CHAPTER XX.

[7]In this, as well as the generality of forms, the smoother and larger growth indicates cultivation, manuring will sometimes make the difference.

Now, it appears to us that the descendants of the two types,Trifolium pratenseandT. medium(seePlate) form the basis of the red or broad-leaved clover on the one hand, and the perennial or cow-grass clover on the other; whilst the market varieties have, perhaps, been modified by climate, soil, and probably hybridization with other sorts. It may, indeed, be that, after all, the plants described inchapter XVII.as two distinct species are only varieties, for though the common form ofT. pratensegrows everywhere on mixed soils, the more sandy positions, as the sandstones connected with the coal in South Wales, offer a greater abundance of theT. medium; and, from experiments conducted with seed of this latter obtained from near Swansea, Glamorgan, and sown on forest marble clay of the Cotteswolds, we certainly obtained plants differing very much from the typical form ofT. medium, and assuming the usual broad-leaved clover variations.

Here, then, is opened up a curious subject for inquiry, which the history of the seed trade as it relates to clover-seed may tend in some measure to elucidate. Some few years agoT. pratenseandT. mediumwere advertised as on sale by most seedsmen; in fact, the latter was the name by which what is now called cow-grass clover was known. Now, however, it is doubtful if any seedsman would pretend to send out theT. medium; but the labelT. pratense perennehas been substituted for it.

Sinclair’s figure of “Trifolium medium, marl-clover, cow-grass,” in the “Hortus Gramineus Woburnensis,” facing page 141, is scarcely a true form of the plant, as its more or less emarginate leaflets incline to the form ofT. pratense; and yet, at the time this author wrote, even this was doubtful.T. mediumwas difficult to obtain, as he says, “All the seeds and plants I have had for this (except that from Messrs. Gibbs & Co., which proved to be the present plant—T. mediumof Sinclair) have turned out only two-year lived plants, or never exceeding three, though cultivated on various soils.” We have repeatedly written for seed, and ten years ago were always supplied with samples so labelled; but in no case did we get it. Latterly seedsmen honestly confess that they have not the seed, but can sendT. pratense perenne.

Now, that this latter is merely a variety of the broad-leaved clover there can be but little doubt; still the fact that it is usually more perennial in its habit is of importance. We may easily understand why it should be so, if we consider that the common broad-leaved clover in its cultivation is so much earlier than the cow-grass form, so that this enables two cuttings of the former to be made in one season, two crops of hay being taken very commonly indeed; and as the plant gets well in flower before it is cut the first time, and seed is saved from the second crop, a more exhaustive plan for the crop itself or its future perennial powers could hardly be brought about. The cow-grass clover, however, is a fortnight and more later, which renders it difficult to cut two crops; and so its method of growth is not so exhaustive. We know that the common wild clover is said tolast only two years, but with constant depasturing we see no reason why the same roots should not send up herbage for five or even ten years.

However theoretical such inquiries may be deemed, yet it must be confessed that they are of great practical importance; for, if a plant has a tendency to run into varieties, it makes it daily more difficult to get its seed true to sort; and if we are liable to have a sample, part of which may be less hardy or part more tardy in its development, it follows that much of it may never arrive at maturity, whilst if it does, as the crop will be uneven, it can never be reckoned upon for so good a yield.

Much of the variable nature of the sorts which we observe in a clover-field may be the result of the mixing of seeds from different and distant localities: if so, it is much to be regretted. But this only tends to show us how important it is that seed should be grown with care, to which end, as regards clover-seed, we sadly want some well-conducted experiments on different varieties, especially of a wild native plant, with a view to obtain a sample with good, permanent, and even qualities. In fact, the question of true of sort is altogether different from that of purity of sample; but that very serious mischief arises from the want of the latter will be discussed in another chapter.

Besides the clovers proper, there are many native plants of the same natural order that have been found useful as fodder: these it is now proposed to comment upon, premising that as we have had them all under cultivation, we are enabled to discuss their merits from a practical point of view.

