UNIVERSITY OF CALIFORNIA PUBLICATIONS.

University of California— College of Agriculture,

AGRICULTURAL EXPERIMENT STATION.

LANDS OF THE COLORADO DELTA IN THE SALTON BASIN.

FIELD AND LABORATORY WORK

By FRANK J. SNOW.

DISCUSSION

By E. W. HILGARB and G. W. SHAW.

BULLETIN No. 140.

(Berkeley, Febniary, 1902.)

SACRAMENTO: a. j. johnston, : : : : : superintendent state printing.

1902.

BENJAMIN IDE WHEELER, Ph.D., LL.D., President of the University.

EXPERIMENT STATION STAFF.

E. W. HILGARD, Ph.D., LL.D., Director and Chemist.

E. J. WICKSON, M.A., Horticulturist.

W. A. SETCHELL, Ph.D., Botanist.

R. H. LOUGHRIDGE. Ph.D., Agricultural, Geologist and Physicist. (Alkali Investigations.)

C. W. WOODWORTH, M.S., Entomologist.

M. E. JAFFA, M.S., Assistant Chemist. (Foods, Soils, Fertilizers.)

G. W. SHAW, M.A., Ph.D.. Assistant Chemist. (Soils, Sugars.)

GEORGE E. COLBY, M.S., Assistant Chemist. (Fruits, Waters, Insecticides.)

J. BURTT DAVY, Assistant Botanist.

LEROY ANDERSON, M.S. A., Dairy Husbandry.

A. R. WARD, B.S.A., D.V.M., Veterinarian, Bacteriologist.

E. H. TWIGHT, B.SC, Diplome E. A.M., Instructor in Viticulture.

W. T. CLARKE, Assistant Entomologist.

C. H. SHINN, B. A., Inspector of Stations.

C. A. COLMORE, B.S., Clerk to the Director.

EMIL KELLNER, Foreman of Central Station Grounds.

JOHN TUOHY, Patron,

}■ Tulare Substation, Tulare. JULIUS FORRER, Foreman,

R. C. RUST, Patron,

y Foothill Substation, Jackson. JOHN H. BARBER, Foreman, )

S. D. MERK, Patron, )

}• Coast Range Substation, Paso Robles. J. W. NEAL, Foreman, \

S. N. ANDROUS, Patron, ) ( Pomona.

J- Southern California Substation, ■< J. W. MILLS, Foreman, ) { Ontario.

V. C. RICHARDS, Patron, )

v Forestry Station, Chico. T. L. BOHLENDER, ?n charge, )

ROY JONES, Patron, )

> Forestry Station, Santa Monica. WM. SHUTT, Foreman, \

Bulletins and reports of this Station will be sent free to any citizen of the State , upon application.

'

NOTICE.

Attention is called to the fact that certain errors occur in Table I, page 7, of Bulletin 140 of this Station. The errors have been cor- rected in the following reprint, and you are requested to insert it in the proper place in the said bulletin.

— /

TABLE I. Preliminary Results of Alkali Leachings.

Locality.

1.

2.

3 4 5 6

7 8. 9 10 11 12 13 16 17. 18 19 20-

Percent ages.

Sul- Carbon- Chlo- rates, ates. rids.

Total, > Sulfates.

Pounds per Acre in 4 Feet.

I Carbon -

.196 .068 .129 .162 .072 .294 .042 .631 .179 .207 .173 .172 .141 .142 .080 .056 .129 .152

.013 .010 .012 .007 .010 .008 .009 .013 .009 .010 .010 .014 .011 .012 .007 .009 .009 .009

.094 .043 .082 .045 .019 .496 .002 .424 .162 .027 .056 .044 .164 .137 .035 .001 .005 .154

.303 .121 .223 .214 .101 I .798 I .053 | 1.068 I .350 I .244 ! .239 .230 .316 .291 .122 .066 . 143 .315

ates.

Chlorids.

Average in 4 fpet.. Minimum in 4 feet Maximum in 4 feet

31,360

10,880 20,640 25,920 11.520 47,040 6,720 100,960 28,640 33,120 27,680 27,520 22,560 22,720 12,800 8,960 20,640 24,320

484,000

26,888

6,720

100,960

2,080 1,600 1,920 1 , 1 20 1,600 1,280 1,440 2,080 1,440 1,600 1,600 2,240 1,760 1,920 1,120 1,440 1,440 1,440

15,040 6,880

13,120 7,200 3,040

79,360 320

67,840

25,920 4,320 8,960 7,040

26,240

21,920

5,600

160

800

24,640

29,120 1,612 1,120 2,240

318,400

17,688

160

79,360

Total.

48,480 19,360 35,680 34,240 16,160

127,680 8,480

170,880 56,000 39,040 38,240 36,800 50,560 46,560 19,520 10,560 22,880 50,400

831,520 46,195

8,480 170,880

It will be observed that this preliminary examination indicates the average total alkali in the first four feet of soil to be about ly per cent. or 46,000 pounds per acre; about three-eighths of which is common salt and about three-fifths glauber salt. Further, the enormous variation from 8480 to 170,880 pounds of soluble salts per acre — from a soil which will not injure citrus fruits to one that would be repugnant to all but the hardiest of alkali plants — shows that the land is quite "spotted," some localities being too highly charged with alkali to admit of any successful agricultural operations, while others do not exceed in amount the salts found in some of the better agricultural regions of the State. This condition suggested forcibly the need of a detailed local examination of the region.

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TABLE OF CONTENTS.

