ARTIFICIAL MANURES AND THEIR APPLICATION TO GARDEN CROPS

Plants, like animals, require food for their sustenance and development,

and when this is administered in insufficient quantities, or unsuitable

foods are supplied, they remain small, starved, and unhealthy.



The chemical elements composing the natural food of ordinary crops are

ten in number, viz.--carbon, hydrogen, oxygen, nitrogen, sulphur,

phosphorus, potassium, calcium, magnesium, and iron. These are obtained

from the soil and air, and unless all of them are available plants will

not grow. The absence of even one of them is as disastrous as the want

of all, and a deficiency of one cannot be made up by an excess of

another; for example, if the soil is deficient in potassium the crop

suffers and cannot be improved by adding iron or magnesium. All the

food-elements are found in adequate quantities in practically all soils

and the surrounding air, except three--nitrogen, potassium, and

phosphorus. These are often present in reduced amount, or in a state

unsuited to plants; in such cases the deficiency must be made up before

remunerative healthy crops can be grown, and it is with this express

object that manures are added to the soil.



One of the best known substances employed in this way is farmyard

manure, which is indirectly derived from plants and contains all the

elements needed for the growth of crops. It is, however, of very

variable composition and rarely, or never, contains these elements in

the most suitable proportions, and its value can always be greatly

improved by supplementing its action with one or other of the so-called

artificial manures or fertilisers. Although it is strongly advisable to

add farmyard manure or vegetable composts to the soil of all gardens now

and again, in order to keep the texture of the soil in a satisfactory

condition, excellent crops can be grown by the use of artificial

fertilisers alone. To obtain the best results from these some experience

is of course necessary, but the following details regarding the nature

and application of the commoner and more useful kinds should prove a

serviceable guide in the majority of cases.



Artificial manures may be divided into three classes:--



1. The Nitrogenous class, of which nitrate of soda and sulphate of

ammonia are examples.



2. The Phosphatic class, such as superphosphate, basic slag, and steamed

bone flour.



3. The Potash class, including kainit and sulphate of potash. The

several examples of each class contain only one of the three important

plant food-elements, and as a single element can only be of use when the

others are present in the soil, it is generally advisable to apply one

from each class, either separately or mixed, in order to insure that the

crop is supplied with nitrogen, phosphates, and potash.



Nitrogenous manures specially stimulate the growth of the foliage,

stems, and roots of plants, and are therefore of the greatest benefit to

Carrots, Parsnips, Turnips, Beet, Celery, Asparagus, Rhubarb, all the

Cabbage tribe, and leafy crops generally.



Nitrate of soda supplies the single plant food-element, nitrogen, and

the soda for all practical purposes may be disregarded. It dissolves

very easily in water and is taken up immediately by growing plants, its

effect being plainly seen a few days after application. As this

artificial readily drains away from uncropped land it should only be

administered to growing plants. It is best applied in spring and summer

and in small quantities; for example, at the rate of one pound per

square rod, repeated at intervals of two or three weeks, rather than in

a single large dose. Nitrate of soda must not be mixed with

superphosphate, but it may be added to basic slag and the potash

manures.



Sulphate of ammonia is another nitrogenous fertiliser, similar in its

effects to nitrate of soda, but slower in action since its nitrogen must

undergo a change into nitrate before it is available for plants. It is

held by the soil, and can therefore be applied earlier in spring than

nitrate of soda without fear of loss. The continued use of this manure,

however, is liable to make the soil sour, and consequently it should

only be employed on ground containing lime, or to which lime has been

added. Never mix sulphate of ammonia with basic slag or with lime, but

it may be mixed with superphosphate and the potash manures.



Phosphatic manures have the opposite effect to the nitrogenous

fertilisers, checking rampant growth and encouraging the early

formation of flowers, fruit, and seeds. They are comparatively

inexpensive and should be liberally applied to all soils for all crops.

Superphosphate is an acid manure and best suited for use on soils

containing lime. Basic slag is a better material for ground deficient

in lime, or where 'club-root' is prevalent. It is less soluble and

therefore slower in action than superphosphate. Both these fertilisers

should be dug into the soil some time before the crop is planted or seed

sown--superphosphate at the rate of two to three pounds per square rod;

basic slag in larger amount, five to six pounds per square rod.

Superphosphate may also be employed as a top-dressing and worked into

the surface around growing plants with the hoe. Steamed bone meal or

flour is another useful phosphatic fertiliser, valuable on the lighter

classes of soil.



Potash manures are of benefit to plants in all stages of growth. They

are particularly valuable to Potatoes, leguminous crops, Carrots,

Parsnips, Turnips, and Beet. Like the phosphatic manures they should be

worked into the soil before seeds are sown or plants are put out.

Kainit is best applied in autumn, for it contains a considerable

amount of common salt and magnesium compounds which are sometimes

deleterious and best washed away in the drainage water during winter. It

should be dug in at the rate of about three pounds per square rod.

Sulphate of potash is three or four times as rich in potash as kainit,

and is correspondingly more expensive; apply in spring and summer, a

little in advance of sowing or planting, at the rate of about one pound

per square rod.



Lime.--- A word or two must be said about lime, which is a natural

constituent of all soils. In many instances there is sufficient for the

needs of most plants, but where lime is deficient in quantity it must be

added before healthy crops can be raised. Old gardens to which dung has

been freely applied annually require a liberal dressing of lime every

few years, or the ground becomes sour and incapable of growing good

crops of any kind. To insure the proper action of whatever manures are

used and to secure healthy crops, an application of slaked quicklime, at

the rate of fourteen to twenty pounds per square rod, is strongly

recommended. As a remedy against 'clubbing' or 'finger-and-toe' disease

of the Cabbage tribe of plants it is indispensable; it also neutralises

the baneful acidity of the land, and opens up stiff soils, making them

more easily tilled, more readily penetrated by the air, and warmer by

the better drainage of water through them.



The following suggestions for the manuring of the different crops

mentioned will be found effective. It is, however, not intended that

they should be slavishly followed, for useful substitutions may be made

in the formulae given, if the nature of the various fertilisers is

understood and an intelligent grasp is obtained of the principles of

manuring enunciated in this and the preceding chapter.



In place of nitrate of soda, a similar quantity of sulphate of ammonia

may be used.



Instead of superphosphate, the following may be advantageously employed:

phosphatic guano, or mixtures of basic slag and superphosphate, or bone

meal and superphosphate; or basic slag may be applied alone on land

deficient in lime.



Four pounds of kainit may also take the place of one pound of sulphate

of potash in the suggested mixtures mentioned below.



Where dung is recommended, twenty to twenty-five loads per acre is

meant; larger quantities are frequently applied, but these are

uneconomical and much less efficient than more moderate amounts

supplemented with artificial fertilisers.



All the manures should be worked into the soil before sowing or planting

out, except the nitrate of soda, which is best applied separately to the

growing plants, preferably in small doses at intervals of two to four

weeks.



In all cases the quantities of artificials named are intended for use

on one square rod or pole of ground.



PEAS AND BEANS.--These leguminous plants are able to obtain all the

nitrogen they need from the air. They should, however, be amply supplied

with potash and phosphates, a good dressing being:--



2-3/4 to 3-1/2 lb. superphosphate

3/4 lb. sulphate of potash



DWARF BEANS are sometimes benefited by the addition of 1/2-lb. to 1 lb.

of nitrate of soda.