Of these, the following is a list of the genera:—

I.Ulex.—A spinous shrub.II.Anthyllis.—Flowers in a dense head, with white expanded calyces.III.Lotus.—Flowers in lax heads; pod straight, many-seeded.IV.Medicago.—Flowers various; pod spirally twisted.V.Melilotus.—Flowers in spikes, drooping to one side; pod straight, few-seeded.VI.Onobrychis.—Flowers in spikes, drooping; pod wrinkled, one-seeded.VII.Vicia.—Flowers single or spicate in the axils of the leaves; pod straight, many-seeded.VIII.Lathyrus.—Flowers one or many on long footstalks.

A genus of shrubby, spinous, pea-flowered plants,by far too common on our sandy heaths and wild hilly places, with varieties occupying wet commons.

We possess, according to authors, some two or three native species; but we incline to the belief that they are only varieties of the commonU. Europæus, of which these seem to be large and dwarf forms. This plant, under the name of furze or gorse, has been from time to time highly extolled as a fodder plant, and machines have been invented for bruising its complicated spines; but although it will doubtless grow where scarcely anything else can be got to succeed, yet, taking into consideration the expense attendant upon its growth and utilization, and the low feeding powers which it possesses, we cannot at all agree in recommending its general use. It is, however, but right here to say that articles are from time to time inserted in such journals as theAgricultural Gazette, the authors of which advocate the growth of furze as an agricultural plant, and highly extol its feeding qualities; still, as our own experience would lead us to conclude that as even young stock scarcely hold their own upon this plant, we cannot recommend it as possessing very valuable properties.

TheAnthyllis vulnerariais well distinguished in its young state from its sometimes entire lancet-shaped, at others pinnate leaves, growing close to the ground. These are usually clothed with long hairs, and it has expanded downy calyces, when full grown. In its young condition it has been very much extolled for sheep pasturage, while its hay is said to be abundant and nutritious, though grown on the very poorest of soils. That it will grow more uprightwhere sown, one plant drawing up another, we know from experience, but we have little faith in any very superior qualities being found in plants that can grow so well under extremely poor conditions of soil; still it is just possible that its herbage may improve in quantity and quality by liberal treatment; yet we must conclude that, as we already possess much better plants for growing on better soils, we do not think much can be gained by its cultivation.

As a plant for hay it will yield a good cut, but its extreme hairyness and general want of what the farmer calls “proof” will never allow this plant to be extensively grown.

This plant is well known by its loosely-packed heads of bright yellow flowers, which are succeeded by long slender pods, dark-coloured or even black when ripe, and not inaptly likened to a crow’s foot; and hence the name “Crowsfoot” which it commonly bears. We have three species, as follow:—

1.Lotus corniculatus—Common Bird’s-foot Trefoil—is common, especially in dry meadows, in which its herbage is duly appreciated by sheep and cattle, if one may judge from the pertinacity with which it is kept down. It is no bad adjunct to the rick. We are so convinced of its value as always to recommend its use in the laying down of light land for permanent pasture, and a little seed sown in old meadows after a dressing of rubbish—old mortar, town refuse, &c.—will tend greatly to the improvement of the herbage.

2.Lotus tenuis—Slender-leaved Bird’s-foot Trefoil—is, perhaps, only a variety of the former; it is,however, smaller in all its parts, and, though a denizen of stiff soils, occurs chiefly in a wild state on the margins of fields and on hedge-banks. It might be employed under the same circumstances as theL. corniculatus, especially in thin clay-beds on upland brashes; but it hardly possesses such good qualities.

3.Lotus major—Larger Bird’s-foot Trefoil—is much larger in all its parts than the other species. It occurs in moist situations, about bushes in wet land, in ditches, watercourses, and damp places generally. We have experimented upon the growth of this plant in artificial meadows, and from the size which it attains quite early in summer, and the quantity of wholesome keep it is capable of affording, we are disposed to think well of it as an occasional shifting crop, or it might be well combined with rye-grass in deep stiff soils.

This genus is principally distinguished fromTrifoliumby its twisted seed-pods, which in theMedicago maculata(Spotted-leaved Medick) form quite a spiral coil, ornamented with a double fringe of stiff spines. This plant is now becoming general as an agrarian weed, having been greatly spread, owing to its intermixture with foreign seeds of different kinds.