GENERAL DATA REGARDING THE SALTON BASIN.. 5

Successive efforts at investigation 6

Preliminary results of alkali leachings ; table 7

Exploration by Mr. F. J. Snow 7

Variability of alkali in soils 8

THE SOILS OF THE BASIN 8

Classification 8

Physical Characteristics _• 8

Physical tests and analyses of the soils; table 9-10

Percolation of water; diagram 11

Practical deductions 12

Capillary power ; diagram 13

Chemical Composition '. 15

Analyses of Colorado alluvial soils 15

Intrinsic fertility of these soils 16

The Soluble Salts in the Soils 17

Importance of the alkali factor in soils of arid regions 17

The nature of alkali _. 18

Alkali Salts in the Salton Basin 19

Sections of New River and Salton River banks 19

Determination of alkali in these river sections; tables 20

Summary of salts in the river sections; tables and diagrams 21-23

General conclusions from these sections __ 24

Soils of the General Surface of the Basin _ 25

Physiographic features 25

New River, alkali in soils contiguous to; table 27

Salton River, alkali in soils contiguous to; table. ._ 31

Soluble Salts in Yuma Alfalfa Lands; table 33

General Summary 33

IRRIGATION WATER 34

Analyses of Colorado River and Lake Waters; table 35

Manner of Irrigating Alkali Lands; diagram 36

Drainage 39

VEGETATIVE CHARACTERISTICS OF THE SALTON BASIN 40

General Considerations 40

Annotated List of Plants Collected: by J. Burtt Davy 41

CLIMATE OF THE SALTON BASIN 45

CROPS FOR THE SALTON BASIN LANDS 45

Possible Crops ._ 46

Toleration of Alkali Salts by Certain Crops; table 49

January Crop' Reports Received from Actual Settlers 50

M A^

OF THE

SOUTHERN PART

SALTON BASIN

SAN DIEGO COUNTY

CALIFORNIA

LANDS OF SALTON BASIN, SOUTHERN CALIFORNIA.

The Salton Basin, in the southeastern portion of the Colorado Desert, within the State of California, is a depression about 290 feet below sea level at its lowest point, where thick saline deposits have given rise to important enterprises in mining common salt. While the northern portion of this basin is largely covered with drifting sand, surrounding many tracts that, with irrigation, produce (as at Indio) abundant and early crops, the southern portion, here being considered, is to a consider- able extent covered with alluvial deposits originally derived from the Colorado River; as is clearly indicated by their nature, as well as by the fact that at times of exceptional high water (such as occurred in 1890) the river overflows into the basin through two channels, named respectively the Salton and New rivers. In the year mentioned, the overflow was so copious as to flood the salt deposits, and for nearly a year there was a lake where doubtless originally the waters of the Gulf of California received the entire flow of the Colorado. The alluvial deposits of the river finally cut off the upper end of the Gulf, so that now a large area of alluvial country, or delta, extends between the Salton Basin and the present head of the Gulf. The part of this delta which slopes toward the north into the Salton Basin forms the subject of the present discussion. The subjoined map, reduced from sheets furnished by the "Imperial Land Company," will serve to elucidate the general features of the region, a portion of which has been surveyed in sufficient detail to give the contour lines indicating the slope, which, as will be noted, is considerable enough to render both irrigation and drainage easy; in general, toward a depression designated as Mesquit Lake, which can also serve as a back-water reservoir from Salton River and the main canal. To the eye, however, most of the country appears as a level plain, except where the channels of the streams form breaks. Its natural vegetation is very scanty; mesquit is found scattered over the plains, with locally some poplars on the lower ground; also low shrubby and herbaceous, partly saline, growth. On the higher ground vegeta- tion is generally very sparse, sometimes entirely absent over consider- able tracts; locally there are areas in which certain plants are massed.

As to the thickness of these delta deposits, the only evidence as yet available is from a boring at Imperial made to determine the feasibility of obtaining artesian water in this region. This boring was carried to the depth of 685 (?) feet, without penetrating anything different from

the various materials found at or near the surface, and without finding water. It is thus apparent that the Gulf was originally of very consider- able depth. The level of the Salton salt deposit at the works is stated by Gannett to be 262 feet below sea level.

Successive Efforts at Investigation. — The attention of the Station Director was first called to the agricultural possibilities of this southern portion of the Colorado Desert in 1893, by a request on the part of several gentlemen who proposed to take out water from the Colorado River near Yuma, for the purpose of irrigating this region; and also proposed to fit out an expedition, properly equipped, in order that he might explore the country in question personally. Financial difficulties intervening prevented the carrying-out of the plan at that time; but a few samples of water from the lakes, and of soils superficially taken, proved that the latter were very similar to that of the immediate bottom of the Colorado River, which previous analyses had already shown to be of extraordinary intrinsic fertility.*

A similar effort was made in 1896-7 by other parties, who also sup- plied to the Station some soil and water samples for examination. These but corroborated the previous conclusions, with the added sugges- tion that a considerable proportion of alkali salts was present in soils as well as in waters; so that a thorough examination of the region in this respect was manifestly called for.

It was not until 1900, however, that the present organization, the " Imperial Land and Water Company," took active steps toward the construction of an irrigation canal, and renewed the proposition that the land should be explored under the supervision of this Station, in order to determine definitely its adaptation to general or special agriculture and horticulture. The first step was the taking of soil samples over a considerable portion of the district by an employe of the company, in substantial accordance with printed directions furnished. These samples, unfortunately, could not be very accurately located, in the absence of a regular land survey; but they furnished a fair general idea of the character of the lands, and further emphasized the necessity of a more definite and detailed examination, in order to determine what portions of the territory under the canal might or might not be con- sidered suitable for general farming purposes.

To indicate the general idea obtained from the analysis of these twenty preliminary samples, the results have been calculated so as to show the soluble salts (alkali) to the depth of four feet, taking the average alkali content found in the soils to the depth to which each sample had been taken, and assuming that this represents approximately the saline con- dition for each foot.

*See report of California Experiment Station for 1882.

/ —

TABLE I. Preliminary Results of Alkali Leachings.

Percentages.

Locality.

1...

2...

S...

4...

5...

6...

7...

8...

9... 10.. . 11... 12... 13... 16... 17... 18... 19... 20...

Sul- fates.

.196 .068 .129 .162 .072 .294 .042 .631 .179 .207 .173 .172 .141 .142 .080 .056 .129 .152

Carbon- Chlor- ates, ids.

Pounds Per Acre in 4 Feet.

Total, j Sulfates.

Carbon ates.

