Speculating on the probability of a dry summer, I gave it an extra
quantity of manure, and I think where guano is used afterwards, as
it is by me, the nitrate of soda might be dispensed with, which
would bring the cost to L1 2s. 6d. per acre. I should prefer guano
to nitrate of soda, because of the phosphates contained in the
former. At the distance we are from the sea (about thirty miles)
it would seldom be necessary to apply common salt, as the gales of
winter generally bring as much as is needed; but last winter we
had no high winds, and I thought that where salt was applied with
other chemical manures, the wheat was more luxuriant than where
there was none; but owing to a misunderstanding of the instructions
to that effect, the produce was not kept separate. When the chemical
manure was applied, one land was left without, for the purpose of
comparison. Guano was sowed on the land on the 29th March, at the
rate of something less than 2 cwt. to the statute acre, one side of
the field being covered with Peruvian, the other with African, and
the land on which no chemical manure had been sowed was half of it
covered with guano, and the other half left without anything except
lime; but as it was thought desirable to ascertain the value of the
chemical manure without guano, half of this patch was sowed with the
chemical manure in April, after the long drought of the last spring
had set in. A small patch was left without manure, to show the
natural condition of the field, and to serve as a comparison with
the manured part alongside it, and also with the condition of the
field when the experiment commenced, 1841-2, when the unmanured
portion yielded only 19 2/3 bushels to the acre. This part of the
experiment, however, was frustrated by the carelessness of the men
who thrashed out the wheat. The crop was a very good one throughout
the field, but was evidently shorter and thinner where there was
no lime, and also where guano was applied alone. It was best on
the headlands where more lime had been applied. The weather was
extremely favourable until the wheat was going out of bloom, but
it then changed, and the crop was beaten down by the rain, in some
places so thoroughly that it never rose again; and from that time
to the day it was reaped (21st August), there were not more than
six fine warm days. This cold and ungenial weather would, no
doubt, materially affect both the quantity and quality of the
crop,--the sample only being just fair. On thrashing out the crop,
I find the result to be as follows:--Where the guano and chemical
manure were applied, but no lime, the yield was 49 1/5 bushels of
60 lbs. per statute acre; where the land was left unsubsoiled, it
was 52 1/2 bushels; when guano alone was applied, it was 42 1/3
bushels; where the chemical manure alone was applied, it was 43
1/2 bushels; where the African guano was applied, it was 45
bushels; where the Peruvian was applied, it was 52 2/3 bushels; on
the headlands, where three times the quantity of lime (or 3 1/2
tons per acre) was applied, it was nearly 62 bushels; and where
six times the quantity of lime (or 7 tons to the acre), it was 49
2/3 bushels. I give this last result as it was ascertained, but do
not consider it conclusive, for the wheat plant on this headland
looked quite as well as the other, until it went out of bloom,
when from some unknown cause it was partially blighted; an
irregular patch from a foot to a yard in width and extending
almost from end to end of the headland becoming brown and parched,
as if affected by lightning or some atmospheric visitation. With
the view of making these results a little clearer to the eye, I
subjoin the following tabular statement of the produce per acre in
the different parts of the field:--
Bushels of 60 lbs. per statute acre.
Guano alone 42 1/3
Chemical manure alone 43 1/2
Guano and chemical manure, with 24 cwt.
lime to the acre, but land unsubsoiled 52 2/3
Guano and chemical manure, but no lime 49 1/5
African guano and lime 45
Peruvian " " 52 2/3
" " and 3 times as much lime 62
" " and 6 " " 49 2/3
Average crop throughout the field 50
It may be as well to observe, that the total expense of manure,
and of its application to that portion of the field which produced
sixty-two bushels per acre (including the guano and the additional
quantity of lime used), was at the rate of 81s. per statute acre.
Deducting the cost of the nitrate of soda, the utility of which,
under the circumstances, I am inclined to doubt, it would have
been 63s. 6d. I consider these to be very favourable results, and
as offering strong inducements to continue the experiment. I have
accordingly had the land ploughed up and cleaned; and it was again
sowed with wheat on the 9th inst. Having detailed the general
results of the experiment, I beg to offer the following remarks
upon some points in it, which seem to me to require a little
elucidation. I consider the success of this experiment to be in a
great measure owing to the use of soluble silica and magnesia;
because, although there is an abundance of silica in the soil, my
first crop showed very miserable results, the grain being ill-fed
and poor, and the straw soft and discoloured, although the year
1842 was, in this district, very favourable for wheat, the month
of August being singularly fine and warm; but when I combined the
nitrate of soda with sulphate of magnesia, as in experiment No. 1
in 1843, but still more so when I combined it with the silicate of
soda, as in No. 3 of that year, the straw became as strong, firm,
and bright as need be desired; and this year when both these salts
are combined with nitrate of soda, common salt, and gypsum, I have
not only good and bright straw, but also an abundant crop of wheat.