The agricultural species are:—

Medicago lupulina—Yellow Sickle Medick.—“Hop trefoil” of the farmer, but not of the botanist, who gives this name to theTrifolium procumbens(whichsee). From this latter the medick is easily distinguished by its heads of naked, blackened, incurved seed-vessels. As an agricultural plant it is of great value, especially in mixtures called “seeds.” It is agood adjunct to rye-grasses and common clovers, especially on light soils; but on good strong land which will bear a full crop of broad-leaved clover it would be mostly smothered out, and, if not, as we think it is properly held to be less nutritious than clover, its use is not recommended where first-rate clover crops can be grown.

We have seen this trefoil grown with sainfoin to great advantage, as it yields a tolerable crop for the first two years, and then declines, just as the sainfoin has got possession of the soil.

2.Medicago sativa—Lucerne—is a perfectly perennial plant, which, though not so much grown in England as it deserves, yet scarcely needs description; however, its purple flowers and smooth twisted seed-pods serve to distinguish it from the rest of the genus. We have grown this plant upwards of a foot high by the 1st of May, and taken no less than three cuttings of a good succulent herbage in one season. These qualities point out lucerne as an excellent green-food plant, for which purpose we should always, where practicable, recommend that at least a patch should be grown near the stable, as there is reason to believe that its alterative effects upon the horses are of a most salutary kind. It should be cultivated in drills of from 15 to 18 inches apart; and, if properly weeded and not let get too old before cutting, it will last for many years with an occasional dressing of manure.

We once had a patch one half of which was purposely neglected by way of comparison with the other half, which was well cared for; that portion left to itself yielded but poor crops, and almost disappeared at the end of four years, whilst the other portionscarcely began to decline after ten years. This remark applies with full force to all the green-food crops of this order. Weeding early, mowing when cut, and an occasional top-dressing, would increase the durability of all the perennial species.

These are pea-flowered plants, with ternate leaves, and spikes of flowers drooping to one side: it is named frommel, honey, in allusion to its flavour, and the genusLotus, by which we may understand it to be a sweet-scented lotus-like plant. We have two native species, distinguished thus:—

Melilotus officinalis, an annual, with yellow flowers.

M. leucantha, a biennial, with white flowers.

Of these we may conclude that the flavour, which is like that of theAnthoxanthum odoratum—sweet vernal grass—is too strong and bitter to allow of its being recommended for culture alone; but we are inclined to think that, if grown in small quantity with seeds, or if a separate patch be cut and arranged sandwich-wise in the seed-rick, the melilots would give that sweet flavour which seems to be the principal cause of the superior qualities and sweetness of natural meadow as compared with artificial grasses.

Seeds have been forwarded to us of what is named “Cabool Clover,” and another packet labelled “Bokhara Clover,” both of which appear to belong to theM. leucantha, though certainly of a larger form than our native species, and probably consisting of theM. leucantha major. This latter must be cut young if used as recommended, as it soon gets woody. A correspondent of the Royal Agricultural Society has recently recommended the full-grown plant for paper-making;and, if of value for this purpose, we can affirm from experience that a large yield can be got from soils of a very inferior quality, as our experiments on its growth have been made on a very stiff and poor bed of forest marble clay.

Sainfoin, or “holy fodder” of the French, is distinguished by its brilliant spike of pink variegated flowers, which droop to one side, its winged leaves of from six to eight pairs of oval leaflets, which are entire, that is, undivided at the margin, and its short, rounded, wrinkled, and spinose seed-vessels. The forms in cultivation are—

Onobrychis sativa—Common Sainfoin.Onobrychis sativa, var.bifera—Giant Sainfoin. Of these the former has the preference in England, whilst the latter is much grown in France. Our experiments with both lead us to conclude, that although the former flowers but once and the latter twice in the season, theO. sativastill gives the greatest amount of food, as the second crop of the giant sort is usually poor and straggling, with but little leaf; while the common sort sends up a thick growth of leaves after being cut.

