MANURE.
The question of shade is, as we have seen, a highly complicated one, and
is also, as we shall see, a cause of complication in the subject we are
now about to consider; for, were no shade required, the subject of
manuring the land for coffee would, comparatively speaking, be a simple
one. And it is very important to call attention to this point, because
hitherto planters have not in any way allowed shade to disturb their
manurial practices, but have applied their manures equally to land under
the direct shade of the trees, and to the open spaces between them, which
are only under the influence of lateral shade, or, in other words, have
manured their land as if there were no shade trees on it whatever. A
little consideration, however, will show that the kinds and qualities of
the manures applied should be quite different under the shade of trees,
from what they ought to be in the open spaces between them. For, close
around the stems of the shade trees we have a large leaf deposit, which
manures the soil and maintains its physical condition, and, at the same
time, comparatively speaking, small crops of coffee, while in the open
spaces between the shade trees we have a small amount of leaf deposit, and
much heavier crops of coffee. If, then, we further take into consideration
the fact that the soil between the shade trees is liable to be
deteriorated by a greater exposure to wash and to baking from the sun
after the soil has been thoroughly soaked, it is evident that manuring
should be largely varied both in quality and quantity, if we are at once
to manure efficiently and economically. And I desire the more particularly
to call attention to this matter, because no planter, as far as I am
aware, has at all studied the subject. And it is principally of very great
importance because what we call bulk manures, i.e., farmyard manures,
pulp, composts, and top soil, are difficult to procure in large
quantities, and cost much to apply, as they have to be carried on coolies'
heads, and often for considerable distances, down the rows of coffee
trees. The more, then, we can limit our applications of bulk manure to
such lands as urgently require them, the better shall we be able to devote
a full supply to the soil which most requires such manures. Now if we
apply our bulk manures to the land directly under the shade trees, we
shall certainly be injudiciously using our mammal resources, because the
leaf deposit under the shade trees supplies exactly that kind of padding
which gives its chief value to bulk manures, and, if these opinions are
sound, it therefore follows that we should, as a rule, apply all our bulk
manures to the spaces between the shade trees, and only apply them to the
land under the shade trees, when, from the soil being of a clayey
character, an occasional application of bulk manure may be required to
improve the texture of the soil, or, in other words, make it more easily
workable. And it also follows that we should only apply bones, lime, and
ashes, fish and oil-cake to the coffee under the direct influence of the
shade trees.
But there is another question as regards manuring under the shade trees
that requires careful consideration, and that is, whether we can, by heavy
manuring, produce in such situations a larger crop than we could by a
small application of manure, and from an experiment made by the late Mr.
Pringle, formerly chemist on Messrs. Matheson and Co.'s estates in Coorg,
it would seem to be a waste of money to supply more than a very moderate
amount to the coffee directly under the shade trees, for he found that a
considerable increase in the quantity of manure gave no increase in the
crop. But I do not, of course, accept this experiment as conclusive, as it
was made with bones alone, and it is possible that a more favourable
result might have been obtained had an application of foliage stimulating
manure been used as well, for the growth of new wood under shade is
extremely slow, and it is probable that this slow growth, by giving an
insufficient supply of young wood, is really the main cause of the yield
under the shade trees being so much less than that from the coffee in the
spaces between them. But the whole of this branch of my subject requires
further careful experiment and observation before we can arrive at any
definite conclusion. In the meanwhile, and till it can be shown that, with
the aid of foliage stimulating manures, we can increase the yield under
the direct shade of the trees, it is evident that as coffee under direct
shade produces less than coffee in the spaces between the shade trees, the
coffee that produces more should have a larger supply of manure.
It is hardly necessary to add here that, in order to prevent confusion,
the whole field of coffee to be operated on should first of all be manured
evenly all over with the quantity and quality of manure which it is
advisable to use under the shade trees. After that, additional manure
should be applied to the spaces between the shade trees. It is quite clear
to me that a great economy of manure would be effected by this practice,
and that from not applying bulk manures to the coffee under the shade
trees, the physical condition of the land in the spaces between them
could be maintained in a much more satisfactory degree than it is at
present.
Then there is another question which, I believe, has hitherto escaped
notice, and that is, as to whether we should not make some alteration in
the kinds of manure so as to suit them better to the various aspects we
have to deal with, for even in land of the same quality, and treated in
precisely the same way, there is a considerable difference in the
appearance of the coffee when we pass from an eastern or southern aspect
to a western one, and a very great and marked difference is at once
perceptible when you enter the coffee on a northern aspect. In the
last-named case the coffee is nearly always green, and steadily but slowly
growing, while on the southern and eastern aspects the coffee in the hot
weather is apt to present a dried-up and sickly appearance. Then on these
two last-named aspects there is commonly an over supply of suddenly grown
wood. We should therefore, I think, increase foliage-stimulating manures
on northern aspects, and diminish them on the southern and eastern, while
we should have a medium degree of such manure in the case of western
aspects. It seems to me that the reasoning in favour of
foliage-stimulating manures on northern aspects is the same as in the case
of coffee trees under direct tree shade, which always prevents the rapid
growth of new wood. But on this point, as well as on that in the previous
section, experiments must be made before any definite conclusion can be
arrived at.
The quantity of manure that should be annually supplied is evidently a
matter of the greatest importance, and here the first thing to be borne in
mind is that of the four manures we require, namely, lime, nitrogen,
phosphoric acid, and potash, the first two are somewhat easily removed
from the soil, while the last two are firmly retained by it. It is
evident, then, that lime and nitrogen should be applied little and often,
while phosphoric acid and potash may be applied either little and often,
or in large quantities at longer intervals, whichever may be found most
convenient. But in the opinion of an eminent agricultural chemist whom I
have specially consulted on the subject, nitrogen, if applied in slowly
decomposing form, as for instance, in the shape of oil-cake, would only be
lost in an infinitesimal degree, but still he admits that there would be a
loss, and as we cannot tell what that loss may amount to under the
influence of our tropical climate and deluges of rain, it would be safe to
assume that nitrogen, as well as lime, should be put down at short
intervals and, in order to make up for the escape of these manures from
the soil, in larger proportions than either phosphoric acid or potash.