With respect to the lime used, it may be as well to state that the
field had not been limed for many years, and although in a
limestone district, showed a deficiency of lime on analysis. The
soil is a strong loam, on a brick clay subsoil, in which there is
little or no lime, although the stony clays, which form the
subsoil in a great part of the district, abound in it, containing
from twenty to thirty per cent. of carbonate of lime. I had always
believed that lime was used in great excess in this neighbourhood,
and had, in fact, an idea that its good qualities were overrated,
inasmuch as it does not enter into the composition of the plant,
except in very minute proportion; but last winter I saw a paper
(by Mr. Briggs of Overton) on the possibility of growing wheat on
the same land year after year, in which the utility of lime in
preventing rust was incidentally touched upon. I also saw Liebig's
letters explaining the action of quicklime in liberating potash
from the clay; and then I considered it very important to
ascertain the proper quantity to be applied. The quantity required
to decompose the phosphate of iron was not great, and assuming
Liebig's theory of its action in liberating the potash to be true,
it seemed to me that an excess of lime would permanently
impoverish the land; for, supposing that the crop required 100
lbs. of potash, and as much lime was applied as liberated 500
lbs., what became of the 400 lbs. which did not enter into the
composition of the plant? was not a large portion of this 400 lbs.
washed down the drains by the rain, and so lost for ever? Perhaps
the absence of lime in this field accounts for its beneficial
action in the experiment just detailed; but if my supposition is
correct, that any excess of potash which may be liberated from the
clay by the use of quicklime (that is, any more than may be
required to perfect the crop), is washed down the drains, and thus
the land is permanently impoverished by the excessive use of lime,
it behoves landed proprietors to ascertain what is required, and
they should take care to apply no more than is necessary. This
caution is most particularly needed in this neighbourhood, where
lime is cheap, and where the opinion is prevalent that the more
there is applied the better it is for the land, and where it is
common to apply ten or twelve tons to the acre. I have stated
above that chemical manure was applied to a small portion of the
field after the setting-in of the drought in April. The action of
this manure showed that a good thing may be very injurious if
applied at an improper time; for, although it produced a
stimulating effect on the plant immediately after its application,
there was too little moisture in the land to dissolve it
thoroughly, and thus enable the plants to appropriate it, until
the rain came, about the end of June, when the wheat had been in
flower some time; but the stimulus was then so great that all the
plants threw up fresh stalks (from the roots), which were in
flower when the wheat was cut, and it was then found that they had
not only impoverished the plants, but had prevented the grain from
ripening. This was the case not only in the experimental field,
but in several others also, where the chemical manure was sowed
after the setting-in of the drought. When the field was sowed with
guano, it was thought desirable to cover one part of it with the
African, and the other with Peruvian, for the sake of comparison;
but as the African did not appear to produce the same stimulating
effect as the other, fifty per cent. more was applied, that the
cost might be equal (the Peruvian cost 10s., the African 7s. per
cwt.); but as the latter application of the African was made when
the wheat was just shooting into ear, the same objection applies
to the experiment which does to the chemical manure applied after
the drought had set in--viz., that there was not sufficient
moisture in the soil to dissolve it thoroughly until the plant was
too far advanced to benefit by it; and therefore its failure would
be no proof of the value of the African as compared with the
Peruvian, which was the object of the experiment. It is true, no
bad effects followed the application similar to those produced by
the misapplication of the chemical manure in dry weather, yet if
soluble salts like the latter did not find sufficient moisture in
the ground when applied in April, there is reason to suppose that
the former would not do so when applied in May. I regret the
failure of the experiment without any manure, as I think the
result would have shown satisfactorily that the land is so far
from being impoverished by this system of cropping, that it is
improving every year. I think, however, that this is shown by the
produce of the land manured with guano alone. In the first year's
experiment the produce from guano alone was 27 bushels per acre,
and both straw and wheat were very indifferent in quality. This
year the produce from guano alone is 42 1/3 bushels; and although
neither straw nor wheat are so good as upon the adjoining lands,
they are both very much better than they were in 1842. It will be
observed that the result from the unsubsoiled portion is very
good, and if nothing more were said about it, people would be led
to conclude that there was no advantage in subsoiling. But this,
in my opinion, would be a great mistake; for to say nothing of the
advantage which the unsubsoiled portion would derive from the
drainage which it received from the subsoiling on each side of it,
I found, when the field was ploughed up this autumn, that whilst
the unsubsoiled portion was stiff and heavy, the subsoiled part
was comparatively friable and loose, like a garden, and will, I
expect, show its superiority in the succeeding crops. It must be
borne in mind, in reading these experiments, that we have here one
of the most unfavourable climates in the kingdom for growing
wheat, from the excessive quantity of rain that falls, three times
more rain falling annually in the north of Lancashire than at
York, and this, no doubt, is very prejudicial to the success of
such a series of experiments as I have been detailing. It has been
objected to these experiments, that allowing all to have been done
which is here detailed, it leads to no important conclusion; for
although it may be practicable to grow wheat every year, in a
small field like the one experimented on, it is not so on a large
scale. But the objectors should remember that there is not the
seed of a single weed sowed with the manure; and therefore if the
land is thoroughly cleaned, and kept so, by hoeing the crop in the
spring, it will require very little labour to fit it for another.