TheO. sativa biferais but a variety of theO. sativa, as by long continuance of growth from the same seed in this country it reverts to the common form; and hence the giant sort should be frequently renewed from an imported stock. Sainfoin has been much cultivated on calcareous soils, more especially on the free-stones of the oolite rocks, and on the chalk, off which formations it is scarcely known, except on some calcareous sands in the eastern counties. In the limestoneand chalk districts sainfoin is grown as a permanent crop, and formerly lasted six or eight years. In the eastern counties the little there grown is by way of a shifting crop, in the same place and manner as common clover. The permanency of sainfoin is yearly becoming greatly diminished from the circumstance that its seed is so much mixed with that of the burnet,Poterium sanguisorba, var.muricata. To such an extent does this evil occur, that we have examined samples of sainfoin seed in which there were at the rate of from twenty to forty thousand of burnet seed-pods per bushel; and when we consider that these pods have for the most part two ripened seeds, and those of a plant growing so much more rapidly than the sainfoin, we can form some notion how the desired crop is soon smothered and overpowered by the burnet, which at best is but a rank weed, of no agricultural value; for whatever of good there may be in our ordinary native salad burnet, which is a smaller and more succulent plant, this sticky foreign interloper cannot possibly have any claim to our regard.

The reason why it has gone on so long unchallenged is that the burnet-seed, though of an entirely different shape from the sainfoin, is somewhat of the same colour; and then in their growth both plants have winged leaves, and the difference between the entire leaflets of the sainfoin and the toothed leaflets of the burnet did not at first strike the farmer; now, however, the difference is better understood, and farmers begin to require that the burnet-seed shall be sifted from the sainfoin. This of course will demand the payment of a better price for the better sample, as in the process of sifting many of the smaller sainfoin seedsgo through with the burnet; but this will be well worth a better price, as the larger seeds will undoubtedly tend to produce a better crop.

If, however, there should be any doubt about pure sainfoin seed, we should recommend the decorticated seed being used, as in it the burnet could not possibly escape detection.

As the history of burnet is so important in connection with the sainfoin crop, it cannot be out of place to introduce the following description of this weed:—

TheSanguisorba officinalis(false burnet), as a wild plant, never attains any great size, and as it is a denizen of dry calcareous pastures and broken ground on limestones, and perfectly harmless in its properties in this condition, it is scarcely noticeable as a weed; indeed, it is sometimes recommended for permanent pasture admixture on calcareous uplands. There is, however, a larger form of the false burnet, which is now attracting considerable attention, as being by far too constant an attendant upon sainfoin seed.

This plant is referred by Professor Babington and the Continental botanists to another species, viz.,Poterium muricatum, which is by them distinguished from theP. sanguisorba; but is “usually larger in all its parts” (Bab.), with a larger and more decidedly four-winged fruit. We, however, agree with Bentham in considering this to be a variety only, and, in fact, an agrarian form, induced by its seed being gathered with a crop and treated as a crop plant, so that its larger form may be easily accounted for; and we are not wanting in evidence to show that, under cultivation, theP. sanguisorbagreatly increases in size, while, if left to grow wild, the cultivated form relapsesinto the wilder state. But we incline to think that the agrarian burnet has got into agriculture by being introduced with foreign seeds; and as its introduction seems to have been small at first, it attracted but little notice; for as the leaves both of the burnet and sainfoin were pinnate, the difference that the botanist would observe in the leaflets,i.e.the former being serrate, and those of the latter having an entire margin, would hardly attract the attention of the farmer; however, it soon became so serious a matter that some crops of so-called sainfoin, in their second or third year, presented as much as 90 per cent. of burnet, and as the latter grew taller than the sainfoin, it effectually smothered it out, and in its place supplied a sticky, non-succulent, and innutritious herbage, that made farmers begin to inquire seriously about the seed.

Here, however, as the seeds, or rather the fruits, of both plants were pretty much of the same colour, and both wrinkled, samples of fully half burnet passed muster in the seed-market; and, though these fruits are so different in shape and size, yet we were astonished to find that, during the trial of an action against a seedsman for supplying sainfoin seed containing a large quantity of burnet when good sainfoin seed was paid for, the judge, jury, and most of the farmers present confessed their inability to distinguish them; it becomes, therefore, at this point, a duty to describe the two.