I have pointed out that phosphoric acid is retained by the soil, and it is
important to remember that it is only removed by the crops of coffee to
the extent of from one-and-a-half to two pounds per acre per annum, and
these are two facts that every planter should bear in mind when he
contemplates following the common custom of manuring with bones. For if he
remembers that about one-half of the bones consists of phosphate of lime,
and that about one-half of the latter consists of phosphoric acid, he will
at a glance see, when he estimates the amount of phosphoric acid removed
by the crops, that if he puts down even 100 lbs. of bones per acre he will
have put down enough phosphoric acid for about twelve crops of coffee. And
yet for a planter to put down 3 cwt. of bones per annum regularly is quite
a common thing, and a friend of mine, after having manured his land one
year with bones to a moderate amount, put down each year, for the two
following years, no less than three-quarters of a ton of bone-meal per
acre. So that, making a large allowance for the phosphoric acid taken up
by the shade trees, he had put down, in these last two years, enough
phosphoric acid to last for the crops of 300 years. From the application
of bones he had undoubtedly obtained a great benefit, but I feel sure that
it was from the lime and the nitrogen of the bones, for the application of
bones that preceded the two applications of three-quarters of a ton per
annum must have left the soil amply supplied with phosphoric acid. Now
assuming that the soil required lime, and a moderate degree of nitrogen,
these could have been supplied far more cheaply, and just as efficiently
had my friend applied a small dressing of ordinary lime, and some
oil-cake, and I am the more convinced of the accuracy of this view after
visiting Mr. Reilly's Hillgrove estate near Coonoor on the slopes of the
Nilgiri hills, and hearing the result of his very long experience. Bones
he had never used but once, and that on a small portion of the estate, but
he had always applied lime once every three years at the rate of about 4
or 5 cwt. per acre; the other manures he had used were cattle manure, and
town manure from Coonoor, and these added to the small quantity originally
in the soil, had supplied his coffee amply with the 2 lbs. of phosphoric
acid annually removed by the crops. After much consideration, and hearing
Mr. Reilly's views, it seems quite clear to me that as but a small
quantity of phosphoric acid is removed by the crops, and as that manure is
firmly retained by the soil, bones need only be used at long intervals
provided lime is regularly applied in small quantities.
And next, before we can approach, or attempt to determine, the quantity of
manure required, we have to take into account the loss by wash, either
from the surface or by downward percolation, and the absorption of manure
by the roots of the shade trees. We have also to take into consideration
the manure returned by the shade trees in the shape of fallen leaves, and
the ammonia derived from the rainfall, so that it is impossible to state
with any approach to accuracy the amount of manure that should be
applied. We can only say then that, whatever the required amount may be it
must be very considerable, for in addition to the above-mentioned losses
of manure, we require a considerable amount for the demands of the coffee
trees, and that, further, it must vary with the amount of the rainfall,
and the retentive or non-retentive character of the soil. The crop, it is
true, takes comparatively little from the soil, and Mr. John Hughes,
Agricultural Chemist, 79, Mark Lane,--points out in his "Reports on Ceylon
Soils and Coffee Manures," that 5 cwt. of parchment coffee an acre, which
is an average crop over a long series of years, only removes from the
soil--
lbs.
Nitrogen 8-1/4
Potash 7-1/2
Phosphoric acid 1-1/2
Lime 1
------
Total 18-1/4
Assuming then, he tells us, that the small quantity of potash required
could be supplied by the soil, and that the pulp is returned to it, the
loss by the crops could be fully supplied by 100 lbs. of castor cake and
10 lbs. of bones per acre. Then if we require much more from the plant
than the production of crop (for we expect it, in addition, to grow wood
for the succeeding crop, and during this process the plant grows much
superfluous wood, besides suckers, which have to be removed), it must be
remembered that all primings and superfluous wood are left on the land.
What there is actually carried off it is really very small in quantity.
Why, then, it will naturally be asked, is it necessary that so much manure
should be present in the soil if we wish to grow good coffee and have
continuously good crops, and why is it that if manuring is neglected you
will soon find that it is only the rich hollows that are able to maintain
the coffee in good condition and produce good crops continuously? To such
questions no distinct answer can be given, and we can only conjecture that
coffee, when it wants its food, must, for some unknown reason, have a
considerable supply at hand. There is, however, one test which, I think,
always shows conclusively whether this food is present in the quantity
required to supply the needs of the plant. Just before the hot weather the
coffee trees throw out a small flush of young wood. Now if the trees have
given a fair average crop, and at the same time have a good show of
bearing wood for the next season's crop, and are also throwing out a good
supply of vigorous young shoots, then you may be sure that your land is
well fed. But if the trees throw out no young shoots at that time, or very
few, then you will know that your land is not as well fed as it ought to
be.
It might naturally be supposed that I could furnish some guide to the
planter, from our experience in Mysore, as to the quantity of manure that
should be put down, but I regret to say that I am unable to do so, as I
know of no estate where a regular and continuous system of manuring has
been carried out. But in North Coorg, and very close to the Mysore Border,
the continuous practice on Mr. Mangles's Coovercolley Estate of 500 acres
gives a fairly approximate idea of what can keep an estate in a well-fed
condition. There the practice has been to put down every third year from 7
to 10 cwt. of bone-meal an acre, and one-third of a bushel of cattle
manure, and, besides this, composts of pulp, mixed with top soil and lime.
Now this is the finest estate I ever saw. The coffee was even and of a
beautiful colour, and when I saw it towards the end of 1891 there was a
fair crop of coffee on the trees, and an ample supply of young wood for
the following crop, and the land was so well fed with nitrogen that an
experimental application of nitrate of soda to a part of the land had
produced no perceptible effect on the trees. From what I have previously
said as to the application of bone-meal being overdone, I think it
probable that the estate would have presented as good an appearance had
the land, after once being well stored with phosphoric acid, been treated
with small applications of lime instead of bones. Then another estate I
saw in 1891 in Coorg, in the Bamboo district, furnished some guide as to
the amount of manure required where cattle manure was not available, and
on the estate in question, which had both a good crop on the trees and
ample wood for the future, I was informed that, in the year previous, 6
cwt. of castor cake and 3 cwt. of bones had been applied per acre, and
that for the four preceding years 4-1/3 cwt. of manure, containing 2 parts
of castor to I of bones, had been applied, but that the last-named amount
had been found to be too small. The reader will find in the chapter on
Coorg some further information, which has since been supplied to me by Mr.