Chlorids. Total

.013 .010 .012 .007 .010 .008 .009 .013 .009 .010 .010 .014 .011 .012 .007 .009 .009 .009

.094 .043 .082 .045 .019 .496 .002 .424 .162 .027 .056 .044 .164 .137 .035 .001 .005 .154

.303 .121 .223 .214 .101 .798 .053 L.068 .350 .244 .239 .230 .316 .291 .122 .066 .193 .315

Average in 4 feet... Mininium in 4 feet Maximum in 4 feet

31,360 10,880 20,640 25,920 11,520 47,040

6,720 96,960 28,640 33,120 27,680 27,520 18,560 22,720 12,800

8,960 20,640 24,320

575,320

28,766

6,720

96,960

2,080 1,600 1,920 1,120 1,600 1,280 1,440 2,080 1,440 1,600 1,600 2,240 1,760 1,920 1,120 1,440 1,440 1,440

29,120 1,456 1,120 2,240

15,040 6,880

13,120 7,200 3,040

79,360 160

16,960

25,920 4,320 8,960 7,040

26,240

21,920

5,600

160

800

6,160

248,880

12,444

160

79,360

48,480 19,360 35,680 34,240 16,160

127,680 8,280

170,880 56,000 39,040 38,240 40,800 50,560 46,560 19,520 10,560 30,880 50,400

853,320 42,666

8,280 170,880

It will be observed that this preliminary examination indicates the average total alkali in the first four feet of soil to be about one per cent, or 40,000 pounds per acre; about two-sevenths of which is common salt and about two-thirds glauber salt. Further, the enormous variation from 8,280 to 170,880 pounds of soluble salts per acre — from a soil which will not injure citrus fruits to one that would be repugnant to all but the hardiest of alkali plants — shows that the land is quite " spotted," some localities being too highly charged with alkali to admit of any successful agricultural operations, while others do not exceed in amount the salts found in some of the better agricultural regions of the State. This condition suggested forcibly the need of a detailed local examination of the region.

Exploration by Mr. F. J. Snow. — The Director being unable to visit the region personally, Mr. F. J. Snow, at the time assistant in the laboratory of agricultural chemistry, was deputed to undertake the work of exploration, and the field work was carried out by him with the effective assistance and at the expense of the company, during the three weeks of Christmas vacation, 1900-1901. The examination of the numerous samples it was found necessary to collect occupied over four months of his time during 1901; and the resignation of Mr. Snow from the staff of the Station at the beginning of the session of 1901-2 una- voidably delayed the report of results until the vacancy thus created could be acceptably filled. Almost the entire laboratory work had

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An examination of this table shows that the silt soil contains about 60 per cent of silt of medium to coarse grade, which imparts the distinc- tive character to the soil. It also carries from 10 to 15 per cent of very fine silt, which in some respects might act

., , t mi Diagram I. Rate of percola-

similarly to clay in respect to capillary power. tion in 12 hours

The soil characterized as clay carries about 30 clay goil silt soilB

per cent of clay proper, and over 60 per cent of 3 12

very fine silt; making over 90 per cent of ex- tremely fine matter, which, when compacted (as much of it is), makes a material almost *— ins"

impervious to water. The truth of this latter statement is well illustrated by the results obtained in the percolation experiments (diagram I); and it is obvious that a material of this character can not be considered suitable for irrigation culture, or, in fact, blns' for any of the usual crops under any practically pos- sible treatment. It is too, " fat" even for potter's clay, for which its high plasticity would otherwise render it suitable.

As is natural, intermixtures of these two extreme materials in various proportions are frequently found, often in shaly masses resembling the hard clay, but 12 ins. softening readily in water and quite capable of suc- cessful cultivation if freed from excess of alkali. The "hand test," by wetting with water and working between the palms of the hands, and the observation of their percolative power, will generally serve to distinguish these shaly clay-loams from the intractable hard clay of the New River banks.

18 ins.

Percolation of Water. — In irrigated regions the rapidity with which soils can be wetted is a question of prime importance to the farmer; and with a view of ascertaining the rate at which water will be taken by each of the two types of soils here discussed, the following experiments were undertaken. Experi- ments No. 1 and No. 2 were conducted with the silt soil, and No. 3 with the clay soil. No. 2 was designed as a check upon No. 1, and was conducted at a dif- ferent time; but all essential conditions were made as similar as possible. In each experiment the same constant depth of water was maintained over the soil- column by means of a Marriotte apparatus. In experiment No. 1 the tube used was one and one 29 ins half inches in diameter and thirty-eight inches in length, and contained 1,700 grams of soil. In experiment No. 2 (he

- 12 —

diameter of the tube was two inches, and the length thirty-two inches, the weight of the soil being 1,400 grams. In each case the soil was well settled in the tube. Experiment No. 1 was begun at 6:20 a. m., April 15th, and ended at 11:25 p. m. of the same day. Experiment No. 2 was begun at 5:20 a. m., May 2d, and ended at 9:14 p. m. of the same day. The rate of wetting is graphically presented in the accompanying exhibits (diagram I), in which the depth reached in twelve hours is shown.

Practical Deductions. — In soils as strong in alkali as these samples, the rate of wetting becomes even a more important factor for considera- tion than in non-alkali regions. Wherever the upper layers of the soil are highly charged with the salts, the first thing needful to be done — aside from thorough underdrainage — is that of heavy irrigation by flooding, in order to wash the excess of alkali from the upper layers to the lower, and thus reduce the amount in the upper four to six feet of soil below the limit of endurance for the various crops. (For a discussion of the "Tolerance of Alkali by Certain Cultures," the reader is referred to Bulletin No. 133 of this Station.) If an excessive amount of water has to be used in order to accomplish this washing-down, or if the water has to be kept upon the ground an undue length of time, there is the constant attendant danger of "swamping" the soil, and thus putting it out of good physical condition; and again, in a soil in which the lime carbonate runs as high as seems to be the case in these soils, there is the further danger of the development of black alkali, thus adding to the already serious condition of many of the sampled areas. If, however, the soil be of such a nature as to preclude the possibility of wetting it thoroughly to a depth of five or six feet within a reasonable length of time under irrigating condi- tions, then if it be placed under cultivation, there may be expected a considerable increase of alkali near the surface during the first three or four years.

Comparing these two soils it was found that under these experiments the silt soil became wet to the depth of three feet within 18 hours, while in the case of the clay soil it required 165 days for the water to reach the same depth; a rate entirely prohibitive of successfully handling this soil under its highly saline conditions. Further, the experiment indi- cates that this clay soil is so slow in taking moisture from above that in a period of ten days it would only become wet to a depth of seven inches, a rate too slow for agricultural operations.