But I shall be better able to speak on this head next harvest,
having sowed wheat on an oat stubble with once ploughing. It is
said there are no weeds in Chinese husbandry, and if they can
eradicate them completely, so may we, if we adopt the same methods
and follow them up as perseveringly. Again, admitting that it is
not practicable to grow wheat on the same land year after year on
a large scale, yet if we can double the crop in those years in
which we do grow it, by the application of chemical manures (and
the same manures are applicable to all cereal crops), will not
that be a conclusion worth arriving at? That it is possible to do
so, is, I think, sufficiently shown by the results I have
obtained. What, then, may we expect when these experiments are
infinitely multiplied and varied, under the superintendence of
skilful and experienced men, who will devote their whole time and
attention to the subject? Will raising the average produce from
twenty-five to fifty bushels per acre be the utmost limit to which
improvement can be carried? I believe not. In conclusion, I would
urge on all owners and occupiers of land, the importance of
devoting at least a small field to agricultural experiments, as I
think there can be no doubt that, if these are carefully and
systematically made and followed up by agriculturists generally,
we shall be so far from needing an importation of corn in average
years that we shall have a large surplus to spare for our
neighbours.
NOTE.--In the use of silicates of soda and potash one precaution
is very necessary--viz., that you really have a soluble silicate,
and not a mere mechanical mixture of ground flint and soda: this
is a very different thing, and one, if it be not carefully guarded
against, which will lead to nothing but disappointment. Again, the
silicate may be properly made in the first place, but in a long
exposure to the atmosphere the soda attracts carbonic acid, and
the soda is liberated, and this has defeated my expectations more
than once. Again, though I consider it desirable to defer the
application of it until vegetation has fairly started in the
spring, yet, in one instance, I delayed the application of it so
long, that there was not moisture to dissolve it until the end of
June, and then the wheat began to shoot afresh from the roots and
the crop was seriously injured by it: but this was in an
exceedingly dry spring, and might not happen again for many years.
* * * * *
_To the same._
LOW MOOR, _18th December_, 1845.
SIR,--I promised to communicate to you the results of my attempt
to grow wheat on the same land year after year, this being the
fourth crop of wheat (the fifth white crop) grown in successive
years on the same soil, and though I consider the crop an
indifferent one, I don't think the failure ought in any degree to
be attributed to the over-cropping, but to the wetness and
coldness of the season, as well as other untoward circumstances
hereafter to be mentioned.
In a former letter of mine of the 12th October, 1844--which was
published in the "Guardian" a few days after--I gave an account of
the crop of 1844, which was a very good one, being fifty bushels
to the acre throughout the field, and as much as fifty-two bushels
in the best part of it. This I considered so satisfactory that I
had the field again ploughed up and sowed with wheat on the 9th
October, 1844, and it is to the results of this crop that I wish
to call your attention. As remarked in my former letter, the field
was subsoil ploughed in the autumn of 1843, and this subsoiling
was carried to such a depth that most of the drains in the field
were more or less injured by it; and although this did no injury
to the crop of 1844, owing to the very dry season, yet when the
rain came in the winter of 1844, the want of drainage was found to
be very prejudicial, and in the wet places large patches of the
young wheat went off altogether, and there was a great deficiency
of roots in many parts of the field; the long continuance of frost
and after that the ungenial weather which continued so long in the
spring (of 1845) were also unfavourable, yet with all these
drawbacks the appearance of the plant after the growing weather
_did_ come, was very promising, and many of my friends predicted
that I should have as good a crop as in 1844. On the 24th March I
applied chemical manure of the same kind as I had done in 1844, at
the rate of about 3 1/4 cwt. to the acre (costing 23s. 6d.), and a
fortnight after I had it sowed with 2 cwt. of guano to the acre.
When the warm weather came, these manurings seemed to help it
wonderfully, and it was, as I have before stated, a very promising
crop; but the cold, ungenial weather we had through a great part
of the summer, and the continued rain we had whilst the wheat was
in flower, destroyed all the former promise: and the manuring with
guano, so far from being beneficial, was very injurious--so much
so, that I believe every shilling's-worth of it applied to my
wheat this year, made the crop a shilling worse than if nothing
had been applied; and all ammoniacal manures had the same effect.
