374 
JOURNAL OF HORTICULTURE AND G011AGE GARDENER. 
[ May 7,1885. 
more important phosphorus is than nitrogen, because while phosphorus 
must be in the soil for vegetation to be healthy, nitrogen is furnished 
by the air as well as the soil, and plants are not absolutely dependent 
upon it being in the soil. Are we then to conclude that nitrogen is 
not needed because it is furnished by the air? No. IVe must not 
allow ourselves to swing to and fro like the pendulum of a clock. If we 
want to raise heavy crops, and plenty of mineral food is supplied, the 
nitrogen obtained from the air will not be sufficient, so more must be fur¬ 
nished or the plaats will not be able to avail themselves of the abundance 
of phosphorus and other minerals. Now while rain is a source of nitrogen, 
yet on the other hand it is a cause of loss of it, especially when the ground 
is bare. Now, nitrogen is easily washed from the soil too deep for roots to 
reach it, but phosphorus and other minerals stay better in the soil, so that if 
we give more of them than is required, they are still there, and can be used 
by other crops. Our soil here on the ragstone formation naturally contains 
a good supply of phosphates, and that is why it is so suitable for Hops and 
fruit, and is so fertile ; and my own belief is that where finer Hops are pro¬ 
duced than here, it is because there are more phosphates in the soil, and 
where poorer Hops, such as in the Weald of Kent, it is because the soil is 
not so rich in phosphates. The same applies to fruit. It is obvious that it 
is only the soil which makes the difference, for the air and climate are the 
same. Therefore to make our produce of equal quality, we must make our 
soil as good. 
To come from theory to practice. A firm in Maidstone from whom I 
bought some crushed bones, informed me that a Hop grower had applied 
bones (which contain a very large amount of phosphorus) to his poorest 
piece of Hop garden, with the result of getting the best Hops from it, and 
they were of such fine quality that they were eagerly bought up by the 
brewers at Burton. He has since then increased the quantity of bones he 
buys each year, and this winter has purchased of them 40 tons of crushed j 
bones, amounting to over H300. Fruit also benefits largely by phosphates 
where used, the produce being both greater and of finer quality. The wood 
of the trees is firm and full of blossom buds, and gets well ripened, in 
contrast to the large coarse growth producing nothing but leaves, caused by 
excessive supplies of nitrogen alone. When phosphates are supplied as 
well as nitrogen, I have found there has been an abundant growth of wood, 
yet of good quality and of fruitful habit of growth. I attribute this result 
as well, partly, to not disturbing and breaking the roots. I believe much 
blossom never sets, or the fruit drops off prematurely, because of lack of 
phosphates in the soil. The reason is the trees find they cannot sustain the 
fruit, for they have not got sufficient food for it to grow to perfection. To 
leave fruit and Hops (in which, no doubt, you are interested, as your work 
lies so much among them) for garden crops, we find that phosphates are 
very beneficial to Turnips, Cauliflowers, Cabbages, and, in short, all garden 
crops, for this reason, that they all contain a very large amount of phosphorus, 
and that unless it is in the soil they cannot come to perfection. Turnips 
will not grow well without a good supply of phosphates, and this is the 
reason superphosphate is so much used for them in farm cultivation. 
These things being so, it remains to be considered how the phosphates 
are to be supplied to our various crops. They may be given by means of 
dung, as mentioned under nitrogen, but not in sufficient quantity in an 
ordinary dressing; therefore should be given separately in addition. Of 
course, if we were to use sufficient dung we could give enough phosphorus 
even to those crops which require most, but this would be a very wasteful 
proceeding, for to give enough phosphorus we should have to give too much 
nitrogen, which would be wasted, and to some crops would be very injurious. 
Fifty, seventy, and eighty tons of dung per acre are sometimes employed 
by market gardeners near London, and also in America, and I have read of 
100 tons an acre being sometimes employed in a garden near Bermondsey. 
In my humble opinion, very heavy dressings of dung are a mistake, and 
the same result would be achieved much cheaper by a moderate quantity of 
dung, and by adding in other ways more phosphorus and also other minerals if 
required. As you will have seen from what I have said before, bones are very 
rich in phosphates, more than half of their weight being tri-calcic phosphate. 