Meynell, on this point.
The quantity of manure that should be put down at a time is evidently a
matter of great importance, as if you begin by putting down a large
application you are certain to have an over-heavy crop, followed by
exhaustion, and a very poor crop the following year, while the object of
all intelligent fruit cultivators is to work for moderate even crops. It
seems quite clear, then, that we should manure little and often, as you
thereby not only avoid the risk of over-heavy crops, but economize your
manure. For is it not obvious that if you put down at once a supply of
nitrogen and lime to last for three years, you increase the risk of loss
from wash and downward percolation? And it must also be considered that an
over-heavy crop leaves the trees in an exhausted and dried-up state to go
through the hot weather, when they will be liable to be attacked by the
Borer insect, which, as we shall afterwards more particularly see,
delights in dry wood. So that when we further take into consideration the
injury to the constitution of the trees which is caused by over-heavy
crops, we need have no doubt that there is much reason to dread them. I
would therefore strongly deprecate, for the preceding reasons, heavy
manuring (even the mind may be over-manured in the eager desire to arrive
at a cultured intellect), and would advise that a beginning be made with a
moderate application, and, if this is found to be insufficient, that the
amount be gradually increased till the trees show that they can with case
give regular average crops. If cattle manure or jungle top soil is
available, a quarter of a bushel a tree may be annually applied of either,
accompanied by 3 cwt. of bone-meal. And, if neither of the two former
sources are available, then 3 cwt. of bone-meal and 2 cwt. of white castor
cakes would be a reasonable application. After applying 3 cwt. of
bone-meal per acre for three consecutive years the land ought to be amply
stocked with phosphoric acid, and the bone-meal should be discontinued,
and its place supplied with small applications of lime, either annually or
at intervals of two or three years, should the latter course be more
convenient. And subsequently, when there is reason to suppose that the
land requires a fresh supply of phosphoric acid, an application of
bone-meal may again be used. I would particularly warn the planter against
over-manuring light dry soil, or south and south-western aspects, or the
upper and drier portions of eastern aspects, as an over-heavy crop on
these aspects is very perilous even with good shade, for we may not have a
drop of rain from November till April, and should such a drought occur,
and be preceded by a dry season (and such seasons occurred in 1865 and
1866, and caused the great attack of the Borer insect, which was so fatal
to all insufficiently-shaded coffee, and from which even well-shaded
coffee suffered to some extent), or should even a single dry, hot season
follow immediately after the crop is picked, there would be sure to be a
serious drying up of the plant, with but small chance of its bearing
anything worth having the season following, and very great risk of a
severe attack of Borer. But on northern and north-western aspects the land
is not exposed to parching east winds, and, as we have seen, has a
temperature about one-half cooler than that on a southern aspect, and the
planter may therefore on such aspects manure with greater freedom. But
even in these aspects I am sure that over-heavy manuring will lead
ultimately to injury to the trees, and, in a series of years, to the
production of a smaller amount of coffee.
I have indicated the amount of manure which in my opinion ought to be put
down when manure is applied for the first time on a plantation, and if the
plantation is of a flat character, or only on very moderate slopes, the
manure should be evenly applied all over it. But if, as often happens,
there are hollows and ridges on the land, then the ridges should be, as a
rule, much more heavily manured than the hollows, for which a very little
manure will suffice, as so much is washed into them, and they are,
besides, much richer to start with. It is very important to note at the
outset all those spots which, in the original forest, are very rich, so
that the manure may be applied accordingly, and though, as I have said,
the ridges as a rule are poor, there are many instances where the top of a
ridge, from being pretty wide, is rich, though the sides of it for a
little way down are nearly always poor. I have lately been minutely
examining old forest land, with the view of removing top soil from it, and
have been much struck with the variation in the depth of the rich surface
soil.
We have next to consider the time of year at which manure should be
applied to the land, and here we shall find that the planter, like the
farmer, often has to do things when he can, and not when he should, and
though, from the risk of loss by wash alone, there can be no doubt that
all manures should be put down after the heavy rains of the monsoon are
over, it is difficult to see how this can be carried out in the case of
bulk manures, on account of the difficulty of getting enough labour to at
once cope with the ordinary estate work, and apply a class of manure which
absorbs so much hand labour. Then there is the difficulty of carting
manure at that season when the roads, which are not macadamized, would be
cut to pieces. But this difficulty could be overcome were a sufficient
number of storage sheds provided to which the manure might be carted
during the dry season. But the sheds would cost a good deal of money, and
the cost of the manure would be increased by the cost of extra handling,
or in other words putting the manure in the sheds and taking it out again.
So that I am inclined to think that it would be better to apply, by direct
cartage from the cattle sheds, as much bulk manure as can be applied in
the month of September, and the remainder at any convenient time after
crop. Another great objection to applying manure after crop, and before
the monsoon, is, that you stimulate the growth of the weeds which spring
up with the early rains, and also much growth of suckers, and superfluous
wood in the coffee, all of which have to be handled off at considerable
expense, whereas, it is hardly necessary to say, that the weed growth is
smaller at the end of the monsoon, and the force of the plant directed
rather to the maturing of the berry than the growth of surplus wood. But
in the case of light manures such as bones and castor cake, there is no
difficulty in applying them in September, and an effort should certainly
be made to put them down then. Another advantage of manuring at the end of
the monsoon would be that the planter could then clearly perceive what
trees would be certain to give a good crop, and give them an extra
quantity of manure, and also diminish his application of manure in the
case of such parts of the plantation as might be yielding a small crop. I
may here mention that, from reliable information received from Coorg,
results there have shown that it is best to apply a portion of the manure
after crop to strengthen the blossom, and a portion after the heavy
monsoon rains are over to strengthen the trees and assist in maturing the
crop.
