580 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
[ December J5, 1884. 
in the various parfcg of a fairy ring has been ascertained in the case of 
several rings at Eothamsted {Trans. Chem, Soc., 1883, 208). The amount of 
carbon destroyed during the progress of the ring of fungus is very con¬ 
siderable. The difference between the amounts of carbon found in the soil 
outside the ring, where the fungus has not yet appeared, and within the 
ring, where the action of the fungus is completed, represents indeed a loss 
of something like tOOO lbs. of carbon per acre. 
Neither the animal life of the soil, nor the fungi, carry their oxidation 
of nitrogenous matter to such a point that ammonia or nitric acid is pro¬ 
duced. These two agents perform some of the rough work of oxidation, but 
do not bring the nitrogen into the condition most suitable for plant-food. 
This object is accomplished by the bacteria, the third of the principal 
oxidising agents within the soiL The bacteria of soil have been as yet but 
slightly studied; but such organisms undoubtedly exist in great numbers, 
and of many kinds and functions. 
It may be taken as a general rule that in the absence of oxygen bacteria 
act as ferments, splitting up the organic matter into new compounds, while 
in the presence of oxygen they become active oxidising agents. In the case 
of many bacteria the nitrogen of the organic matter attacked is reduced to 
the form of ammonia, and under some conditions it may be partially evolved 
as free nitrogen. The nitrifying organism forms apparently a class by 
itself, it alone producing nitric acid. We do not yet know with certainty 
what nitrogenous bodies are capable of direct conversion into nitric acid. 
Albuminoids, amides (asparagine and urea) and ammonia can, indeed, 
readily be nitrified, but the first stage of the action on albuminoids and 
amides is apparently the production of ammonia, and we cannot yet say if 
the action of the special nitrifying organism begins at the ammonia or 
extends to the earlier stages of the action. If ammonia alone is attacked by 
the nitrifpng organism, we must then regard the other associated bacteria 
as executing the preliminary portion of the work. 
We will now glance at the influence which external conditions exert 
on the action of the various agents just mentioned. One essential condition 
for processes of oxidation is, of course, the presence of oxygen : an open, 
porous soil is thus far more exposed to oxidation than one in a closely con¬ 
solidated condition ; the effect of tillage is consequently greatly to promote 
oxidation. Water is also essential for the activity of all living agents ; 
oxidation is thus far more rapid in a moist soil than in a dry one. A great 
excess of water is, however, fatal to oxidation, air being naturally excluded 
as soon as the soil is filled with water. Temperature is another prime 
factor in determining the rate of oxidation in soil ; the activity of all living 
agents, whether vegetable or animal, being dependent on the occurrence of 
a favourable degree of heat, and being confined to certain specific ranges of 
temperature. Oxidation is consequently far more rapid in summer than in 
winter, and much more energetic in hot climates than in cold. A fuithtr 
condition very favourable to oxidation is the presence of some base in the 
soil capable of neutralising the acids that are produced. Without the pre¬ 
sence of such a base no formation of nitric acid will occur. This part is 
generally played by the carbonate of calcium commonly present in soils. 
Liming, of course, will act in the same direction. 
We are now probably in a position to understand what is the cause of the 
enormous differences between different soils, as to the quantity of organic 
matter and of nitrogen which they contain. 
In a peat bog we find the conditions most favourable for the accumula¬ 
tion of organic matter. The sphagnum and other bog plants cover the bog 
with a perennial grow'th, which supplies annually a large residue of dead 
vegetable matter ; while the soil, being waterlogged, and necessarily free 
from carbonate of calcium, the oxidation of this vegetable residue is reduced 
to a minimum. Peat bogs also usually occur in cool climates. 
In fertile meadow land we have conditions much more favourable to 
oxidation. The soil here is not waterlogged, but fairly w'ell aerated, and 
oxidising agents, both animal and vegetable, are abundantly present. The 
land being, however, always covered by a thick vegetable growth, con¬ 
siderable accumulations of organic matter may take place in the soil, though 
never to the extent observed in a peat bog. 
When we next turn to arable land we find that the conditions have 
become so favourable to oxidation that loss rather than gain of soil nitrogen 
is probably the general rule. Oxidation is here greatly assisted by the 
operations of tillage, and by the fact that the land lies in a state of fallow 
during a considerable part of most years. In such soils large quantities of 
nitric acid are produced, which may be washed out by winter rains and lost. 
At_Eothamsted the old pasture land contains in the first 9 inches nearly 
twice as much nitrogen and more than twice as much carbon as the arable 
land to the same depth. As all arable land was once pasture or woodland, 
the loss that has occurred during cultivation is obvious. 
It is quite clear from what has now been stated that arable culture 
affo'ds great opportunities for serious loss of soil nitrogen, and from this 
point of view arable culture may be said to present considerable dis¬ 
advantages as compared with pasture. But there is another side to the 
question. The rapid oxidation of organic matter which occurs under 
tillage means the production of a large amount of available plant-food. 
The nitrates produced, though liable to be lost by drainage, are also equally 
capable of producing valuable crops, and the skill of the farmer is displayed 
in so arranging his methods of culture that the nitrates shall be a source of 
profit instead of loss. The effect of free oxidation on the productiveness of 
land is, indeed, strikingly shown by the fact that arable land, though con¬ 
taining only half the amount of nitrogen that is found in pasture, is, never¬ 
theless, capable of yielding a greater weight of annual produce per acre. 
EEUIT FOECING. 