In the silt soil, the conditions for successful treatment under irrigation are much more favorable. Carrying, as it does, a heavy amount of alkali within the first three feet, the same method of heavy flooding and subsequent deep-furrow irrigation would have to be resorted to; and a

13 —

study of the data shows that if the water will carry a considerable por- tion of the salts to a depth of four or five feet within a reasonable time, the conditions may be considered as favorable as in many other well- cultivated portions of the arid regions. The experiments show that this may be accomplished within a period of 18 to 36 hours, a time perfectly compatible with agricultural practice. The particular thing here shown should be distinctly borne in mind; namely, that it is as important for intending settlers to be as careful to avoid the compact clay soils as those carrying excessive amounts of alkali.

In connection with the silt soil, in view of its looseness of texture, its often highly saline condition, and the heavy percentage of lime carbon- ate which it carries, attention should be directed to the great liability to seepage from the higher ground, especially where near the main canal, to the lower lands. Instances of this are so common in irrigated regions that forewarned should be forearmed. Sooner or later there will arise the necessity of drainage canals to keep the seepage water from " swamp- ing" the lower land. With this underflow of water there is a greater or less accumulation of alkali salts in the lower areas, which, taken in con- nection with the high natural lime content of the soils, is almost sure to result in the formation of considerable black alkali; a condition which may already be seen in a few isolated localties where there has been a periodic overflow from New River. One such is indicated on the map by the number 25, and covers about 200 acres.

In dealing with the grades of soil intermediate between the two ex- tremes here tested, it will be advisable to determine first of all the rate at which water will penetrate them to the depth of not less than four, preferably five or six, feet. This will at once indicate whether the alkali salts can be successfully leached out of the land on a practical scale. The test can be made either by digging a pit, alongside of which water is put on the land; or else by following the water down by means of the soil auger.

Capillary Power. — The height to which, and the rapidity with which water will rise by capillary movement (wick action) in soils from underground or sub-irrigation water, and the ease of its general trans- mission in all directions, is a matter of vital importance in agricultural operations, particularly in arid regions. While both the height and the rapidity of transmission are to a large degree dependent upon the physical nature of the soils, yet it is reasonably certain that there are certain chemical factors involved as well. Inasmuch as this capillary power is dependent upon the size of the spaces between the particles constituting the soil, varying inversely as this space, capillary ascent is less in sandy than in clay soils. In the former the rise is more rapid, since there is less frictional resistance to the motion of the water; but

14 -

there is, also, much less surface tension, and while the rise is rapid the water may not ascend more than a few inches.

As between silts and clays, such as we have to deal with in this dis- cussion, the conditions are quite different and merit some attention,

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particularly as these silt soils are so prevalent in the arid regions. The soils used in this experiment were from the same lot as those used in the percolation experiments and in the complete chemical and mechan- ical analyses described above. The soils were tapped into the tubes, which were then placed upon a perforated support in a water reservoir.

— 15 —

The results are shown graphically by means of both curves and vertical columns. In the case of the curves, the verticals represent equal heights in inches; the horizontals show the length of time in days. In the columns, to facilitate comparison, the points reached in each at the end of the several periods of time are connected by lines.

The particular point to attract attention in comparing these two soils is the great difference in the rapidity of the rise of water. In the case of the silt soil, in seven minutes it had ascended 2 inches, in eighteen minutes 4 inches, in one hour 7 inches, in one hour and forty-three minutes 10 inches; while it took the clay eleven hours and seventeen minutes to draw the water to a like height, or approximately ten times as long. This rate, however, diminishes somewhat more rapidly in the silt as the water column ascends, than it does in the clay. This rapid rise of water in soils of a somewhat similar character was noticed some years ago, and commented upon in the annual report of this Station for 1894. In the case of the alluvial soil from Gila River, near Yuma, the water rose 9^ inches in one hour; at the end of twelve hours it had reached a height of 24 inches, and at the end of the first day it had reached the height of 27^ inches; while the silt soil here under con- sideration reached the height of 30 inches in a like time. The clay soil of the region must be looked upon, then, as very slow in its capillary action when compared with the lighter alluvial silt, the ratio for the first few hours being about 1:10.

CHEMICAL COMPOSITION OF THE SOILS.

In a previous report* of this Station, analyses of three samples of soil from this region are given, and in the discussion of the results it was stated: "It will be noted, as a common factor of these three soils, that they are highly calcareous; they show the presence of the carbonate of lime by effervescence with acids. The Colorado River soil is very rich in potash; the Gila soil much less so, yet very adequately sup- plied; the amount of soda found does not indicate much alkali con- tamination. The Colorado soil has a good, but not high, supply of phosphoric acid; the Gila soils both show an unusually high percentage of that ingredient. The Colorado soil has a good supply of humus; the Gila soil is notably deficient therein for a bottom soil."

A complete chemical analysis of each of the types here under con- sideration was made by Mr. Snow, and the subjoined results obtained. The analysis of other soils from the same region, the discussion of which appears above, is included for the sake of comparison.

* Report of California Experiment Station, 1890, p. 50.

16

TABLE III. Analyses of Colorado Alluvial Soils.

Clay Soil.

Silt Soil.

No. 2324. 1 No 2R25.

Colorado

River,

California,

Bottom

Soil.

No. 506.

Gila River.

Arizona,

Bottom

Soil.

No. 1195.

Gila River, Arizona, Bottom Subsoil.

No. 1197.

Coarse materials >0.5E Fine earth

Analysis of Fine Earth.

Insoluble matter

Soluble silica

Potash (K,0)

Soda(Na.O)

Lime (CaO)._

Magnesia (MgO)._

Br. ox. of manganese (Mn304).

Peroxid of iron (Fe203 )

Alumina (A1203 )

Phosphoric acid (P205)

Sulfuric acid ( S03 )

Carbonic acid(C02)

Water and organic matter

Total

Humus

" Ash

" Nitrogen, per cent in humus..

" Nitrogen, per cent in soil

Available phosphoric acid (citric acid

method)

Hygroscopic moisture (absorbed at

15° C.)

