OF ASHES OF SALINE AND
ALKALI PLANTS.
| (A) | ( B) | (C) | (D) | (E) | (F) | |
|---|---|---|---|---|---|---|
| Ash, air-dried plant, %. | 19.37 | 12.03 | 13.81 | 11.61 | 7.99 | 24.18 |
| Potash (K₂O) | 11.42 | 18.53 | 30.11 | 3.30 | 5.78 | 1.61 |
| Soda (Na₂O) | 35.39 | 39.45 | 32.58 | 2.38 | 5.15 | 2.76 |
| Lime (CaO) | 5.75 | 1.36 | 8.70 | 5.25 | 8.05 | 65.66 |
| Magnesia (MgO) | 3.23 | 1.09 | 1.09 | 2.95 | 4.15 | 26.70 |
| Br. ox. of Manganese (Mn₃O₄) | .22 | .16 | .25 | |||
| Peroxid of Iron (Fe₂O₃) | 3.33 | 7.06 | not det’d. | 2.22 | 2.39 | 1.19 |
| Alumina (Al₂O₃) | ||||||
| Silica | 16.24 | 11.81 | 4.00 | 78.73 | 66.79 | .81 |
| Phosphoric acid (P₂O₅) | 2.80 | 3.51 | 5.60 | .83 | 1.25 | .47 |
| Sulfuric acid (SO₃) | 2.64 | 4.93 | 5.90 | 3.20 | 4.52 | .64 |
| Chlorin, percent | 24.33 | 15.30 | 11.00 | 1.40 | 2.13 | .21 |
| Totals | 105.35 | 103.04 | 99.79 | 100.3 | 100.46 | 100.05 |
| Less excess, O: Cl | 5.35 | 3.25 | 2.50 | .31 | .46 | .05 |
| True totals | 100.00 | 99.79 | 97.29 | 100.00 | 100.00 | 100.00 |
- (G) = Shad scale, Atriplex canescens.‡
- (H) = Alfalfa Hay. (Cal.)†
- (I) = Timothy Hay.
OF FORAGE CROPS.
| (G) | ( H) | (I) | |
|---|---|---|---|
| Ash, air-dried plant, %. | 4.23 | 9.85 | 6.15 |
| Potash (K₂O) | 25.17 | 43.72 | 28.80 |
| Soda (Na₂O) | 6.23 | 4.48 | 2.70 |
| Lime (CaO) | 25.97 | 20.51 | 9.83 |
| Magnesia (MgO) | 16.63 | 2.56 | 3.60 |
| Br. ox. of Manganese (Mn₃O₄) | .51 | ||
| Peroxid of Iron (Fe₂O₃) | 5.89 | 2.95 | |
| Alumina (Al₂O₃) | |||
| Silica | 11.94 | 5.87 | 35.00 |
| Phosphoric acid (P₂O₅) | 3.11 | 5.00 | 10.80 |
| Sulfuric acid (SO₃) | 4.93 | 6.92 | 3.90 |
| Chlorin, percent | 2.07 | 10.25 | 5.00 |
| Totals | 100.45 | 102.26 | 99.70 |
| Less excess, O: Cl | .45 | 22.6 | 1.13 |
| True totals | 100.00 | 100.00 | 98.57 |
| † Jaffa, Cal. St’n. Rept. 1894-95, p. 169. | |||
| ‡ Goss, New Mex. St’n. Bull. No. 44; recalculated. | |||
It will be noted that the saltbush hay contains nearly one-fifth of its (air-dry) weight of ash, of which nearly 40% is common salt. It therefore has a distinctly salty taste, and is always moist to the touch, containing-ordinarily over 15% of moisture. It is therefore much liked by stock when fed intermixed with other hay, and thus supplies all the salt needed by cattle. The greasewood is much less liked by stock, and bushy samphire is wholly rejected by them. Comparing with these fleshy plants the ash of the two grasses, the first a world-wide “salt grass,” the other a common grass of the American arid region, we note that not only do they contain much less soluble ash than the saltbushes, but especially much smaller amounts of sodium salts; proving that even when growing in company with the saltbushes on strongly impregnated land, they can repel from absorption these to them useless or injurious salts. But in the case of the “shad scale,” also a “saltbush” of the Great Basin, the ash-content is remarkably low—only about one-fifth of that of its Australian relative—and it differs widely from the latter in having but a very low proportion of soda, and a very high one of lime and potash, approaching in these respects to our usual forage crops; and being also fairly rich in nitrogen, it forms acceptable browsing when other pasture plants are scarce. It therefore does not exert the laxative action produced by the exclusive feeding on the more saline herbages.
The exceptionally high ash-content of the cactus or prickly pear, also given in the table, arises, it will be noted, not from the soluble salts but from the absorption of extraordinarily high proportions of lime and magnesia. Owing probably to the latter substance, and also the oxalate form in which lime is usually found in the cactus tribe, this plant when used as forage is also somewhat laxative.
Altogether, this table offers remarkable examples of wide differences in the kind and amount of ash ingredients absorbed by plants growing upon similar soils and under identical climatic conditions; indicating a selective power which no merely physical theory of soil-action in plant growth can explain.
Injury to Plants from the Various Salts.—The early observers, especially Contejean, were predisposed from their observations of lime on vegetation to ascribe the action of salt upon marine vegetation to the sodium component. But the wide differences in the effects of different sodium compounds, notably of common salt and Glaubers salt, led some to the conclusion that the acidic ingredients are the chief determining factors. Moreover, it was soon found that a single salt is more injurious than a mixture of several, such as sea water. This also led to the inference that the varying degree of dissociation of these salts essentially influences the effects.