Peaches and Necatarines.— Early Forced House. —The buds of 
these trees are swelling freely, and 45° should be the minimum tempera¬ 
ture on cold nights, and between that and 60° is ample even on mild 
nights, with a rise of 10° to 15° by day from sun heat. Nothing is gained by 
undue haste until we have increased light and length of days. Peach blooms 
allowed to unfold in a low temperature, particularly at night, with free 
ventilation, always set and stone well. They will thus ripen good crops 
of fruit in a higer temperature, by which means time lost at the outset is 
redeemed, the trees make strong short-jointed wood, and if due attention 
is paid to thinning one fruit to every square foot of trellis covered with 
foliage, they will long remain profitable trees. Large crops of Peaches 
are only the forerunner of dissaster, as Peach trees, like other fruit trees, 
are only capable of maturing a given weight of fruit, and if overcropped 
they do not exceed that weight in the aggregate, consequently the extra 
quantity is obtained at the expense of size and quality. Cease syringing 
as soon as the flowers open, but maintain a genial condition of the 
atmosphere by damping in the morning and afternoon of fine days. Kaise 
the temperature early in the day to 50°, and not exceeding 55° from fire 
heat, and admit a little air, yet not to lower the temperature below 50°, 
and increase the ventilation with the sun heat, having it full at 65°, and 
gradually reduce it with the declining heat, closing for the day at 55°. 
A little ventilation should be provided constantly at the top of the house. 
Houses toRijien Fruit in Early June .—Where there are three or more 
Peach houses annually forced, the second should be ready for closing 
January 1st. If the house has been open so as to receive the autumnal 
rains the borders may be in good condition—that is, thoroughly moist to 
the drainage, but if there is any doubt about this an examination should 
be made, and if necessary repeated soakings given so as to thoroughly 
moisten the soil in every part, and if the trees are weakly liquid manure 
may be given. It has been a prevailing practice to allow the inside 
borders to become dry through the autumn and early winter months, but 
it is a mistake that is often followed by the buds falling—the most prc - 
minent flower buds, and the disaster is frequently attributed to every 
cause but the right one. With the borders of suitable material resting 
on ample drainage, there is little danger of their receiving too much 
water either by exposing them to the autumn rains or by giving liberal 
supplies of rain water from the tanks. Fire heat will only be necessary 
during the first fortnight to raise the temperature by day to 50°, at which 
open, and close the house, and to prevent its falling below 40° at night, 
and it ought not to exceed 45° at night, except it be from natural means. 
Syringe the trees twice a day, morning and afternoon, the latter sufficiently 
early to allow the trees to become fairly dry before nigh*^. 
Cucumbers. —Take every opportunity to encourage growth in the plants 
by closing the house early on bright days, and damp the pathways and 
plants with tepid water, us'ng a fine-rose syringe for the latter. Tepid 
liquid manure in a weak state must be given to plants which are making 
free growth. A beneficial and invigorating influence will be given the 
plants by a top-dressing to the bed of a compost composed of two parts 
turfy loam, one part fibrous peat, and one part horse droppings, thoroughly 
mixed and warmed to the temperature of the house by being taken in some 
time previously. If the plants are only growing weakly it will be well to 
ease them of fruit, and to withhold liquid manure until they show signs 
of free growth. 
Manure Beds .—Fermenting material having been mixed and turned 
to allow of the rank heat escaping, it will be ready for making into a 
hotbed, which should be done on a southern aspect, and in front of a 
wall or hedge, so as to break the north wind. The site should also be 
higher than the surrounding level, or if damp and low a layer of faggots 
placed where the bed is to be made will keep it dry. Let the bed be 
made sufficiently large to take the frame, and be a few iaefips larger 
than the frame all around. As the bed is made beat it down firmly and 
even with the back of the fork, and sufficiently high to allow for shrink¬ 
ing ; and as this will be fully one-third, hence the bed will need to be 
about 4 feet high in front and 6 feet at the back. If some 3-inch drain 
tdes are at hand place them on the manure across the bed end to end 
right across, so as to form drains about 18 inches apart, or a few pea 
sticks may be placed across and along the bed for the purpose of prevent¬ 
ing overheating. This is a good old plan too much neglected. For early 
work, too, it is a good plan to have the inside of the frame lined with ha’f- 
inch boards to within 6 inches of the top, and down to the bottom, with 
an inch cavity between it and the frame ; and this is a ready means 
of admitting top heat instead of its being absorbed by the plunging 
material through the sides of the frame. JPlace sufficient fermenting 
material in the frame to make the back level with the front, then 2 or 
3 inches depth of dry leaves, and 4 to 6 inches of dry sawdust, and as 
soon as the heat is developed it will be ready fur Cucumber and Melon 
seeds, and will also be extremely useful for cuttings. 
Strawberries in Pots. —The Strawberry is very impatient of forcing 
in its early stages and until the fruit is fairly swelling, therefore caution at 
this time is absolutely essential. In frosty or dull weather it is well to 
be guided by external conditions, allowing the temperature inside to fall 
correspondingly with that outside, so that there may be no great progress 
made except on sunny days. The pipes should be warmed early in the 
day, and the walls and paths damped when there is the prospect of sun, 
so that a little air may be given to dry up or change the atmosphere. The 
day temperature should be maintained at 50° to 55°, with 10° rise from sun 
heat, losing no opportunity of admitting air, commencing ventilation at 
60°, from which the temperature may recede through the night to 40° or 
45° in the morning. With fine weather it is surprising how the plants 
progress in the new year, and it is then a good plan to start a batch of at 
least two varieties, so that one will come in after the other in succession. 
Before the plants flower examine them closely for aphides, and if any are 
pre:ent fumigate moderately on two or three consetutive evenings. L 'ok 