Water-holding power

100.00

38.65

15.79

.76

.34

4.35

1.24

.10

6.15

10.52

.23

.49

5.30

15.84

99.76

.38

1.01

18.42

.07

.012

5.75 74.39

100.00

62.67

10.93

.74

.29

3.75

1.68

.01

3.71

4.26

.22

.36

2.32

8.93

100.00

58.57

5.33

1.18

.16

8.67 2.97

100.00

57.90

13.49

.66

.25

6.26

.66

.03 14 ,38 13 ,15 ,82 ,34

99.87

.65

.69

10.92

.07

.01

2.98 46.26

100.87

.75 1.15

.08 5.57 7.48 .23 .03 2.63 4.98

100.00

64.83

11.85

.67

.39

4.33

1.97

.03

6.27

4.27

.17

.05

3.56

1.14

100.22

.38 .43

99.83

9.26

48.40

4.91

3.48 42.30

Intrinsic Fertility of these Soils. — In a general review of these soils, one is impressed at first by the general similarity in composition, bearing out the statements made several years ago and quoted above, viz: that the intrinsic fertility of the soils of this region is high. The lime content of all three is high; and the fact that this lime is present largelv in the form of a carbonate, as indicated by the high per cent of carbonic dioxid, also indicates a high general availability of the other critical elements. In the case of the clay it will be noted that there is a much larger portion of soluble matter than in the silt, which is further shQwn by its higher alkali content, discussed later in this bulletin. In this latter respect both the silt and soil No. 506 have the advantage of the clay. This fact is also borne out by the higher per cent of both soda and sulfuric acid present in the clay when compared with the other soils. There is about two thirds as much soluble silica in the silt as in the clay. As to potash, all three soils are very rich, there being nearly four times as much as the average for soils of humid regions. In this respect the soils must be considered as permanently fertile. On the side of phosphoric acid there is little difference in the two types, both having an excellent supply, exceeding that of soil No. 506 quite materiallv: still, the latter could not be considered deficient. The

— 17 —

humus content is good — better in the silt than in the clay — especially as the nitrogen content of the humus is high. The water-holding power is greater by 30 per cent in the case of the clay than in the silt, which might be expected on account of the difference in the nature of the two soils. All three of these soils must thus be ranked as exceptionally good in their supplies of plant food.

THE SOLUBLE SALTS IN THE SOIL.

Importance of the Alkali Factor in Arid Regions. — In the selection ot lands in arid regions it is highly essential that more than the physical nature and general fertility of the soils be considered. There are factors entering into the soil problems of such regions which are entirely foreign to those of humid climates, and which, in many cases, are far more complicated. A soil may possess all the elements, both physical and chemical, of intrinsic fertility, and still be entirely unsuited to agricultural operations under irrigated conditions; points which, in a humid region, might be considered very favorable to a soil may, under irrigation, if the alkali condition of the undersoil be not accurately known, cause the ruin of the land. Being unaware of these essential differences, settlers from the humid region are not infrequently led to select land which is, or may become, entirely unsuited to any kind of crop-growing. It is important, then, that the truth should be placed before them in these matters, not only that they may avoid financial loss, but also that the evil results sure to follow such unwise selections may not cast reflections upon the State. On the other hand, it is not at all uncommon for people temporarily residing in arid regions to make broad and sweeping condemnations of lands which experience and a thorough understanding of arid conditions will not bear out.

Alkali lands, when at all adapted to agriculture, are intrinsically of the very richest character; and may, as a rule, be considered as exceptionally fertile upon the mineral side when compared with the humid-region soils. In order to realize these advantages, however, care is needed in handling such lands, and ignorance of the true condition may cause very serious financial loss, both to the individual and to the State. A notable case is that of the Fresno plateau region — the divide between the San Joaquin and Kings rivers — where there were no signs of alkali when the region was settled and for some time thereafter. Gradually small spots of alkali appeared in the older settlements, enlarging from year to year as the point of tolerance was passed for the several crops, finally causing the death of vines and trees to such an extent as to attract serious attention. It has only required a thorough understanding of the conditions to point out an application of the rational treatment of drainage, combined with the use of gypsum, when needed, as a remedy for a trouble that threatened to overrun the country. 2— Bul. 140

— 18 —

The alkali factor should always, therefore, receive careful attention as to both surface and undersoil conditions. Three points demand consideration in this connection, viz:

1. The soluble salt content of the soil itself;

2. The salt content of the available irrigation water;

3. The condition of the surface and sub-drainage in connection with the nature of the soil.

The Nature of Alkali. — The nature and kinds of alkali have been repeatedly treated of in the several publications of this Station, but it is deemed best to again state here that, "broadly speaking, it may be said that, the world over, alkali salts usually consist of three chief ingredients, namely, common salt, glauber salt, (sulfate of soda), and salsoda or car- bonate of soda. The latter causes what is popularly known as " black alkali," from the black spots or puddles seen on the surface of lands tainted with it, owing to the dissolution of the soil humus; while the other salts, often together with epsom salt, constitute " white alkali," which is known to be very much milder in its effect on plants than the black. In most cases all three are present, and all may be considered as practically valueless or noxious to plant growth. With them, how- ever, there are almost always associated, in varying amounts, sulfate of potash, phosphate of soda, and nitrate of soda, representing the three elements — potassium, phosphorus, and nitrogen — upon the presence of which in the soil, in available form, the welfare of our crops so essen- tially depends, and which we aim to supply in fertilizers. The potash salt is usually present to the extent of from 5 to 20 per cent of the total salts; phosphate, from a fraction to as much as 4 per cent; the nitrate, from a fraction to as much as 20 per cent. In black alkali the nitrate is usually low, the phosphate high; in the white, the reverse is true."*

With regard to the relative injuriousness of the component salts it may be said that the glauber salt, unless present in excessive amounts, is comparatively innocuous and need not be considered a serious barrier to agricultural operations when conducted in a rational manner. The carbonate of soda, constituting the active ingredient in the so-called "black alkali," exerts a corrosive action on the root crown of the plant, and in many cases, especially in heavy soils, tends to destroy their tilth. But by the use of gypsum, it can readily be converted into the relatively innocuous sulfate. Experience on our substation tracts, as well as else- where, shows that any considerable amount of sodium chlorid (common salt) is fully as much to be feared as the more corrosive carbonate, since it can not be neutralized or changed within the soil, but must be bodily removed by drainage.