But the most important point, perhaps, as regards the best time for
manuring is the bearing that the time of manurial application has on leaf
disease, and Mr. Marshall Ward in his third report on leaf disease (p. 15)
has some most valuable remarks on this question. "The object of the
planter should be," he says "to produce mature leaves as soon as possible
and keep them on the branches as long as possible." Now if leaves are
produced in April and May they become attacked by the fungus while still
young, and in August and September the ripening crop is left bare on the
branches. But the leaves which were in bud in December are matured and
well hardened, and have already, by living longer, done much service to
the tree. He then points out that when certain districts in Ceylon
suffered from a bad attack of leaf disease in July, "a large surface of
young and succulent leaves were ready to receive the spores of the
Hemeleïa." The germination of the spores was rapid, and the young leaves
were soon destroyed. The planter then, he says, should manure and prune so
as to grow matured leaves during those months when the least damp and wind
may be expected. And the same remarks are evidently equally valuable as
regards rot, and show us the necessity of modifying our manurial and
pruning practices so as to enable the tree the better to contend against
it as well as leaf disease. All manuring, then, which leads to the
production of young succulent foliage just at the beginning of the rains
should be avoided, and the same remark applies equally to pruning. But I
shall again return to the subject when writing on pruning.
As to the best method of applying the manure, great differences of opinion
and practice exist. At one time in Mysore it was customary to cut a
shallow trench in the shape of a half moon around the upper sides of the
trees about two feet from the stem, and deep enough to contain the manure,
which was then covered in with the soil taken out. But this process was
found to be expensive, and of course took much labour, which is sometimes
extremely scarce, and on my property we have for some years
past--excepting in the case of manuring with fish, which is liable to be
carried off by birds, dogs, jackals, and village pigs--scattered all the
manure on the surface, and close around the stem of the tree, with the
idea that the manure would be less likely to be taken up by weeds, and by
the roots of the shade trees. But in connection with this system there is
a fact which I did not take into account, but which is well worthy of
careful consideration, and that is, that the tendency of such a system of
manuring is to keep the coffee roots close to the surface. Now it has been
suggested by the late Mr. Pringle, whose opinion on another matter I have
previously given, that this would have an unfavourable effect, if we had,
as sometimes happens, deficient blossom showers; as in that case, and with
many rootlets near the surface, a stimulus would be given to the plant
which would induce it to throw out the blossom when there was not enough
rain to bring it to perfection; whereas, if, by putting down the manure
more deeply we attracted the roots downwards, the blossom buds could only
be started after such an amount of rain as would give the soil such a
soaking that a successful blossom would be insured. There certainly seems
to me to be a great deal in this idea, but I am not aware that we have had
any experiments made side by side as regards surface manuring, and
manuring in pits, and therefore am not in a position to express a decided
opinion on the subject, but theoretically there would seem to be much in
favour of burying manure in pits, and it seems certain that the manure
would be less likely to be taken up by weeds than in the case of surface
manuring.
I need hardly add that in the case of all steep parts of a plantation all
manure should be, if not buried deeply, at least covered with soil after
the digging of a trench large enough to contain the manure. On the
plantations on the Nilgiri Hills the manure is put into pits 2-1/2 feet
long, 1 foot 6 inches wide, and 1 foot deep on the lower side of the pit,
which of course would make the side of the pit on the upper side of them
much more than one foot in depth. The trenches or pits are dug across the
slope and in front of each coffee tree, and in the line (i.e., not in the
centre of each set of four plants). These pits are not filled up to the
brim, but the manure is placed in the bottom of them, and is then covered
with soil, so that the pit is about one-half filled up. The soil taken out
is heaped in a curve above the pit so as to prevent heavy rain washing
down into the pit. When more manure is required to be added--say
bone-meal--it is scattered on the soil in the pit, or the top soil in it
is scraped off and the manure scattered and then covered up.
I now propose to consider our manurial resources in detail, and shall
begin with the first stay of all agriculture, farmyard manure, as to the
value of which for coffee I have never met with any difference of opinion.
But there are many objections to relying on farmyard manure, or, at least,
to applying it on a large scale, as, if the planter keeps many cattle of
his own, he runs great risk of his herd being invaded by disease, and the
difficulty and expense of feeding a large number of cattle is very
considerable. In some cases it is possible to hire cattle from the
natives, and this is done occasionally, and at the rate of 15 rupees a
month for 100 head, but here again risk from disease is often incurred,
and if it broke out, the natives would withdraw their cattle. The question
then naturally arises whether, considering the great cost and trouble
attendant on manufacturing cattle manure on a large scale, we cannot find
some substitute that would diminish the quantity now required. And here it
is important to ask what farmyard manure consists of. It consists, then,
of the excreta of animals, and the vegetable matter used as litter. From a
chemical point of view it mainly provides, in addition to the organic
matter, in a slowly-acting form, lime, nitrogen, potash, and phosphoric
acid, and from a physical point of view it furnishes a padding to maintain
the texture of the soil, or, in other words, to keep it in a loose and
friable condition. And with reference to this last very important point, I
may remind the reader that Sir John Lawes has well pointed out that "All
our experiments tend to show that it is the physical condition of the
soil, its capacity for absorbing and retaining moisture, its permeability
to roots, and its capacity for absorbing and radiating heat, that is of
more importance than its strictly-speaking chemical composition." Now as
regards the chemical aspect of the manurial question, if we assume, as we
have every reason to do from the small quantity of potash required, and
its supply from decomposing stones in the land, that the potash does not
require to be taken into account, we shall find that our nitrogen and
phosphoric acid can be far more cheaply supplied by fish, or by a mixture
of bone-meal and oil-cake than by farmyard manure, and should it be found
that potash does require to be added, we could obtain it more cheaply from
ashes or kainit. Then in order to provide the padding that farmyard manure
supplies, and to furnish nitrogen in a slowly-acting form, we could
collect dry leaves, twigs from jungle trees, ferns, and any other
available vegetable matter, form them into a compost with some earth, or
jungle top soil, and apply the mixture to the land. With such a compost as
I have suggested, bone-meal or fish-manure in small quantity might be
mixed, and we should then have a very good substitute for all the chemical
and physical advantages to be derived from the very best kind of farmyard
manure. But there is another way of arriving at the same end, which is
open to many planters, and that is by collecting top soil from the fringe
of jungle commonly left round the plantation, or from the uncultivated
jungle of the estate, or from adjacent pieces of jungle land. And such
pieces of land varying from ten to twenty acres can commonly be purchased,
and can be used to supply top soil. This, of course, has in it much
vegetable matter in various stages of decay, and a mixture of it with a
small quantity of bone-meal would form a manure superior, as I shall
afterwards show when I come to treat of top soil, to farmyard manure
chemically, and superior to it from a physical point of view. To such
local manurial resources I would call particular attention, as planters
have hitherto relied far too exclusively on cattle manure, and imported
manures, such as bones, fish, and oil-cake, and it is evident that we
could dispense with much of all these manures if we made a full use of the
resources I have recommended. In concluding my remarks on cattle manure I
may observe that it is both costly to supply and to apply to the land. It
is difficult, of course, to make exact calculations on the subject, as the
facilities for supplying litter vary so much, but generally speaking it
costs from 70 to 80 rupees an acre if we manure at about the rate of a
third of a bushel per tree.
