In alkali lands, as in others, the natural plant-growth affords such means, both as regards the quality and quantity of the saline ingredients. The most superficial observation shows that certain plants indicate extremely strong alkali lands where they occupy the ground alone; others indicate pre-eminently the presence of common salt; the presence or absence of still others form definite or probable indications of reclaimability or non-reclaimability. Many such characteristic plants are well known to and readily recognized by the farmers of the alkali districts. “Alkali weeds” are commonly spoken of almost everywhere; but the meaning of this term—i. e., the kind of plant designated thereby—varies materially from place to place, according to climate as well as the quality of the soil. It is obvious that if these characteristic plants were definitely observed, described and named, while also ascertaining the amount and kind of alkali they indicate as existing in the land, lists could be formed for the several regions, which would indicate, in a manner intelligible to the farmer himself, the kind and degree of impregnation with which he would have to deal in the reclamation work; thus enabling him to go to work on the basis of his own judgment, without previous chemical examination.
A study of the lands of California having this purpose in view, was undertaken in the years 1898 and 1899 by the California Station; but lack of funds prevented its prosecution beyond the ascertainment of those plants the abundant occurrence of which prove the land to be irreclaimable without the use of the universal remedy, viz, underdrainage, which on the large scale is usually beyond the means of the land-seeker. The botanical field work and collection of soil samples was carried out by Mr. Jos. Burtt Davy; the chemical work, as heretofore, being done by Dr. R. H. Loughridge. The results here reported are therefore essentially their joint work. It is hoped that in the future, a more comprehensive study and close comparison of the native vegetation with the chemical determination of the quality and kind of alkali corresponding to certain plants, or groups of plants, naturally occurring on the land, may enable us to come to a sufficiently close estimate of the nature and capabilities of the latter from the native vegetation alone, or with the aid of test plants purposely grown, for the farmers’ purposes.
Plants Indicating Irreclaimable Lands.—The plants herein-after mentioned and figured are, then, to be understood as indicating, whenever they occupy the ground as an abundant and luxuriant growth, that such land is irreclaimable for ordinary crops, unless underdrained for the purpose of washing out surplus salts. The occurrence merely of scattered, more or less stunted individuals of these plants, while a sure indication of the presence of alkali salts, does not necessarily show that the land is irreclaimable.
The plants which may best serve as such indicators in California are the following:
Tussock-grass (Sporobolus airoides Torr.), [Fig. 82].
Bushy Samphire (Allenrolfea occidentalis [Wats.] Ktze.), [Fig. 83].
Dwarf Samphire (Salicornia subterminalis Parish, and other species), [Fig. 84].
Saltwort (Suaeda torreyana Wats., and S. suffrutescens, Wats.), [Fig. 85].
Greasewood (Sarcobatus vermiculatus [Hook.] Torr.), [Fig. 86].
Alkali-heath (Frankenia grandifolia campestris Gray), [Fig. 87].