The smaller they are broken the quicker will be their action, as there is 
more surface for roots to attack. If a good dressing, say at the rate of a ton 
an acre, of half-inch or quarter-inch bones were given, it need not be 
repeated under seven years ; but if the bones were crushed to dust, a smaller 
quantity, say a quarter of a ton per acre, would be sufficient, but would have 
to be repeated oftener. Bones also contain some nitrogen. If we had to 
depend on bones alone for our additional phosphates, there would not be 
sufficient, or the price would rise so as to be prohibitive, but happily phos¬ 
phates are dug out of the earth in England in the form of coprolites, and 
in the mineral form in various other places. 
The mineral phosphates may be bought ground up finely, ready for use, 
and are cheaper than bones. Superphosphate is mostly made of minerals, 
but may be had made from bones. The bones or minerals are dissolved by 
having sulphuric acid or vitriol poured over them, and some suppose that by 
being dissolved in this way they act much quicker ; but in practice it is found 
that if the bones or coprolites be finely ground they act almost as quickly, 
and are much cheaper, besides which the sulphuric acid is apt to do the 
ground harm by making it too acid, and make Turnips, &c., more liable to 
disease. Night soil is rich in phosphates, as also are fowl dung and guano, 
as I mentioned before. G-uano at the present time mostly contains more 
phosphates in proportion to its ammonia than it used to, for the highly 
ammoniacal is getting used up. There is also a fish guano, called Jensen’s 
Cod G-uano, manufactured from the heads and backbones of codfish, which 
contains a high per-centage of phosphates. They also make another from 
herrings, which, however, is not so rich in phosphates. I think we have said 
enough about phosphates, and we will now pass on to potash. 
All plants take large quantities of potash from the soil, and it is there¬ 
fore quite as important in that respect as phosphorus ; but there is this 
difference, that while nearly all soils require phosphates to be supplied, a 
great many soils have such an abundance of potash in them that they never 
require it to be supplied as manure. Other soils have scarcely any, so that 
you see, before giving it, it is necessary to see if it is wanted. Most clay 
soils never need it to be supplied, and I do not think our soil does. Last 
season I experimented with a small quantity of different trees and vegetables, 
but could not see any benefit where it was put on; even Potatoes, which 
require a very large quantity of potash, were no better in crop where it was 
used, than where it was not. Last summer was very dry, which might have 
prevented the crops having the full benefit of it, and therefore I cannot 
fully judge until after this summer. Also where Potatoes have been grown 
continuously on the same ground for a number of years, on this soil they 
may need potash. Light soils mostly require potash. Apples, Plums, Pears, 
Grapes, Cherries, and indeed all fruits take large quantities of potash from 
the soil, the ashes of those mentioned consisting of half their weight of 
potash. Potatoes, Rhubarb, Beans, and French Beans the same; while 
Peas, Celery, Onions, Cabbages, and other crops also consume a large 
amount. Potash can be supplied by dung and decayed weeds, or any vegetable 
refuse. Wood ashes are very rich in potash, as also is the animal fluid. 
Potash can be added to the soil as kainit and nitrate of potash. On those 
soils where it is deficient it must be added, because then it is as necessary as 
nitrogen and phosphorus, and if added will greatly increase the crop. 
Lime is the next element on my list. All plants are composed partly of 
lime, and therefore need it in the soil, but whether it is necessary to add it 
to the soil is a debated point. Professor Jamieson and others are not in 
favour of it, but many say that it is necessary. Probably both are right, and 
that, like potash, it depends whether it is naturally present in the soil. 
Heavy soils are considered to be improved by a good dressing of lime or 
chalk, not only by the lime being added as food for the crops, but also 
because it makes the soil easier to work, and drier, and therefore warmer. 