* Bulletin No. 128, California Experiment Station, p. 13.

— 19 —

ALKALI SALTS IN THE SALTON BASIN.

In considering only the amounts of alkali salts in the soils of this region, we find the outlook not altogether encouraging. While there is some land not too strongly impregnated to produce even now, without any special precautions, good crops of cereals, especially barley, also alfalfa, and some of the hardier orchard and small fruits, there is a very large proportion of the lands so strongly charged that, without due care, crops could be secured only for two or three years, and in some, none at all. As to quality, however, it is notable that there is in the great majority of cases a great predominance of the relatively innocuous sulfates — glauber salt, epsom salt, and throughout, a certain proportion of potash sulfate also, ranging in the determinations thus far made from two to over ten per cent of the total salts. Carbonate of soda is quite subordinate, because of the presence of gypsum throughout the materials. Common salt is rather abundant near the surface, but only in small supply below the first three feet, until a depth of twenty feet is reached, as is shown in the sections given below. Nitrates appear to be present throughout, to an extent varying from 1,000 to 1,800 pounds per acre (.025 to .044 per cent) in four feet depth; increasing from the surface downward, contrary to the usual rule. The alkali is, therefore, generally speaking, of the mildest " white " type, and it is not surprising that, as the crop reports given below show, seed germinates and a luxuriant growth of weeds is found even where the alkali salts are bodily blooming out along the ditches. It would thus seem that, on the whole, the hard clay is a more serious obstacle to the utilization of these extremely rich lands than are the alkali salts, so far at least as the lighter and more pervious soil qualities are concerned.

Sections of New River and Salton River Banks. — Below will be found tables and diagrams showing the results of analyses of samples taken in vertical sections from the banks of both the Salton and New rivers. These samples were taken, as indicated in the tables, to the depth of 22 feet 9 inches, and 22 feet respectively, the banks in each case having been dug away for 20 feet horizontally in order to get truly representa- tive samples, avoiding the effects of concentration of salts by evapo- ration. These sections are of especial importance as indicating the general disposition of the soluble salts in the substrata of the valley; they consequently elucidate best the chances of getting rid of alkali by drainage, or by leaching downward on the land itself. The tables show the data obtained from the two stream banks, the nature of the materials being given alongside of the same.

20 —

TABLE IV. Section from New River Bank: 22 Feet, Locality No. 33.

Percentages.

CO p t— • P CD 00	o g o* o p p CD w
.916	.008
1.321	.010
1.164	.008
.736	.016
.556	.016
.572	.012
.593	.007
.286	.007
.371	.013
.376	.010
.631	.012
.661	.013
.522	.013
.584	.009
.572	.014
.258	.007
.232	.008
.195	.008
.257	.007
1.188	.010
1.130	.008
1.244	.012
1.143	.005
1.162	.007

o

p-

Pi

o

Physical Characteristics of Each Thickness.

Pounds per Acre.
X	O	' O	H
d	P	£T	o
	>-i
p	o	o	p
CD 00	p p <rH CD oo

.092 .265

.096

.060 .037 .032 .036 .249 .018 .014

.076

.016

.029 .011 .078 .015 .025 .021 .003 .006 .068 .026 .036 .063

1.016 1.596

1.268

.812 .609 .616 .636 .542 .402 .400

.719

.690

.564

.604

.280

.265

.224

.267

1.204

1.206

1.282

1.184

1.232

8 in. Surface compacted clay; I crumbles easily. t

12 in. Compacted clay ; crura- » bles easily. )

12 in. Very tough clay ; will not j 1 break nor crumble. j

..4 in. Very hard ; breaks in cakes.. .12 in. Compacted, but not as hard. .12 in. Very hard; breaks in cakes. .12 in. Very hard; breaks in cakes. .12 in. In large chunks ; very hard . .12 in. Notashard; more silt; mixed. . 6 in. Notashard; more silt; mixed. j 12 in. Hard compact clay; caked ) in chunks. f

12 in. Hard compact clay; caked j

1

.. 12 in. ..12 in. .. 6 in. .. 12 in. ._ 12 in. .12 in. .. 12 in. . 12 in. . 12 in. .12 in. .12 in. . 12 in.

in chunks. Compact; some silt Compact; more silt Compact; more silt Loose silt and sand Loose silt and sand Loose silt and sand Loose silt and sand

Very compact

24,427

52,840

46,560

9,813 22,240 22,880 23,720 11,440 14,840

7,520

25,240

26,440

20,880 23,360 10,240 10,320 9,280 7,800 10,280 47,520 45,200 49,760 45,720 46,480

213 | 2,653 400 i 10,600

320

214

640 480 280 280 520 200

480

520

520 360 280 280 320 320 280 400 320 480 200 280

3,840

800 1,480 1,280 1,440 9,960 720 280

3,040

640

1,160

440

1,560

600

1,000

840

120

240

2,720

1,040

1,440

2,540

27,293 63,840

50,720

10,827 24,360 24,640 25,440 21,680 16,000 8,000

28,760

27,600

22,560 24,160 12,080 11,200 10,600 8,960 10,680 48,160 48,240 51,280 47,360 49,280

Sand and water at 22 feet.

TABLE V. Section from Salton River Bank: 22 Feet 9 Inches, Locality No. 34.

195	.007	.080	.282
603	.012	.329	.944
356	.008	.038	.402
233	.008	.025	.266
095	.007	.006	.107
181	.008	.013	.202
129	.011	.003	.143
121	.009	.009	.143
164	.010	.012	.186
225	.008	.003	.236
.260	.005	.007	.272 i
.467	.007	.009	.483
.331	.009	.028	.368
.417	.009	.026	.452
207	.008	.011	.226
315	.012	.015	.342
.998	.008	.012	1.018
.372	.008	.006	.386
.193	.014	.074	.281
292	.020	.044	.356
.132	.008	.008	.148
092	.010	.089	.191
416	.008	.168	.592
686	.009	.285	.980
771	.010	.739	1.520

12 in. Silty; some clay some-)

what compacted. j

12 in. Similar to above, but |

more compact. <j

6 in. Like first foot

12 in. Like first foot

12 in. Very loose, silty soil;

little sand.