I now turn to a consideration of the value of jungle top soil, a manure to
which I have only lately given particular attention, though I was, of
course, well aware of its value in a general way, and may begin by
stating that two samples of what we were using on my estates have been
analyzed by Dr. Voelcker, the object being partly to ascertain the value
of the soil and partly to compare its cost with the cost of cattle manure.
After estimating the cost of making cattle manure, and calculating as
closely as possible the cost of obtaining and applying jungle top soil
from land adjacent to the plantation, it was found that in the case of the
best sample of top soil, obtained by removing only four or five inches of
the soil, it paid nearly twice as well to use it as a manurial agent as it
would to use cattle manure, and I may add that three tons of the soil
contain the same manurial matter as two tons of ordinary well-made English
farmyard manure. In the case of the second sample analyzed, and which I
was sure from the character of the land must be of inferior quality, it
was found that 2-1/4 tons of the soil would contain as much manurial value
as one ton of farmyard manure, and that the cost of using the two
materials would be about the same.
I had also analyzed at the same time a sample of a kind of decayed
pink-coloured rock, as I had found that coffee had thriven well in the
pink soil which had evidently been formed from the rock in question, but
the manurial value was so small that Dr. Voelcker thought that it might
merely be of use in improving the physical condition of the soil. I
however applied it to some backward coffee, and also applied some of the
best top soil to a contiguous piece of backward coffee, and was much
surprised to find that the pink soil, to which little direct manurial
value was attached by Dr. Voelcker, showed results superior to the best
top soil applied alongside of it, and I am now applying it on a large
scale. This soil, I may mention, is applied by the natives to the surface
of their vegetable beds. They do not attach any manurial value to it, but
apply it to keep the vegetables cool, as the soil has quite a remarkable
effect in keeping itself cool while the adjacent soil is quite hot, and I
have now applied it to the flower beds near my house, and also to the
walks around the bungalow. This pink decayed rock is sometimes streaked
with a white decayed rock, which the natives call jadi mannu, and
sometimes the latter so much preponderates that it looks nearly white. I
am told by the natives that if you mix the red and white earth together
and apply the mixture to the surface of the land it will never get
dry.[54]
In concluding my remarks on soil applications, I may observe that if top
soil costs the same price as cattle manure, the former is to be preferred
for four reasons. It is much more easily handled and applied; it is a
better substance for mixing with other manures, such as bonedust or ashes,
for instance; it has a better physical effect on the soil; and is nearly
free from weed seeds which abound in cattle manure.
I may add that I have since made a calculation with the object of seeing
how, by the addition of manures to the kemmannu soil, I could make a
mixture which would have all the fertilizing ingredients of farmyard
manure in addition to the advantages possessed by the soil, and which I
have just enumerated. I find that if to 83 parts of the soil I added 1
part of bonedust, 12 parts of castor cake, 2 parts of potash salt, and 2
parts of lime, I should make up a compost equal to good English farmyard
manure, and at but a slightly increased cost, which would be more than
covered by the special physical and other advantages arising from the use
of kemmannu.
The pulp of the coffee is very apt to be carelessly treated, and it is
important to remember that Mr. Hughes, in his "Report on Ceylon Coffee,
Soils, and Manures," estimates that, _if properly preserved_, two tons of
pulp are equal to one ton of good farmyard manure. But it must not be
washed, as it often is by being run into a pulp pit with water, or nearly
all its valuable constituents would be lost. It should be mixed, he tells
us, with cattle dung, or, if that is not procurable, with liberal supplies
of lime, and he also suggests that it should be put under cover day by
day. We have adopted on my property a plan which I think in these climates
is the cheapest and best. A layer of top soil is placed in the road
alongside of the coffee where we desire to use the manure; then each day's
pulp is carted direct to the plantation and scattered over the top soil,
and more top soil added, till we have a layer as thick as we find
convenient, but of course not so thick as to prevent carts passing over it
to other parts of the plantation. On these layers of pulp and top soil
lime or bonedust may be sprinkled.
Dry fallen leaves is another local resource which should by no means be
neglected, and they are commonly used for littering the cattle sheds. Such
leaves are about equal to cattle dung. A sample of those we use was
analyzed by Dr. Voelcker, and the result gave 1 per cent. of phosphate of
lime, 1 per cent. of ammonia, and 3/4 per cent. of potash.
Green twigs[55] cut from jungle trees are of considerable manurial value,
and the natives seem well aware of the value of the different kinds. A
sample of the following six kinds which are most approved of by the
natives--namely, Japel, Nairal, Ubble, Gowl, Mutty and Hunchotee, was
analyzed by Dr. Voelcker, and the result gave 1/4 per cent. phosphate of
lime, 3/4 per cent. of potash, 1 per cent. of lime, and 3/4 per cent. of
nitrogen.
Ferns are of considerable manurial value, and are rich in potash, and they
should be used to litter the cattle sheds.
Burnt earth has been formerly used in Ceylon, and has been recommended by
Mr. Pringle for use in Coorg, but I have no experience of its use, but if
it pays to use it in Coorg it would pay equally well to do so in Mysore.
Wood ashes are much valued in Ceylon, where they are applied at a cost of
1s. 3-1/2d. a bushel. We buy ashes at 2 annas (less than 3d.) a bushel
delivered on the estate. Though costing as much as 1s. 3-1/2d. in Ceylon,
Mr. Hughes says they are the cheapest form in which potash can be supplied
there.
