but on account of the length of
time necessary to grow it, it is useful for the vegetable garden only
when there is sufficient room to have clover growing on, say, one half-
acre plot, while the garden occupies, for two years, another half-acre;
and then changing the two about. This system will give an ideal garden
soil, especially where it is necessary to rely for the most part upon
chemical fertilizers.

There are, however, four crops valuable for green-manuring the garden,
even where the same spot must be occupied year after year: rye, field
corn, field peas (or cow peas in the south) and crimson clover. After
the first of September, sow every foot of garden ground cleared of its
last crop, with winter rye. Sow all ground cleared during August with
crimson clover and buckwheat, and mulch the clover with rough manure
after the buckwheat dies down. Sow field peas or corn on any spots that
would otherwise remain unoccupied six weeks or more. All these are sown
broadcast, on a freshly raked surface. Such a system will save a very
large amount of plant food which otherwise would be lost, will convert
unavailable plant food into available forms while you wait for the next
crop, and add _humus_ to the soil--concerning the importance of
which see Chapter VII.


CHEMICAL FERTILIZERS

I am half tempted to omit entirely any discussion of chemical
fertilizers: to give a list of them, tell how to apply them, and let
the why and wherefore go. It is, however, such an important subject,
and the home gardener will so frequently have to rely almost entirely
upon their use, that probably it will be best to explain the subject as
thoroughly as I can do it in very limited space. I shall try to give
the theory of scientific chemical manuring in one paragraph.

We have already seen that the soil contains within itself some
available plant food. We can determine by chemical analysis the exact
amounts of the various plant foods--nitrogen, phosphoric acid, potash,
etc.--which a crop of any vegetable will remove from the soil. The idea
in scientific chemical manuring is to add to the available plant foods
already in the soil just enough more to make the resulting amounts
equal to the quantities of the various elements used by the crop grown.
In other words:

)
Available plant food elements in (
the soil, plus > == Amounts of food elements
Available chemical food elements ( in matured crop
supplied in fertilizers )

That was the theory--a very pretty and profound one! The discoverers of
it imagined that all agriculture would be revolutionized; all farm and
garden practice reduced to an exact science; all older theories of
husbandry and tillage thrown by the heels together upon the scrap heap
of outworn things. Science was to solve at one fell swoop all the age-
old problems of agriculture. And the whole thing was all right in every
way but one--it didn't work. The unwelcome and obdurate fact remained
that a certain number of pounds of nitrogen, phosphoric acid and
potash--about thirty-three--in a ton of good manure would grow bigger
crops than would the same number of pounds of the same elements in a
bag of chemical fertilizer.

Nevertheless this theory, while it failed as the basis of an exact
agricultural science, has been developed into an invaluable guide for
using all manures, and especially concentrated chemical manures. And
the above facts, if I have presented them clearly, will assist the home
gardener in solving the fertilizer problems which he is sure to
encounter.


VARIOUS FERTILIZERS

What are termed the raw materials from which the universally known
"mixed fertilizers" are made up, are organic or inorganic substances
which contain nitrogen, phosphoric acid or potash in fairly definite
amounts.

Some of these can be used to advantage by themselves. Those practical
for use by the home gardener, I mention. The special uses to which they
are adapted will be mentioned in Part Two, under the vegetables for
which they are valuable.

GROUND BONE is rich in phosphate and lasts a long time; what is called
"raw bone" is the best "Bone dust" or "bone flour" is finely
pulverized; it will produce quick results, but does not last as long as
the coarser forms.

COTTON-SEED MEAL is one of the best nitrogenous fertilizers for garden
crops. It is safer than nitrate of soda in the hands of the
inexperienced gardener, and decays very quickly in the soil.

PERUVIAN GUANO, in the pure form, is now practically out of the market.
Lower grades, less rich in nitrogen especially, are to be had; and also
"fortified" guano, in which chemicals are added to increase the content
of nitrogen. It is good for quick results.

NITRATE OF SODA, when properly handled, frequently produces wonderful
results in the garden, particularly upon quick-growing crops. It is the
richest in nitrogen of any chemical generally used, and a great
stimulant to plant growth. When used alone it is safest to mix with an
equal bulk of light dirt or some other filler. If applied pure, be sure
to observe the following rules or you may burn your plants: (1)
Pulverize all lumps; (2) see that none of it lodges upon the foliage;
(3) never apply when there is moisture upon the plants; (4) apply in
many small doses--say 10 to 20 pounds at a time for 50 x 100 feet of
garden. It should be put on so sparingly as to be barely visible; but
its presence will soon be denoted by the moist spot, looking like a big
rain drop, which each particle of it makes in the dry soil. Nitrate of
soda may also be used safely in solution, at the rate of 1 pound to 12
gallons of water. I describe its use thus at length because I consider
it the most valuable single chemical which the gardener has at command.

MURIATE and SULPHATE OF POTASH are also used by themselves as sources
of potash, but as a general thing it will be best to use them in
combination with other chemicals as described under "Home Mixing."

LIME will be of benefit to most soils. It acts largely as an indirect
fertilizer, helping to release other food elements already in the soil,
but in non-available forms. It should be applied once in three to five
years, at the rate of 75 to 100 bushels per acre, after plowing, and
thoroughly harrowed in. Apply as long before planting as possible, or
in the fall.