Sainfoin seedFig. 32.

Fig. 32.

Fig. 32arepresents a short wrinkled pea-pod, broad at the back and thin in front, as seen in the sectionb. In the interior is asingle pulse-seed, which is easily freed from its wrinkled shell.

False burnet seedFig. 33.

Fig. 33.

Fig. 33ais a drawing of a fruit of false burnet. The sectionbshows it to be quadrangular, with a wing at each angle, and to possess two seeds in each capsule. The capsules are rather muricated (i.e.furnished with short excrescences, and not regularly wrinkled, like the sainfoin). Now the burnet is easily separable from a sample of sainfoin, as the former readily passes through the sieve; but the objection to sift it may be well understood when the bulk is diminished by the amount of the burnet, and also that of the smaller sainfoin seeds, which pass through at the same time.

The best plan, then, to pursue is to mill the sainfoin seed, in which case its outer covering is removed, and you simply have a sample of kidney-shaped pure seed-like enlarged clover-seeds, in which the burnet may be detected, because it will not mill, but simply gets its wings broken off, so that the wrinkled two-seeded capsule still remains.

Now the fact of the burnet being a two-seeded capsule is most important to be noticed, as, from analyses we have made of dirty sainfoin crops, we have estimated as follows:—

Here, then, we have a large proportion of burnet, surely much more than could be accounted for from the number of capsules, at least we will hope so; but when we consider that the capsule of the sainfoin issingle-seededand that of the burnet istwo-seeded, we may readily conceive how each capsule of the latter may at least grow a single seed, but the best sample of the former could hardly be expected to all come up. Now, as we have as many as 64,000 capsules of burnet in a bushel of sainfoin seed, that × 2 = 128,000 seeds, and when we consider that the burnet grows so much faster than the sainfoin, we have two elements for the success of the former, namely, the certainty of getting its crop, and the equal certainty of smothering out a large proportional of what may germinate of the seeds of the sainfoin.

This matter would not be of such importance if the burnet was equal in point of feeding properties, but it is not so, for whatever quality be in the smaller and more succulentP. sanguisorbaform, theP. muricatumis, on the contrary, hard and woody, and almost useless.

In considering the important question involved in the term “Clover sickness,” we would first direct attention to the fact that crop clover is a derivative plant which has been soforcedthat it is many times larger and more juicy and succulent than the wild plant from which it sprung. Thisderivednature (the propensity, as it were, for fattening) can only be maintained by a continuance from one generation to another of those luxuries to which the cultivated family has been accustomed; hence, then, if seed be brought from a richer soil to a poorer, or from a warmer to a colder climate, we may expect that its plants grown amid barley and drawn up during the summer would have but a poor constitution to withstand the rigours of winter; but can we in such a case say that thelandis clover-sick, that is, sick of growing clover?

Of course the seed here supposed will grow better in one place than in another, as, for example, we have traced some American seed of broad-leaved clover grown by itself in a deep rich soil in the Vale of Gloucester, where the climate is so much milder as to be a fortnight before the elevated land of the Cotteswold Hills and producing an abundant crop; while the same forming part of a mixture of “seeds” with rye-grass and plantain on the hills, the two latterhave taken possession of the soil, and the clover made no progress at all; whilst other seed, under precisely the same circumstances, has done remarkably well.

That there is much reason for these conclusions will be found in the fact that the more seed we import from warmer climates the more difficult is it found to make the land produce a plant; still importation is rapidly on the increase, because warmer climates can produce seed more certainly and in greater quantity than we can at home.

The difficulty of growing from foreign seed increases in proportion to the thinness of the soil and the backwardness of the climate, so that the elevated districts on the stony Cotteswolds just adverted to present, perhaps, more of the so-called clover-sick land than any other of like extent.