It should be remembered that the ashes of the stem wood and thick branches
are not nearly so valuable as those of young branches and twigs. A good
sample of the last-named contains 20-1/2 per cent. of potash and more than
30 per cent. of lime. In many places in the vicinity of the estates much
good manure might often be made by cutting down weeds and jungle plants of
any kind, burning them, mixed with earth, slowly, and applying the mixture
to the coffee.
I have only heard of one planter who used night soil. He had planks
pierced with the necessary apertures, underneath which buckets with some
soil in each were placed; these were removed daily and emptied into
renovation pits in the coffee. Anybody depositing elsewhere was fined, and
the fine given to the Toty, who had thus an interest in looking out for
defaulters. There can be no doubt that this is an excellent system, and
obviously advantageous from a sanitary point of view, and that it could
with, ease be carried out on an estate where all the coolies were of the
lower castes, but it could not be carried out, and it would be very unwise
to attempt it, in the case of an estate on which there are poor members of
the better castes. It is even important on such a property to see that no
pieces of ordinary paper find their way on to the farmyard manure heap,
as, when such has been detected on my property, the women of the better
castes refused to carry out the manure.
We have now examined what I may call the local manurial resources, and I
propose to consider in detail those manures which have to be imported into
the coffee districts from various quarters. Of these manures lime is one
of the most important, and as three samples of soil from my property were
all found to be very deficient in lime, it is probable that applications
of lime are as desirable in Mysore generally as they are in the case of
plantations on the Nilgiri slopes. Limestone can be procured from the
interior of Mysore, and also from the port of Mangalore. It should always
be burnt on the estate. It is a cheaper plan than having it burnt before
importing it, and we got, besides, the ashes of the wood used for burning
the lime. Lime is as valuable ground as burnt, and when it is ground is
not so liable to suffer from rain as burnt lime is. It must not be mixed
with bonedust, oil-cake, or potash salts, but should be put down some
weeks before these manures. Lime should only be used in small quantities
of half a ton or a ton an acre (it is usually used at the latter rate in
Ceylon), as a free use of it would favour the escape of ammonia from the
soil by too rapidly converting inert into active nitrogen, and, as a
neighbour of mine once found, the result would probably be a heavy crop of
coffee followed by exhaustion of the tree. Lime might be advantageously
used more often where the land is liable to be soured, or where much
vegetable matter has accumulated. It should be remembered that, as ashes
contain about 30 per cent. of lime, we should diminish the quantity of
lime when we have applied ashes. I have said that lime should be used at
the rate of half a ton to a ton an acre, but I may remind the reader that
Mr. Reilly had found that 4 or 5 cwt. regularly applied every three years
was enough, and as to the quantity that should be used, the planter must
be largely guided by the local experience. As lime is easily washed out of
the soil, it seems to me that more should be applied in the case of a
heavy, and less with a light rainfall.
Bonedust has been largely, and I think, as the reader will see from my
previous remarks, very wastefully used in manuring coffee. It varies much
in quality, and the purchaser would do well to obtain a guarantee as
regards its genuineness. Bonedust should be mixed with fine top soil, and
then applied to the land, or it may be mixed with cattle manure, or
applied as a surface dressing, but either of the two first-named methods
of application is to be preferred. In 500 lbs. of bones there are, in
round numbers, about 250 lbs. of phosphate of lime, which consists of 125
lbs. of phosphoric acid and as many of lime. I may remind the reader that
5 cwt. of parchment takes from the soil 1 lb. of lime and 1-1/2 lb. of
phosphoric acid.
Fish manure is of great value, especially in bringing rapidly on backward
or sticky coffee. A sample I have had analyzed contained 7-1/3 per cent.
of ammonia and nearly 9-1/2 per cent. of phosphate of lime. The whole fish
can be imported from the coast, and they should be broken up and mixed
with top soil. This is not only advantageous for distributing the manure
throughout the land when it is applied, but it is particularly necessary
in the case of fish, as I have found by practical experience that, if
applied whole and covered with soil, crows, kites, jackals and pigs dig
them up and carry them off.
Oil-cakes of various kinds have always been a favourite manure, and it is
a particularly desirable one, because the nitrogen in it is in a slowly
convertible form. Of all the cakes castor is said to be of the highest
manurial value (though an analysis I have had made of ground nut cakes
gives a better result in nitrogen), and besides nitrogen it contains
phosphate of lime, magnesia, and potash. In an analysis I had made of
brown castor oil-cake, i.e., cake made after crushing the entire seeds,
there was over 4 per cent. of phosphate of lime, or about equal to 5 per
cent. had the cake been white castor, which is made after the seeds have
been decorticated. But another sample of brown castor which was analyzed
for me, only gave a little more than 2-3/4 per cent. of phosphate of lime.
From this difference, and from the general consideration of the
differences of all seeds in particular seasons, and also in some degree
from various soils, it seems to me there must often be, from natural
causes, a considerable difference in the value of cakes. The attention of
purchasers should be directed to these differences; they should obtain, if
possible, a guarantee as to the composition of the cakes they buy, and
occasionally test the manure.
From what I have said as to the composition of castor cake, it is probable
that white castor contains from 4 to 5 per cent. of phosphate of lime, and
I desire to call particular attention to this, because oil-cake is usually
regarded purely as a nitrogenous source of manure, whereas one of the
oil-cakes commonly used--i.e., castor cake--contains an appreciable
quantity of that phosphate of lime of which bones are generally considered
to be the sole suppliers by the planter. But it is evident that if we
annually used 300 lbs. per acre of white castor, we should, even if it
contained only 4 per cent. of phosphate of lime, be supplying six times
the amount of lime and more than three times the amount of phosphoric acid
removed by an average crop of coffee, and though the lime is liable to
loss from waste, it must be remembered that the phosphoric acid is firmly
retained by the soil. It is important to remember that castor cake should,
like bones, be mixed with a considerable quantity of fine top soil, so
that the manure may be widely distributed through the soil.
Nitrate of potash, or saltpetre, is an extremely expensive manure, and not
a desirable one, because the nitrogen in it is in a too quickly
assimilable form, and is very liable to be lost in drainage. But it might
be used with effect, and in small quantities, for bringing forward
supplies, and I am informed that for this purpose it has been used with
advantage in Coorg. I have used the nitrate of potash on my property--an
experimental amount only--and it caused the trees to throw out strong and
numerous shoots. It should be bought in the form of pure nitre.
