Fig. 89.—Salt-Grass—Distichlis spicata
(L.) Greede.
Relative Tolerance of the Different Species.—The following table shows in systematic order the tolerance of the several plants discussed above, for the different salts, so far as the data available permit. The column marked optimum shows under what proportions of salts the plants grew in about equal luxuriance, therefore under, apparently, the most favorable conditions. Both above and below the proportions mentioned in that column, the luxuriance (size) and (usually) the abundance of the plants was less; showing that while excessive amounts of salts depressed their welfare, yet they also suffered when the proportions dropped below a certain point. Whether this was partly or wholly the result of competition with other plants, is an unsettled question.
TABLE SHOWING MAXIMUM, OPTIMUM, AND
MINIMUM OF SALTS TOLERATED BY EACH OF
THE SEVERAL ALKALI PLANTS.
| Pounds Per Acre in feet. | |||
|---|---|---|---|
| Optimum. | Maximum. | Minimum. | |
| Total Salts. | |||
| Bushy Samphire | 494,320 | 494,520 | 135,060 |
| Dwarf Samphires | 441,880 | 441,880 | 441,880 |
| Alkali-heath | 281,960 | 499,040 | 3,720 |
| 64,300 | |||
| Cressa | 281,960 | 281,960 | 161,160 |
| Saltworts | 130,000 | 153,020 | 3,720 |
| Greasewood | 58,560 | 58,560 | 2,400 |
| Tussock-grass | 49,000 | 499,040 | 49,000 |
| Carbonate (Salsoda). | |||
| Tussock-grass | 23,000 | 44,460 | 3,040 |
| Alkali-heath | [202]19,590 | 19,590 | 680 |
| 680 | |||
| Greasewood | 18,720 | 18,720 | 1,280 |
| Dwarf Samphires | 12,120 | 12,120 | 2,200 |
| Saltworts | 10,480 | 12,120 | 1,120 |
| Cressa | 5,440 | 5,440 | 680 |
| Bushy Samphire | 4,800 | 4,800 | 1,500 |
| Chloride (Common Salt). | |||
| Bushy Samphire | 212,080 | 275,160 | 56,800 |
| Dwarf Samphires | 125,640 | 125,640 | 125,640 |
| Saltworts | 39,760 | 52,900 | 1,040 |
| Cressa | 20,840 | 20,840 | 5,760 |
| Alkali-heath | 10,180 | 212,080 | 1,040 |
| 5,760 | |||
| Tussock-grass | 6,200 | 172,800 | 3,530 |
| Greasewood | 3,680 | 3,680 | 160 |
| Sulphates (Glauber’s salt). | |||
| Dwarf Samphires | 314,040 | 314,040 | 314,040 |
| Bushy Samphire | 277,640 | 277,640 | 50,080 |
| Cressa | 275,520 | 275,520 | 134,880 |
| Alkali-heath | 275,520 | 323,200 | 1,560 |
| 34,530 | |||
| Saltworts | 44,160 | 104,040 | 1,560 |
| Greasewood | 36,160 | 36,160 | 960 |
| Tussock Grass | 19,640 | 323,200 | 19,640 |
APPENDICES.
APPENDIX A.
DIRECTIONS FOR TAKING SOIL SAMPLES.
ISSUED BY THE CALIFORNIA EXPERIMENT STATION.
In taking soil specimens for examination by the Agricultural Experiment Station, the following directions should be carefully observed; always bearing in mind that the examination, and especially the analysis, of a soil is a long and tedious operation, which cannot be indefinitely repeated.
First.—Do not take samples at random from any points on the land, but consider what are the two or three chief varieties of soil which, with their intermixtures, make up the cultivable area, and carefully sample these, each separately; then, if necessary, sample your particular soil, noting its relation to these typical ones.