The seed of clover, then, has become more and more pampered—more the offspring of large crops from deep alluvial soils under the tropical summer heat of the south of France and the United States, where it is grown as a self-crop and not fed merely on what the corn could not carry away; and so while this enervation, or, if preferred, this civilization, of plant has gone on, we expect its seed all at once to withstand the shock of a lower temperature with constant climatal changes and cutting winds; and if it does not succeed, we say that the land is clover-sick, when, in truth, it is the seed that sickens under these new and trying conditions. As well may we say that the Northern States sicken of the negro, because he there dies out so rapidly, or that the warm south sickens of humanity, because those who are unacclimated sicken and die there.

Another circumstance which has contributed to anincreased difficulty in growing clover on thin soils will be found in the farmer discarding as antiquated the practice of paring and burning, which was formerly the usual preparation for the turnip crop. In a paper on “Paring and Burning,” in the 18th volume of theJournal of the Royal Agricultural Society, Professor Voelcker remarks:—

The ashes produced by paring and burning are especially useful to turnips, and also to other green crops, because they contain a large proportion of phosphates and potash—constituents which, it is well known, favour in a high degree the luxuriant growth of root-crops.

Further, the learned professor closes a most able paper with the following conclusions:—

Paring and burning, instead of being an antiquated operation, is a practice the advantages of which are fully confirmed and explained by modern chemical science.

Paring and burning, to judge from our own experience, had the effect of converting some of the hard limestone brash into lime, in which case it broke up by the influences of air and rain, and so restored the lime and alumina which mostly exist together in limestone, the former of which is quickly lost in thin soils,—so much so, indeed, that not unfrequently the whole depth of soil, even upon a limestone, will often be curiously devoid of lime, which is a necessary ingredient in the constitution of a clover crop.

Again, we should conclude that the operation under discussion, from its decomposing that dark vegetable matter calledhumus, which is always found in large quantities on some of the soils which are called “dead,” from their inability to produce crops, and which often cause astonishment that such black, nice-looking earth should be unproductive. Now thissoil, though it would favour the growth of some species of peat-loving plants, as Ling, Heath, &c., is not suitable for clover, as the wild plant is curiously absent from peaty positions.

Professor Voelcker remarks that “the excess of undecomposed organic matters in soils is decidedly injurious to vegetation. Roots, stems, and other vegetable matters remain buried in the ground for years without undergoing decomposition, and if we attentively study the subjoined analysis of soil in the neighbourhood of Cirencester, well adapted for burning, we shall see how thelime,alumina, andorganic mattermight be beneficially affected by the process:—

The ashes, however, are obtained by burning a thin slice pared from the surface of the land, so that they are derived from surface-soil and vegetable matter, the latter often yielding a sufficient amount of phosphoric acid with which to procure a crop, and, what is all important for us to consider is, that this phosphorus, the alkalies, and lime, are rendered by the burning in a state just fitted for the growth of the plants that are to be grown upon them; whereas,before the process, these ingredients were in a measure locked up, so that plants could not grow for the want of sustenance; not that it was not in the soil, but that it was insoluble. If, then, clover or any other plant had not succeeded, it would have been called “clover-sick.”

The following analysis of vegetable ashes from a field in the neighbourhood of Cirencester will well repay attentive consideration, as illustrating these points:—

Now, that land so burnt and containing such ingredients would, after the process, refuse to grow clovers we cannot at all believe; but we do know that some of the land of a like composition will not grow even a crop of turnips until prepared as described; and though the taking a subsequent barley crop off before the clover would not tend to the improvement of the latter, it will be too often because the barley hastaken all the available manurial matter, so that there is little left for the clover to feed upon. In such cases we have seen the clover saved by top dressing. Paring and burning had also a salutary effect upon the clover crop in the destruction which it wrought to various insect pests, and more especially the wire-worm, which now makes such increasing inroads upon our crops of wheat and barley, and so afterwards in the clover; so that bare patches, often of great extent, will be the consequence in every crop in the rotation. Now, these bare patches in the clover crop are often appealed to as evidence of clover-sickness, whilst we do not at the same time say that land is wheat-sick or barley-sick.