Nitrate of soda is also liable to the objection that the nitrogen in it is
in a too quickly available form, and liable to be lost. I have never used
it on my property, but from observing its effect on an estate in Coorg,
and the effect it had in causing the trees to throw out a fine supply of
young wood, can see that it might be used with great effect in rapidly
forcing forward worn-out coffee growing on an exhausted soil. But if used
for this purpose it should be backed up with a liberal supply of bones and
castor cake, or of bones and farmyard manure, or bones and top soil, as,
if not so backed up, the result would be unsatisfactory, if not
disastrous, seeing that the nitrate of soda, if applied alone, would cause
the plant to wring out everything that was available in the soil. The
application of nitrate of soda on the estate alluded to was at the rate of
2 cwt. an acre, and cost 21 rupees an acre, inclusive of the cost of
application. I saw the estate at the end of October, and the nitrate had
been put down in March previous. The wood it had been the means of
producing was very good and strong, dark green, and abundant, and the
effect of the nitrate was by no means confined to one season, for the
effect of the nitrate put down the year previous was still apparent. The
land here evidently was short of nitrogen, and hence the good effect of
the nitrate, but as I mentioned previously, an application of nitrate had
produced no perceptible effect on another estate belonging to the same
proprietor, which had been regularly well manured with bones and cattle
manure and composts, and because, of course, the land was so well supplied
with nitrogen that the coffee required no more. In concluding my remarks
on the effects of nitrate of soda, I may observe that by using this
manure, unremunerative coffee might be turned into a paying estate in less
than two years, while without the aid of it, from three to four years
would be required.
Potash is a manure as to which I can give no distinct information, or, at
least, only information of a negative kind. I once sent out a small
quantity of the muriate of potash, but my manager could perceive no
effects from it whatever, and I have been informed of an instance of its
having been applied to an estate in Coorg at the rate of one quarter of a
pound a tree, or at the rate of between 3 and 4 cwt. an acre, without any
perceptible effect having been produced from the application.
Then it must be remembered that the quantity of potash removed by an
average crop of coffee is only 7-1/2 lbs. an acre, that potash is firmly
held by the soil, and that it is constantly being supplied in small
quantities by the fallen leaves (these contain 3/4 per cent. of potash) of
the shade trees and the decomposition of stones in the soil, and in
applications of farmyard manure. And with reference to the demands for
potash by the tree, I may mention that I, in conjunction with a friend,
endeavoured to estimate the consumption of potash by the crop, and we sent
to Professor Anderson, of Glasgow, a carefully drawn sample of soil taken
from between four coffee trees from which twelve crops of coffee had been
removed without any manure being supplied, and also a sample of virgin
soil adjacent to the coffee (soil similar in every respect except that it
had not been cropped), and asked him to spare no expense in analysis. The
result was remarkable, for the soil from which the twelve crops had been
taken was found to be very little deteriorated in anything except the
quantity of lime it held, which was less than in the virgin soil. The
explanation evidently was that the leaves from the shade trees, and
perhaps decomposing stones, had supplied all the potash removed by the
crops. "Why, then," asked my friend, who had called on the Professor to
hear the result of the investigation, "can young coffee easily be grown on
the virgin soil, while it would come on very slowly and poorly in the soil
from which the twelve crops of coffee had been taken?" "Simply," was the
answer, "because the untouched virgin soil is in a beautiful physical
condition, while the soil in the plantation has been rained upon and
walked upon, and thus had its physical condition impaired." I need hardly
add that what I have just written is highly instructive, as it
corroborates what Sir John Lawes has said, and which I have previously
quoted, as to the physical condition of the soil being of more importance
than its, strictly speaking, chemical composition, and it shows us the
importance of maintaining a perfect physical condition of the soil, partly
by cultivation and partly by additions of bulk manure--farmyard
manure--top soil, and composts.
To grow young plants in old soil requires great attention to manuring and
preparing the soil, so as to supply the physical and chemical requirements
necessary for the vigorous growth of the young plants. Now we know that
the plants thrive well in virgin soil, and we cannot do better than fill
the holes with it, if it can possibly be procured within any reasonable
distance. If it cannot, then the soil should be mixed with some thoroughly
decayed and dried cattle manure, mixed with bonedust, and if it is desired
to rush the plant forward, a slight dressing of nitrate of potash might
subsequently be applied.
Coprolites, the supposed fossilized remains of animals, which would
probably contain about 40 to 50 per cent. of phosphate of lime, have been
discovered in Mysore, and I am informed by an executive Engineer officer
in the Mysore offices that they are to be found over an area of about two
square miles, and at about a distance of seven miles from the Maddur
Railway Station on the Bangalore Mysore line. This is a highly important
discovery, and, when developed, ought to be the means of furnishing the
planter with cheap supplies of the mineral phosphate of lime. I may
mention that as one find of coprolites has been made in the province, it
is highly probable that further discoveries of this valuable manure may be
made. A discovery of phosphatic nodules has also been made near
Trichinopoly, in the Madras Presidency, and though not of quality
sufficiently good for export to England, has been reported on by Dr.
Voelcker as being good enough for use amongst the plantations of Southern
India. A deposit has also been discovered in the Cuddapah district.
We have now glanced at all the local manurial resources at the command of
the planters, and also the manures which may be purchased at a distance
from the plantations, and as to the latter the question now naturally
arises as to how the planter can best lay out his money when manuring his
coffee. Now I know of no planter in India who has knowledge enough to
decide as to how he should lay out his money. The planter knows in a
general way that he wants nitrogen, phosphoric acid, lime, and perhaps
some potash, but as to the most desirable and economical sources from
which to obtain them he is unable to decide, and it is not a question,
even if he called in an agricultural chemist, to be decided once for all,
for the prices of the various manures are constantly liable to change.
Here, then, is a matter that should be taken up by the Government, which
in this respect should follow the example of the Sussex Agricultural
Association, the chemist of which publishes every spring the most
economical manurial mixture which the farmer can use for his various
purposes. In this thinly populated country the well-to-do planters are too
few, and the humble native planters too poor, to do what is done by the
rich agricultural societies of Great Britain in the way of aiding the
farmer. The societies at home are mainly composed of landlords and the
richer tenants. The Government in India is the one great landlord over
two-thirds of British India, and should perform the duties of one.