It is generally supplied either as lime or chalk. If I were near the pit, I 
should put on chalk, but if at a distance I should use lime, because otherwise 
the carriage would come to so much, for tons of lime are equal to 10 tons 
of chalk. Lime may also be added to the soil as marl. Bones and gypsum 
are partly composed of lime, so that when they are used a certain amount of 
lime is given by them. Lime should not be used when the soil does not 
contain much humus or vegetable mould, as it dissipates this which is 
necessary for plant life. Chalk is better to use in this case if calcareous 
matter is required. But where the soil is black with humus, as in old 
gardens that have had heavy coatings of dung and are full of decayed 
vegetation, lime is very often highly beneficial, sweetening the soil and 
rendering this black mould fit for the use of plants, other manure then not 
being required for a time. As our own soil is composed of the debris of 
Kentish ragstone, which is a limestone, it is an open question whether lime is 
needed. When roots are “ clubbed,” or as some say have “ finger and toe,” 
it is considered a sign that chalk or lime is required, as the absence of it 
will cause this disease, and it has also been found a cure for clubroot in 
Cabbages. It has been said that when water and couchgrass prevail, it 
shows that calcareous matter is required. Were I living on the Weald clay, 
or “ below the hill,” as it is called here, I should certainly use lime, and 
should not expect to grow good crops of fruit without its use. 
So much for lime, let us now consider sulphur. This is absolutely neces¬ 
sary for plants, but whether it is required to be specially applied as a manure 
is a different thing. Some hold that it may be ignored, I suppose because 
sufficient is present in the soils where they have made their experiments. 
Nevertheless it has been used as a manure, with the result of a considerable 
increase of crop in the case of Cabbages, Turnips, Clover, Peas, Beans, and 
Grass. Cabbage contains a very large amount of sulphur. The best way to 
apply it, specially as a manure, is by means of gypsum, which also consists 
largely of lime, so that is given at the same time. Benjamin Franklin 
sprinkled letters of his name with gypsum on a piece of Clover, the result 
being that his name could be afterwards read, on account of the increased 
growth of the Clover. It is considered to have the best effect if used when 
the leaves are wet, so that it sticks to them. It is said by some that using 
gypsum on Hop gardens checks the mould, and I should think it would 
perhaps prevent mildew in other plants, such as Peas. I am trying the 
effects of it this year on various garden crops, and on fruit trees, to see if 
they derive any benefit from it. If used, it is better not to give too heavy a 
dressing at one time, as it is washed out of the soil by rain. Of the other 
substances which are present in plants, such as magnesia, soda, iron, &c., and 
which agricultural chemists say may generally be ignored, I will say nothing 
except to remark that to some crops soda has been found very beneficial. It 
may be given cheaply by means of common salt, which is largely composed 
of it. Last year my Strawberries derived considerable benefit from an 
application of nitrate of soda and phosphates, and I believe it was owing 
partly to the soda, which enters very largely into the composition of this 
fruit. Cabbages, Turnips, and Mangold Wurtzel also contain a large amount 
of soda in their composition. Salt is much used for Asparagus. It has 
been found that when Turnips and Mangold Wurtzel have been manured 
with salt, in addition to other manure, that good crops have resulted in very 
bad years, when insects have carried off half tho produce on adjoining 
farms. One farmer states “he has never known the Turnip crop to fail 
where he has used it.” Salt has been found remarkably useful for getting 
rid of couch and water grass. It should be applied in autumn to land 
intended for fallow at the rate of 12 cwt. per acre. 
There is one more substance which I should like to speak of, and that is 
humus, which I have incidentally mentioned before. It is the black mould 
of soils, and is the remains of vegetable and animal matter. Gardens which 
have been well manured usually have plenty of it; but farm soil, which has 
had vegetation taken off it for a number of years, and not much dung or 
green stuff ploughed in, will be sure to be deficient in it. There is another 
benefit of dung and waste product manures over chemical manures such as 
nitrate of soda, &c., and that is, that while both supply nitrogen, the former 
supply humus as well. Green crops dug in also furnish a supply, and on 
soils deficient in humus all vegetable matter should be saved and put on the 
ground. Mr. Dean says, if a crop of Clover be grown and ploughed in 
when it begins to flower, it will give to the soil four times as much humus 
as it took out, and any vegetation grown and dug in will act in the same 
manner. You will see the difference humus makes to the soil if you compare 
the soil of an old fruit plantation with that of an arable field adjoining, 
and which it was once part of. You will find the soil of the plantation much 
darker and more friable through the leaves which have fallen from year to 
year. Humus attracts moisture to the soil and retains it well. It also helps 
to dissolve the phosphates and other minerals in the soil, and render them 
fit for use by plants, and is beneficial in other ways. On the other hand, 
there is no benefit in having too much of it, and there may be more than 
is required in old garden soils. Such are benefited by a dressing of lime, 
which will render it fit for use by plants, as I said before. I should think 