Insects, indeed, are yearly becoming more destructive, not only on account of the difference in the mode of farming, but greatly from the determined destruction of birds. The food of birds is in general very mixed, but at one season of the year, when they are breeding, they are most industrious destroyers of insects; but it is just at this time that they are kept from the crops, exactly when insects are working the most mischief: hence, then, as the exigencies of a small growing family become more and more pressing, birds are driven to feed their young upon seeds, fruits, buds, and other vegetable matters, as unsuitable to build up the constitution of the young bird as bread diet for an infant.

Let, however, our grand birds of prey be encouraged, instead of being shot by the keeper as vermin, or knocked over by the prowling bird-stuffer, in order to be perched up in a box for sale to some Cockney, whowould fain be considered as fond of sport because his “den,” perchance, contains a stuffed owl, hawk, magpie, or some otherspecimen.

On a recent visit to Dorsetshire, on our own farm, we saw a man employed to “keep the birds” from a field where several labourers were engaged barley sowing; and it is quite true that, unless he had been there, the rooks would have as industriously followed the drill as they do the plough; but, as we thought, scarcely to pick up barley in the breeding season, when there was metal more attractive in the recently-hatchedElater obscurus, parent of the wireworm, which were thicker than we ever saw them before, and, doubtless, the disturbance of the soil brought these and two or three generations of wireworms to the surface. Now, we do not hesitate to give as our opinion that this birdkeeper would have done more good to the barley and the succeeding clover crop by picking up a hundred or two of these beetles and destroying them than by blazing away at rooks for a twelvemonth, and this certainly might have been done in an hour or two.

Still, that some soils do get incapable of growing a clover crop is pretty certain; and it may, we think, be equally settled that this does not entirely depend upon their having been exhausted of the ingredients which analysis demonstrates clover to contain, for we certainly have seen clover succeed after the burning of so-called clover-sick land; and though there is reason to think that this result was partially due to the setting free of a fresh supply of manurial ingredients, we are still convinced that the burningout of humus or peaty vegetable matter and the destruction of insects had their share in the induced change.

Still, however much we may suppose that the failure of the clover crop is influenced by the alteration of its constitution as the result of cultivation, the presence of choking weeds, or by the presence of prejudicial ingredients, especially in thin soils, there can be no doubt that the principal cause of the difficulty will be found in the fact that the corn crop with which the clover is grown exhausts the soil, in the most unsparing manner, of the very chemical ingredients which the clover requires.

Thus, if sheep are folded on a crop of turnips, the whole of this crop is converted into a manure at once available for the grain crop, by which it is quickly appropriated and then taken away. Here, then, we may suppose at starting that the clover is half starved; and, with a constitution drawn up in the effort of the plants to obtain a glance of sunshine, and weakened for the want of nourishment, it is expected to bear our inclement winters.

This argument will be made all the clearer if we place side by side the result of the analyses of barley and clovers, and especially if we consider what a quantity of mineral matter is taken in a short time, and by a crop ripening its straw and seed.

Now, if we look at these figures we shall see how much of the mineral matter required for the clover has been previously abstracted by the barley, and if at the same time we reflect that this robbery may, and too often does, co-exist with the other causes which we have instanced as tending to clover-sickness,we should no more call land sick of clover because it will not bear this crop under our exhaustive system of cultivation than we should call a barren sand wheat-sick for refusing to grow corn.

We cannot better conclude this chapter than by quoting the following from Baron Liebig’sLetters on Modern Agriculture, so ably translated by Professor Blyth:—