In concluding my remarks on manures, I need hardly say that it is of the
greatest importance to keep a careful record of all the manures put down,
and a special manure book should be kept for this purpose, in which notes
should be kept of the effects observed. But for ready reference I have
found it most convenient to have a plan made of each field on the estate,
and on one side of it a space should be left in order to enter the manures
applied. The date on which the field was planted might also be entered on
the plan.
Finally, I may remind the reader of the Tamul proverb which declares that
"With plenty of manure even an idiot may be a successful agriculturist,"
and may add to it the English adage, which says to the farmer, "Never get
into debt, but if you do, let it be for manure."
The work of bringing round an old and neglected plantation is by no means
an easy one. The first thing to be done is to see to the physical
condition of the land. This is sure to be hardened and deficient in
vegetable matter, and this condition of things can only be remedied by
applying large quantities of cattle manure or jungle top soil, or both.
Now it will generally be found impossible to obtain enough cattle manure
to fully manure even fifty acres in the year, nor, if it could be obtained
in large quantities, would cattle manure have nearly such lasting effects
in ameliorating the condition of the land as would applications of jungle
top soil, and besides, the latter, if procurable (which it often is), can
at once be applied in large quantities, and at about one-half the cost of
cattle manure, in the case, as has been previously shown, of the best top
soil, and at about the same cost in the case of the most inferior quality
of top soil. It is evident, then, that great efforts should be made to
procure a supply of jungle top soil, and the best top soil could of course
be carried from a considerable distance without exceeding the cost of
cattle manure. With the cattle manure or top soil, bonedust and white
castor cake should be applied at the rate of 8 cwt. an acre, and 5 cwt. of
the former to 3 cwt. of the latter; and, if the planter is in a hurry for
immediate results, he might put down a small dressing of nitrate of
soda--say 112 lbs. an acre. With the addition of the nitrate I feel
confident, after observing the results of it on one of Mr. Mangles'
estates in Coorg, that a remunerative crop would be picked in about two
years after the application of the above suggested manures. I would
particularly point out that, though the land, of course, must be well dug,
the planter must not look to that alone for ameliorating the hardened
condition of the soil, for however well dug, it will, unless cattle manure
or jungle top soil should be applied, speedily run together again into as
hardened a condition as ever. After the soil has been thoroughly manured
and ameliorated in the manner suggested, moderate annual manuring will be
quite sufficient for the future, for, as I have pointed out, coffee is not
an exhaustive crop, though it is essential that a considerable supply of
fertilizing matter should always be present in the soil. Where top soil is
not available, red soil (kemmannu), if procurable, might be used with
advantage, and the results of the experiments previously given seem to
show that it might be even preferable to top soil.
After such an application of manure as I have above advised, the planter
must be on his guard against producing such a heavy crop as will lead to
an exhaustion of the tree, and a failure of the following crop. And should
there be reason to apprehend an over heavy crop, it must be reduced by
free handling and pruning.
In the case of a neglected plantation the trees are sure to be covered
with moss and rough dead bark, and it is of great importance to remove
this at once, and rub the trees down thoroughly.
When manuring, always leave here and there, and at some convenient point
or edge of a road, a short block of coffee un-manured, perhaps about
twelve trees, and next to that a similar block with double the dose of
manure applied to the field, and note the results. In order to have the
effects of the different systems of manuring under constant observation
experiments with different manurial mixtures can be best conducted at
places where four roads meet. I need hardly say that in the observation of
results, nothing should be left to memory, but the planter, the moment he
has observed any result, should on the spot write it in his note book. The
experiments of most importance are the following:--(1) As to the manure
best calculated to bring on vacancy plants rapidly in old and worn soil.
(2) To determine the value of potash as manure. (3) To determine the best
time of year for manuring. (4) To determine how far it pays to manure
little and often, as compared with manuring seldom but in large
quantities. (5) How far the value of bones is due to their lime, and how
far to the phosphoric acid they contain; and (6) how far it would pay to
top dress old soil with earth taken from the adjacent, grass lands. Such
are some of the many experiments that might usefully be tried. It would
also be useful to experiment as regards native manurial practices. For
instance, the growers of Areca nut palms, and pepper vines, make a mixture
of Kemmannu, or red, or rather pink hued soil, which looks like
recently-decomposed rock, black earth, and sheep dung, and apply the
compost to their palms and pepper-vines, and it would be interesting to
try such composts in the case of coffee. It would also be interesting to
experiment with ordinary good soil taken from the grass lands. I am
informed by a native farmer that the terraces on which ragi is grown, are
occasionally dressed with such soil, and that the manurial effect of it
lasts for two years, but no doubt the effect is much increased by the
physical effect caused by the addition of the soil. The more I have
studied these subjects the more am I convinced that the most, economical
way of keeping up coffee land from a physical and chemical point of view
is one of the many secrets yet to be discovered, and I would strongly urge
planters to experiment. There is a common saying amongst farmers and
planters that they cannot afford to make experiments. This is merely the
refuge of the indolent and the ignorant. Experiments may, of course, be
made on such a scale as to be hazardous or even ruinous, but they can be
made in such a way as to be neither the one nor the other.
FOOTNOTES:
[54] I am now so satisfied with the capacity of these soils to keep
themselves cool, that I am applying them as a top dressing to land
deficient in shade and dry ridges. Since writing the above, I have
ascertained from my manager the interesting fact that about seven weeks
after putting down the red earth, newly grown white roots were found to be
running all through this earth, though no rain had fallen from the time of
the application of the soil up to the time the growth of the rootlets was
observed. The adjacent land, to which virgin forest top soil had been
applied, had no such growth of new rootlets, nor had any of the adjacent
land, to which no top dressings had been applied. The red earth had
evidently the power of taking in sufficient moisture from the atmosphere
to stimulate a growth of young roots. The red earth was applied on
February 20th, and no rain fell till April 7th. This growth of new
rootlets, I may add, was also observed in another part of the plantation
to which, a top dressing of the red earth had been applied.
[55] The full analyses of these leaves and twigs are given in the Appendix
to Dr. Voelcker's work, "The Improvement of Indian Agriculture," which
contains other analyses of interest to the planter. This important work
should, I may repeat, be in the hands of all those interested in tropical
cultivations.