It may be asked how I know it was the guano, and not the chemical
manure. In answer to this inquiry, if made, I may observe, that I
supplied two of my neighbours with the chemical manure, and they
applied it without guano on very poor land, and they both assert
they had never such good crops of wheat before; but everywhere in
this neighbourhood, the only good samples of wheat that I saw or
heard of were grown on exhausted soil. This appears to me to be a
strong proof that chemistry has a great deal to learn before it
can adapt its measures to all varieties of seasons, particularly
as it cannot know beforehand how the season may turn out. If
further proof be required of the injurious effect upon grain crops
of ammoniacal manures in general, and of guano in particular, I
may mention that in another field of wheat, sowed on the 21st
December, and which did not come up until the frost broke, in
March (the previous crop having been Swedes), the blade was so
yellow and the plant altogether so small and sickly in appearance,
that I had it manured with a water-cart from a cesspool in April.
This appeared to produce a wonderful improvement immediately, as
the plant assumed a deep green and grew very fast, but when it
ought to have shot, the heads seemed to stick in the sockets, the
blade and straw became mildewed and made no progress in ripening.
It was not fit to cut for three weeks after the experimental
field, although it was an early white wheat, and the result was a
miserable crop--far worse than the experimental field. The
instance of injury from the use of guano, I had from a neighbour,
who told me he had sowed a patch of oats with it, and that they
never ripened at all, and that he was compelled to cut them green
as fodder for his cattle. I had a striking proof this season of
the much lower temperature required by oats than wheat, when
strongly stimulated by manuring. I had gathered an ear of wheat
and a panicle of oats the previous season, which seemed to me to
be superior varieties; and that they might have every chance, I
dibbled them alongside each other in my garden, and determined to
manure them with every kind of manure I could procure, as I had an
idea that it was not easy to over-manure grain crops, if all the
elements entering into the composition of the plant were applied
in due proportion to each other, and I also wished to ascertain
whether wheat and oats would thrive equally well with the same
sort of manuring. I accordingly limed the land soon after the
wheat came up, and in March I applied silicate of soda, sulphate
of magnesia, gypsum, common salt, and nitrate of soda. A fortnight
after this I applied guano, then bones dissolved in sulphuric
acid, then woollen rags dissolved in potash (the two latter in
weak solution); and the consequence was, that I don't think there
was a single grain in the whole parcel--at least I could not find
one--the straw was no great length, and the blade much discolored
with mildew, whilst the oats were seven feet high, and with straws
through which I could blow a pea, and large panicles, although
the oat was not particularly well-fed. The inference I have drawn
from these experiments is, that as far as is practicable the
manuring should be adapted to the temperature, but as this is
obviously impossible in a climate like ours, the only way is to
rather under than over manure, and to apply no ammoniacal manure
to the wheat crop, or at all events very little; for although
guano was beneficial to wheat when used in conjunction with
silicates, &c. &c. in 1844, yet the injury it did in 1845 may very
fairly be set against that benefit. I should feel obliged if any
of your readers who may have tried the experiment of manuring
grain crops with guano, the last season (1845) would publish the
result as compared with a similar crop without such manuring. I
feel convinced that such result would be against the use of guano
for wheat in 1845. I am the more confirmed in the opinion that
ammoniacal manures are unfavourable for wheat, by a series of
articles in the "Gardener's Chronicle" on the "Geo-Agriculture of
Middlesex," in which the writer states that land in that county
which in Queen Elizabeth's time produced such good wheat that it
was reserved for her especial use, will now scarcely grow wheat at
all, and when that grain is sowed upon it, the straw is always
mildewed, and the sample very poor; and this is attributed--and no
doubt justly so--to the extensive use of London manure. My crop
was only 32 bushels to the acre of 60 lbs. to the bushel; last
year the crop, as I have said before, was 50 bushels of the same
weight.
* * * * *
_To the same._
CLITHEROE, _7th March_, 1848.
On continuing my attempts to grow wheat on the same land year
after year, I observed that the crop of 1845 was very seriously
injured by the deficient drainage--the old drains having been
destroyed by the subsoil plough. It was therefore necessary to
replace them: they were accordingly put in four feet deep. This
occupied so much time that the season for sowing wheat had gone
by, and the ground was cropped with potatoes, which were got up in
September, and the wheat might have been got in early in October.
But seeing in your paper that sowing too early was not advisable,
and also being carried away by the arguments of the thin-seeders,
I deferred sowing until the middle of November, and then put in
little seed; and the winter proving very unfavourable, when the
wheat was coming up, there was not half plant enough in the
spring, and I hesitated whether to plough up the ground or drill
in barley. I determined to do the latter, which was done on the
18th April, and wheat and barley grew up together, and when cut
and threshed, proved to be equal to 48 bushels to the acre.
* * * * *
LOW MOOR, _31st December_, 1844.