The simplest peasant has sense enough to see, and all agriculturists agree with him, that clover, turnips, hay, &c., cannot be sold off from a farm without most materially damaging the cultivation of the corn. Every one willingly admits that the sale and exportation of clover, turnips, &c., exercise a detrimental influence on the growing of corn. “Above all, let us take care to have plenty of fodder; the corn crop[146]will then take care of itself.” But that theexportation of cornmay possibly exercise an injurious influence on the cultivation of clover or turnips; that it is, above all, indispensable to restore to the soil the mineral constituents of the corn, to enable the clover or turnip crop to “take care of itself;” in other words, that in order to grow clover, turnip, &c., we must manure the land—this is a notion utterly incomprehensible, nay absolutely impossible, for most agriculturists. For, is not the clover grown for the sake of manure? What advantage, then, would there be if it were necessary to manure again to produce the clover?This clover the farmer expects to grow for nothing.The mutual relations existing in the order of nature between the two classes of plants are, however, as clear as daylight. The mineral constituents of the clover, turnips, &c., and of the corn, form the conditions for the production of the clover, turnips, &c., and of the corn, and they are in their elements quite identical. The clovers, &c., require for their growth a certain amount of phosphoric acid, potash, lime, magnesia,—so does the corn. The mineral constituents contained in the clover are the same as those in the corn,plusa certain excess of potash, lime, and sulphuric acid. The clover draws these constituents from the soil; the cereal plant receives them,—we may so represent it from the clover. In selling his clover, therefore, the farmer removes from his land the conditions for the production of corn. If, on the other hand, he sells his corn, there will be no clover crop in the following year;for in his corn he has sold some of the most essential conditions for the production of a clover crop.—pp. 183-5.

The mutual relations existing in the order of nature between the two classes of plants are, however, as clear as daylight. The mineral constituents of the clover, turnips, &c., and of the corn, form the conditions for the production of the clover, turnips, &c., and of the corn, and they are in their elements quite identical. The clovers, &c., require for their growth a certain amount of phosphoric acid, potash, lime, magnesia,—so does the corn. The mineral constituents contained in the clover are the same as those in the corn,plusa certain excess of potash, lime, and sulphuric acid. The clover draws these constituents from the soil; the cereal plant receives them,—we may so represent it from the clover. In selling his clover, therefore, the farmer removes from his land the conditions for the production of corn. If, on the other hand, he sells his corn, there will be no clover crop in the following year;for in his corn he has sold some of the most essential conditions for the production of a clover crop.—pp. 183-5.

This discussion, then, upon the so-called clover-sickness leads us to adopt the following propositions:—

First. That the larger induced plant of our cultivated clovers has not, as a rule, that perennial constitution of the smaller wild species.

Second. Even its induced habit is much deteriorated by transportation under adverse climatal circumstances.

Third. The seed itself is often full of weeds, which, by gaining the mastery, kill out the young clover plant.

Fourth. This effect is enhanced by growing clover with barley, in which, if not smothered, it must become weakened.

Fifth. We ought not to expect to grow clover where we have taken away the necessary substances for its growth in the corn crop.

That clover crops are often very full of weeds every farmer must be fully aware, but few among them have used sufficient penetration to have discovered the source of most of the weed growth, not only in clovers, but in other crops: how much, then, may they be expected to be astonished if told that they cultivate weeds by sowing their seeds as carefully as they do those of their crops, and that they pay the same price for weed as for crop seeds!

In the spring of 1859 we published the results of some analyses of the weed admixtures in several samples of different kinds of clover seeds, which we annex (table 1, p. 149), adding to them some further results obtained during the present spring, 1863, by way of comparison.

This presents a formidable array of figures, as it shows how much of more than mere harmless matter is purchased and sown instead of good seed; and the fact of the mischief likely to accrue from putting so many enemies in the place of friends will become all the more plain by a careful study of the next table (No. 2, p. 150).

Now, in order to make this part of our argument still more complete, we add another table (No. 3, p. 150), intending to show the number of weed plants absolutely separated from a single squareyard of old seeds taken from a field on the great oolite rock.

These three tables show us not only the fact that the farmer sows weeds with his crop, but, as will be seen fromtable 2, quite enough of these in some cases to stock the land,—how effectually, indeed, may be seen fromtable 3, where in arable land we find no less than forty-six plants other than the crop, and mostly of those species whose seeds will be traced in dirty samples. To further show that clovers and their mixtures with grasses called “seeds” have theirown peculiar weeds, we subjoin one other table of the species of weeds observed in three kinds of seed crops as under:—

1. Old clover and common rye grass (second year).

2. “Old seeds,”—clover, trefoil, common and Italian rye grasses (second year).

3. New seeds, clover and rye grass (first year).

No. 1 examined on August 31; 2 and 3 on the 24th September, 1859.

Back to Index Next