Essays in Natural History and Agriculture

by Thomas Garnett

CLITHEROE, October 5th, 1843.

SIR,—I PROMISED to send you some details of my attempt to grow wheat on the same soil year after year. These I now forward, and hope they may prove interesting. I was led into these experiments by reading Liebig's book on the "Chemistry of Agriculture;" for, assuming his theory to be true, it appeared to me to be quite possible to grow wheat on the same land year after year; as, according to that theory, the carbon, oxygen, and hydrogen, which constitute the great bulk of all cereal crops (both grain and straw), are supplied in abundance from the soil and atmosphere (or perhaps, to speak more correctly, from the latter), and we have only to supply those inorganic substances, which, however numerous, form but a small part of the whole weight of the crop. With the view of testing this theory, and hoping that I might be able to find out what were the elements which built up and cemented the carbon, oxygen, and hydrogen together—or, in other words, which constituted fertility—I begun, in the autumn of 1841, to experiment on a field which had been exhausted by a succession of crops, and which had just been cleared of one of oats. I chose an exhausted field in preference to any other, as the only one in which I could test the truth of the theory. It was very foul, being full of couch grass and weeds of all kinds. It was ploughed up and hastily picked over, for the season was so unfavourable for cleaning the land (from the great quantity of rain that fell) that I was almost induced to abandon the experiment. Previously to sowing the seed, one-fourth of the field was manured with a compost of night-soil and coal-ashes, at the rate of forty tons to the customary acre (7840 yards); the remaining three-fourths having the seed put in without any manure whatever. The winter was very unfavourable for the plants in our cold wet soil, and in the unmanured part of the field many of them perished, and those that survived made very little progress, from having no stimulus at the roots. Thinking it desirable to apply my experimental manures in moist weather, I waited until the 6th May, when I treated that part of the field which had not been manured (three-fourths of the whole) in the following manner. I applied guano to one-fourth, at the rate of two hundredweight to the statute acre, and the same weight of nitrate of soda over another fourth, leaving one-fourth entirely without manure. The wheat manured with the guano and nitrate of soda grew vigorously, and the ears, more particularly in the part manured with guano, were the finest I had ever seen, but when it came to ripen it shrivelled in the ear, and the sample was very indifferent; the soil being evidently deficient in some property necessary for perfecting the grain. The crop also suffered much from the depredations of the birds.

The portion manured with night-soil produced
to the statute acre 32 bushels of 60 lbs. each.

Guano " " 27 " " "
Nitrate of Soda " " 27 " " "
Unmanured part " " 19 2/3 " " "

I give these details to show that the land was in an exhausted state previous to the commencement of the experiment I am now about to detail. After the crop of 1842 was reaped, the land was immediately ploughed up, and the season being very favourable, it was tolerably well cleaned, and the seed was sown (without any manure) about the first week in October. After the wheat came up, it was manured with a dusting of one hundredweight of guano, over the entire field (about one acre, three roods), to keep the plants alive through the winter. In the spring, being divided into three portions, it was manured with the same number of experimental manures, which were furnished to me by Mr. Blyth, of Church, near Accrington, who also analyzed the soil and subsoil for me. These manures were applied about the 10th of April, and the experiment was still further varied by covering a portion of each division with guano a fortnight afterwards, at the rate of two hundredweight to the acre, but all the manure applied to the crop, including the hundredweight of guano put on in the autumn, did not exceed 6 1/2 hundredweight. The crop, which was a very thin one in the spring, improved so much by the application of these manures, that when it came into ear, it was allowed by all who saw it to be the best in the neighbourhood; but the heavy rains of July caused it to lodge in the best part of the field, and there it was attacked by rust, and the sample was very indifferent. In addition to this drawback, there being very little wheat grown in the neighbourhood of the town, and this being much earlier than any of the other fields, was attacked by the birds as soon as the grain was formed in the ear. Notwithstanding all the efforts made to prevent them, they continued feeding upon it until it was cut; and it is a very moderate estimate of the damage, to say that they destroyed one- fourth of the crop throughout the field. That part of the field covered with manure (No. 1) being the earliest, suffered most. There were patches of several square yards where there did not appear to be a single grain left; and wherever the birds took a grain from the middle of the ear, when in the milky state, the grains on each side of it appeared to grow no more, but shrivelled up in the ear.

I have little doubt that in this portion of the field one-third of the crop was destroyed. All this seems to reduce the experiment to little more than guess-work; and it will, probably, be very difficult to persuade those who did not see the field when it was cut, to credit this report of the devastation made by the birds; even when they are told that Clitheroe is a town of 7,000 inhabitants, and probably as many sparrows, and that apparently they were all assembled to feed in this field; and they became so accustomed to the good living they found there, that even when our neighbours' wheat was fit to eat, they continued to favour this field with their visits in preference to going elsewhere. I estimate the damage on No. 1 at one-third, No. 2 at one-fourth, No. 3 at one-fifth; this was later than the others, and suffered more from rust than birds.

The following are the results:—From 3,060 yards manured with No. 1, there were obtained 1,042 lbs. of wheat, or 27 1/2 bushels of 60 lbs. each to the statute acre; if we add one-half to this, as we assume that one-third was destroyed by the birds, it will give 41 1/4 bushels to the statute acre. The weight of straw from this portion was 188 stones 5 lbs., 14 lbs. to the stone. From 2,856 yards manured with No. 2, 962 lbs. of wheat were obtained, and 155 stones 9 lbs. of straw; this is equal to 27 1/4 bushels per acre, or with one-third added, for estimated damage, it is equal to 36 bushels per statute acre. From 2610 yards manured with No. 3, there were 1,067 lbs. of wheat, and 211 stones 7 lbs. of straw, or 33 bushels to the statute acre, to which if we add one-fourth, according to the estimate of damage, it will be equal to 41 1/4 bushels per acre. It will be observed that this portion yielded a far greater weight of straw per acre than either of the others, and from the sort of manure applied, it was expected that this would be the case.

No. 1 yielded straw at the rate of 297 3/4 stones per acre. " 2 " " " " 246 3/4 " " " 3 " " " " 392 1/3 " "

Many people may feel inclined to say, that all these apparent data are mere guesses, and that a crop may be made into anything one likes, if they assume so much for damages; but, fortunately, it is not all guess-work. I have stated previously that I covered a part of each division with guano a fortnight after the application of the manures in April, intending to see what advantage was obtained by the use of it; but, owing to the depredations of the birds, the portions of the first and second divisions manured with guano were not kept separate from those which were left without guano; but the third being later, and, therefore, not so much injured by them, gave me an opportunity of ascertaining the effect. I measured off a land which had been so manured, and reaped and thrashed it out separately. From this land of 100 yards long and 10 feet wide (3,000 square feet), there was obtained 220 lbs. of wheat, or 53 bushels of 60 lbs. per statute acre; and this was far from being the best portion of the field. I don't mean that it was not the best portion of the crop, but I mean that the soil was not so good there as it was in other parts of the field; as I have before stated, in the best part of the field the crop was spoiled by being lodged by the rain, and subsequently attacked by rust.

I communicate this to you, in the hope that the publication of it in your paper maybe the means of stimulating others to try the same experiments. It is not too late yet to try for the next year's crop, and I have no doubt that Mr. Blyth will be happy to supply both material and information to any who may require them from him. It is the duty of everyone to promote the advancement of agriculture; and this is my contribution towards it. I have not yet done, for I have sown the same field with wheat again, and hope, with a favourable season, to reap a still more abundant crop next year.