At Bechelbronn, the farm of the celebrated Boussingault, the average yield is nearly eleven tons per acre, but occasionally over fourteen tons is obtained. Donoil, a farmer of Bailiere, in the department of Haut-loire, states that he fed sheep exclusively on the tops and tubers of this plant, and that he estimated his profits at £23 per hectare (£9 3s. 4d. per acre). The soil was very inferior. Donoil terms it third-rate, and it does not appear to have been manured even once during the fifteen years it was under Jerusalem artichoke. I fear our artificial manure manufacturers will hardly look with a favorable eye on the advent of a crop into our agriculture which can get on so well without the intervention of any fertilising agents. Indeed, several of the French writers state that little or no manure is necessary for this plant. But this can hardly be the case; for it is evident that a crop which, according to Way and Ogston, removes 35 lbs. of mineral matter per ton from the soil, or three times as much potash as turnips do, must certainly be greatly benefited by the application of manure. And I have no doubt but that the Jerusalem artichoke, if well manured and grown in moderately fertile soil, would produce a much heavier crop than our Continental neighbors appear to get from it.
4th. The Jerusalem artichoke may be cultivated with advantage in places where ordinary root-crops either fail or thrive badly. In such cases the ground should be permanently devoted to this crop. Kade gives an instance where a piece of indifferent ground had for thirty-three years produced heavy crops of this plant, although during that time neither manure nor labor had been applied to it. In Ireland the potato has been grown under similar circumstances.
The nutritive constituents of tubers of the Jerusalem artichoke bear a close resemblance in every respect, save one, to those of the potato. Both contain about 75 per cent. of water, about 2 per cent. of flesh-forming substances, and 20 per cent. of non-nitrogenous, or fat-forming and heat-giving elements. In one respect there is a great difference—namely, that sugar makes up from 8 to 12 per cent. of the Jerusalem artichoke, whilst there is but a small proportion of that substance in the potato.
The large quantity of sugar contained in this root is no doubt the cause of its remarkable keeping properties in winter, and it also readily accounts for the avidity with which most of the domesticated animals eat it.
On the whole, then, I think that the facts I have brought forward relative to the advantages which the Jerusalem artichoke presents as a farm crop, justify the recommendation that it should get a fair trial from the British farmer, who is now so much interested in the production of suitable forage for stock.
| COMPOSITION OF (DRY) JERUSALEM ARTICHOKE | |
| Albuminous matters | 4·6 |
| Fatty matters | 0·4 |
| Starch, gum, &c. | 19·8 |
| Sugar | 69·5 |
| Fibre and ash | 5·7 |
| ——— | |
| 100·0 | |
The Potato, regarded from every point of view, is by far the most important of the plants which are cultivated for the sake of their roots. Its tubers form the chief—almost sole—pabulum of many millions of men, enter more or less into the dietary of most civilised peoples, and constitute a large proportion of the food of the domesticated animals. The great importance of this plant, arising from its enormous consumption, has caused its composition to be very minutely studied by many British, Continental, and American chemists. With respect to its nutritive properties, the least favorable results were obtained by the American chemists, Hardy and Henry, and the most by the European chemists.
The flesh-forming principles vary from 1 per cent., as found by Hardy, to 2·41 per cent., the mean results of the analyses of Krocker and Horsford. The proportion of starch in different varieties of the potato also varies, but not to the same degree as the nitrogenous principles. In new potatoes, only 5 per cent. has been found; in ash-leaved kidneys, 9·50 per cent.; and in different kinds of cups, from 15 to 24 per cent. The amount of starch is also influenced by the soil, the manure, the climate, and the various other conditions under which the plant is developed. The proportion of starch increases during the growth, and diminishes during the storage of the tubers.
Dr. Anderson is the most recent investigator into the composition of the potato; the chief results of his inquiries are given in the following table:—
| ANALYSIS OF THE POTATO BY DR. ANDERSON. | ||||||
| Regents. | Dalmahoys. | Skerry-blues. | White Rocks. | Orkney Reds. | Flukes. | |
|---|---|---|---|---|---|---|
| Water | 76·32 | 75·91 | 76·60 | 75·93 | 78·57 | 74·41 |
| Starch | 12·21 | 12·58 | 11·79 | 12·77 | 10·85 | 12·55 |
| Sugar, &c. | 2·75 | 2·93 | 3·09 | 2·17 | 2·78 | 2·89 |
| Flesh-formers | ||||||
| soluble | 2·16 | 2·10 | 1·90 | 1·88 | 1·48 | 1·98 |
| insoluble | 0·21 | 0·15 | 0·16 | 0·24 | 0·21 | 0·20 |
| Fibre | 5·53 | 5·21 | 5·41 | 5·55 | 5·93 | 6·71 |
| Ash | 0·88 | 0·81 | 0·94 | 1·04 | 0·98 | 0·98 |
| 100·06 | 99·69 | 99·89 | 99·58 | 100·80 | 99·72 | |