MIXED FERTILIZERS

Mixed fertilizers are of innumerable brands, and for sale everywhere.
It is little use to pay attention to the claims made for them. Even
where the analysis is guaranteed, the ordinary gardener has no way of
knowing that the contents of his few bags are what they are labeled.
The best you can do, however, is to buy on the basis of analysis, not
of price per ton--usually the more you pay per bag, the cheaper you are
really buying your actual plant food. Send to the Experiment Station in
your State and ask for the last bulletin on fertilizer values. It will
give a list of the brands sold throughout the State, the retail price
per ton, and the actual value of plant foods contained in a ton. Then
buy the brand in which you will apparently get the greatest value.

For garden crops the mixed fertilizer you use should contain (about):

)
Nitrogen, 4 per cent. ( Basic formula
Phosphoric acid, 8 per cent. > == for
Potash, 10 per cent. ( Garden crops
)

If applied alone, use at the rate of 1000 to 1500 pounds per acre. If
with manure, less, in proportion to the amount of the latter used.

By "basic formula" (see above) is meant one which contains the plant
foods in the proportion which all garden crops must have. Particular
crops may need additional amounts of one or more of the three elements,
in order to attain their maximum growth. Such extra feeding is usually
supplied by top dressings, during the season of growth. The extra food
beneficial to the different vegetables will be mentioned in the
cultural directions in Part Two.


HOME MIXING

If you look over the Experiment Station report mentioned above, you
will notice that what are called "home mixtures" almost invariably show
a higher value compared to the cost than any regular brand. In some
cases the difference is fifty per cent. This means that you can buy the
raw chemicals and make up your own mixtures cheaper than you can buy
mixed fertilizers. More than that, it means you will have purer
mixtures. More than that, it means you will have on hand the materials
for giving your crops the special feeding mentioned above. The idea
widely prevails, thanks largely to the fertilizer companies, that home
mixing cannot be practically done, especially upon a small scale. From
both information and personal experience I know the contrary to be the
case. With a tight floor or platform, a square-pointed shovel and a
coarse wire screen, there is absolutely nothing impractical about it.
The important thing is to see that all ingredients are evenly and
thoroughly mixed. A scale for weighing will also be a convenience.
Further information may be had from the firms which sell raw materials,
or from your Experiment Station.


APPLYING MANURES

The matter of properly applying manure, even on the small garden, is
also of importance. In amount, from fifteen to twenty-five cords, or 60
to 100 cartloads, will not be too much; although if fertilizers are
used to help out, the manure may be decreased in proportion. If
possible, take it from the heap in which it has been rotting, and
spread evenly over the soil immediately before plowing. If actively
fermenting, it will lose by being exposed to wind and sun. If green, or
in cold weather, it may be spread and left until plowing is done. When
plowing, it should be completely covered under, or it will give all
kinds of trouble in sowing and cultivating.

Fertilizers should be applied, where used to supplement manure or in
place of it, at from 500 to 1500 pounds per acre, according to grade
and other conditions. It is sown on broadcast, after plowing, care
being taken to get it evenly distributed. This may be assured by sowing
half while going across the piece, and the other half while going
lengthwise of it. When used as a starter, or for top dressings--as
mentioned in connection with the basic formula--it may be put in the
hill or row at time of planting, or applied on the surface and worked
in during the growth of the plants. In either case, especially with
highly concentrated chemicals, care must be taken to mix them
thoroughly with the soil and to avoid burning the tender roots.

This chapter is longer than I wanted to make it, but the problem of how
best to enrich the soil is the most difficult one in the whole business
of gardening, and the degree of your success in growing vegetables will
be measured pretty much by the extent to which you master it. You
cannot do it at one reading. Re-read this chapter, and when you
understand the several subjects mentioned, in the brief way which
limited space made necessary, pursue them farther in one of the several
comprehensive books on the subject. It will well repay all the time you
spend upon it. Because, from necessity, there has been so much of
theory mixed up with the practical in this chapter, I shall very
briefly recapitulate the directions for just what to do, in order that
the subject of manuring may be left upon the same practical basis
governing the rest of the book.

To make your garden rich enough to grow big crops, buy the most
thoroughly worked over and decomposed manure you can find. If it is
from grain-fed animals, and if pigs have run on it, it will be better
yet. If possible, buy enough to put on at the rate of about twenty
cords to the acre; if not, supplement the manure, which should be
plowed under, with 500 to 1500 pounds of high-grade mixed fertilizer
(analyzing nitrogen four per cent., phosphoric acid eight per cent.,
potash ten per cent.)--the quantity in proportion to the amount of
manure used, and spread on broadcast after plowing and thoroughly
harrowed in. In addition to this general enrichment of the soil,
suitable quantities of nitrate of soda, for nitrogen; bone dust (or
acid phosphate), for phosphoric acid; and sulphate of potash, for
potash, should be bought for later dressings, as suggested in cultural
directions for the various crops.

If the instructions in the above paragraph are followed out you may
rest assured that your vegetables will not want for plant food and
that, if other conditions are favorable, you will have maximum crops.