12 in. Very loose, silty soil; a)

little sand. \

j 6 in. Silt ; some clay ; slightly j

} compact. j

12 in. Silt; compact breaks to)

silt soil. j

12 in. Silt; some clay

j 12 in. Silt; some clay some-)

( what compacted. j

j 3 in. Silt; some clay some-j

( what compacted. j

j 12 in. Silt ; some clay some

( what compacted.

.. 12 in. Silt; very loose

.. 6 in. Clay; compact

..12 in. Silt; some clay

.. 12 in. Silt; some clay

.. 12 in. Silt; lumps crumble easily.

.. 12 in. Silt; very fine

.12 in. Silt; very fine

..12 in. Clay; compact

.. 12 in. Clay; compact.

.12 in. Clay; compact

7,800	280	3,200
24,120	480	13,160
7,120	160	760
9,320	320	1,000
3,800	270	240
7,240	320	520
5,160	440	120
2,420	180	180
6,560	400	480
9,000	320	120
10,400	200	280
4,670	70	90 !
13,240	360	1,120
16,680	360	1,040
8,280	320	440
12,600	480	600
19,960	160	240
14,880	320	240
7,720	560	2,960.
11,680	800	1,760
5,380	320	320 j
3,680	400	3,560 :
16,640	320	6,720 i
27,440	360	11,400 \|
30,840	400	29,560

11,280

37,760

8,040

10,640

4,280

8,080

5,720

2,860

7,440

9,440

10,880

4,830

14,720

18,080

9,040

13,680

20,360

15,440

11,240

14,240

5,290

7,640

23,680

39,200

60,800

— 21

TABLE VI. Showing Summary of Soluble Salts in the River Sections.

(Pounds per acre.)

	Salton River Silt.	New River Clay.
	Sul- fates.	Carbon- ates.	Chlor- ids.	Total.	Sul- fates.	Carbon- ates.	Chlor- ids.	Total.
	For Total Depth : 22 ft. 9 in.	For Total Depth : 22 ft.
Total Average per foot. .. Min. in any foot... Max. in any foot...	281,864 12,812 3,680 30,840	7,348 334 200 800	73,590 3,345 120 29,560	362,802 16,491 4,280 60,800	663,806 30,173 7,800 50,780	8,580 390 200 640	52,402 2,291 120 10,600	722,788 32,854 8,960 63,840
	For First 4 Feet.	For First 4 Feet.
Total	50,044 12,511 6,560 24,120	1,376 344 295 480	18,240 4,560 620 13,160	69,660 17,415 7,460 : 37,160 !	155,888 38,972 22,240 50,780	1,788 447 346 640	13,372 5,343 1,480 8,347	177,040 44,260 24,360 59,133
Average per foot .. . . Min. in any foot... Max. in any foot. ._
	For the Next 6 Feet.	For the Next 4 Feet.
Total	42,678 7,113 5,000 10,400	1,992 332 295 400	1,818 303 120 480	46,560 7,760 5,720 10,880	109,320 18,225 11,440 23,720	2,340 390 280 520	20,070 3,345 720 9,960	131,760
Average per foot .. Min. in any foot... Max. in any foot...	21,960 16,000 25,440

In comparing the column of total salts, it is at once apparent that the New River materials are much more heavily charged with salts than are those on Salton River. Looking closer at the nature of these materials, we find, moreover, that while the Salton profile shows mostly silts and sands, which make an easily worked loam soil, the material of the New River bank is prevalently a very close-grained, fine clay, which is practically impervious to water, as shown in the percolation experiment previously recorded. (See p. 11.) In the Salton profile we also find occasional layers of this clay; and inspection shows that in nearly all cases this clay is more heavily charged with salts than is the silt and sand. Thus this clay, which wets with great difficulty and when wet becomes extremely tough and plastic, is a very unwelcome soil ingredient, as it is incapable of tillage and will be penetrated only by such hardy roots as those of the mesquit and greasewood, and possibly by those of the saltbushes. It is quite unlikely that other useful trees will be able to force their roots through this uncanny material, and settlers will quite early find from experience what is quite evident from these experiments : that these clay lands are ill adapted to agricultural operations, even where a few feet of silt forms the surface.

There are, as stated, many grades of transition between this pure, tough clay and the silt, which is eminently suitable as a soil material, and when mixed with a moderate amount of the clay forms excellent

22

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"• i o^ it it.	M^
>. I T	/	&K
" i	A-
s i i	_*. s / ^ /
	— - h u. / s /	_. -4
	i i1 y ^ 1TW* rfe+YTl \	^1 «s •*

02

O

w

u

■u >

P5 o

0)

o

a o

P. oS

o

— 24 — 4

loams or clayey soils. Such soils sometimes constitute the surface soil itself, more frequently form layers of the substrata within reach of the roots of culture plants, and of course should be well distinguished from the practically impenetrable clay described above, as well as from the loose silts proper.

The distribution of the salts is better shown to the eye in the graphic form, as given on diagrams III and IV. Here we see at a glance that there are two high maxima of total salts, viz: near the top and at the base of the profile, with a minor one midway between in the case of New River; while in that of the Sal ton River there is at 15 feet as heavy a maximum as near the surface, with minor increases above and below. Another and very important point of difference is that while on New River there is no notable increase of the common salt near the base of the profile, on the Salton the sodium chlorid seems to increase very materially, almost equaling the sulfate, which elsewhere is throughout the sections in considerable excess. The sulfate (glauber salt) being the least noxious by far of the three salts usually contained in "alkali," this is a strong redeeming feature of the conditions in the region. It must be noted, however, that in both profiles the common salt is in quite heavy supply near the surface, constituting one fourth of one per cent of the soil in the New River banks, and one third of one per cent in that of Salton River.

Comparing the total content of salts in the two profiles, we see at once that it is by far the heavier in the New River profile, where the average content per acre of the entire section, as shown in the table on pages 20-21, is 32,854 pounds; while the same on Salton River is only 16,491 pounds, or just one half as much.

The New River section is mainly clay; that on the Salton is mainly silt and sand, but with an occasional sheet of clay. It will be noted that wherever such a sheet occurs, the alkali content is heavier; in full agreement with the same fact at the New River section. The clay, then, must be regarded not only as an obstacle to tillage and root penetration, but also as a prolific source of alkali salts. Wherever it is at, or within less than three feet of the surface, the land should be considered as unsuit- able for cultivation at this time.

The conclusion as to alkali content is again corroborated by the shal- lower sections from which soil samples were collected by Mr. Snowr; thus, in localities Nos. 3, 6, 14, 15, 16, 17 (see tables below). There is also a decided increase wherever the silt is compacted by the presence of considerable clay. In a few cases only, mostly near the surface, where one would naturally expect an accumulation, is the loose silt strongly impregnated with salts.

Again, in comparing these two river-bank sections in respect to the

— 25 —

upper four feet of soil, it is found that the same fact, i. e. that the clay is the stronger in alkali, still holds good, for the average is about two and a half times higher in the case of the New River clay than in the Salton silt, and the minimum in the latter is 4,280, against twice as much in the former. What is true of the average of the total salts is also true of the average of each ingredient; and it is still further interesting to note that in general the same fact holds for the next four feet, which includes a depth as great as need be considered in any agricultural practice.

Disregarding the hard clay as being unsuitable for agricultural opera- tions, and looking more closely at the silt, it will be seen that in the six feet underlying the upper four the average of the total salts is less than one half as high as in the latter; thus indicating that the proper treat- ment of these lands will be that of heavy flooding for reducing the amount of salts in the upper layers of the soil, followed by deep-furrow irrigation until leaching by underdrainage shall become practically feasible.

SOILS OF THE GENERAL SURFACE OF THE BASIN.

Besides the profiles on the banks of the two rivers, soil samples were taken in the open country, with a view to making them representative of the various districts, so far as time permitted. In so doing, the several layers of materials encountered in boring were taken separately, gen- erally to the depth of six feet when conditions permitted; and a speci- men of each layer was preserved for analysis. The general aspect and ulay" of the land were recorded, and the vegetation, if any, noted and specimens thereof preserved for subsequent identification, as possible indicators of the strength and character of the alkali salts.

PHYSIOGRAPHIC FEATURES. (By Me. Snow.)

" Localities Nos. 1, 5, 6, 7, 17, 18, 19, and 23 represent that portion of the region lying west of New River; Nos. 1, 5, 6, and 23 representing that portion north of the proposed townsite. This latter area is a level country many miles in extent. The soil is generally a hard, compact clay, and in spots bears a heavy growth of greasewood; in the im- mediate locality of No. 23 there is a rank growth of pig-weed. Three miles from this point a 27-foot well has been dug, in which the clay extends to a depth of 12 feet, the remainder of the depth being sand. Localities Nos. 17, 18, and 19 were south of the proposed townsite, near the Mexican border, and represent an area of very level country extending parallel to New River far across the line into Mexico. The soil of this area, also, is a heavy, compact clay. The vegetation along

— 26 —

the river and around the lakes is very rank and abundant, but on the agricultural land represented by these samples it is scarce and scattered. Over more or less of this area there are numerous hummocks, on which are found dead mesquit and greasewood bushes.

" Localities Nos. 3, 4, 8, 12, 13, 14, 15, 16, 26, and 27 were between the two rivers. Localities Nos. 3, 4, and 8 represent land lying north of the proposed townsite, over which a hard, compact clay soil predomi- nates, and all of which is without vegetation. Near the point where sample 8 was obtained was a water-hole containing very saline water. A dense growth of trees, particularly willows and poplars, occurs in the river-bed at this point. Samples 14, 15, 16, and 26 were taken around the proposed townsite, and represent a large body of level land lying near the center of the agricultural district. The land has but little vegetation and is composed of hard, compact, impervious clay soil. Sample 27 represents a large area of so-called l blown-out' land lying near Blue Lake, and a larger area of similar land lying on the west bank of the Salton River and joining the Mexican line on the south. Near sample 27 is a small body of black-alkali land.

" The locality represented by 9, 11, and 20 is that known as the ' East Side Tract,' a large area of land extending from the east bank of the Salton River to the sand hills on the east, and including all the irri- gable lands to the Mexican line. These lands for some distance back from the river are much broken by large arroyos which lead into the Salton River. The soil is generally of a silty character, more or less mixed with clay in the northern part, and becoming more silty and sandy as the Mexican line is approached. Over this area the vegetation is scarce in the northern part, but near the Mexican line there is a rank growth of pig- weed, saltbush, greasewood, arrow-wood,* and sand verbena (Abronia) . All the plants are to be found in this part of the country in abundance, and reach an enormous size.

" The country represented by localities Nos. 21 and 22 lies in Mexico, and consists of a loose, pervious, silty soil, which is overflowed annually by the waters of the Colorado River. The vegetation in these localities is very rank and abundant."

*By this name are indicated two different plants; see list, p. 42.

— 27 —

TABLE VII. Alkali Salts in Soils Contiguous to New River, San Diego County.

Locality No. 1— T. 14 S., R. 14 E., Sec. 6.

o

•B

B

cr ►J. o

pr

S3

Percentages.

GO

B o

C P hi

o- o

B

O BJ O (-■• Oi on

o

Physical Characteristics.

Potinds per Acre.

c

a

>-1

cr o

B P

C

t— • o

o

12 24

36

48 60

72

12	.218
12	.090
12	.026
12	.092
12	.136
12	.155

.005 .013 .019 .014 .007 .015

.001 .004 .003

.001 .004

.224 .107 .046 .106 .144 .174

... Silt; loose ... . Silt ; very fine .

ditto

Silt; some sand ditto

Total for vertical section

8,720 3,600 1,040 3,680 5,440 6,200

28,680

200 520 760 560 280 600

2,920

40

160

40

40 160

440

8,960 4,280 1,840 4,240 5,760 6,960

32,040

Locality No. 3— T. 12 S., R. 13 E., Sec. 36.

10	10	.767	.010	.157	.934
22	12	.995	.009	.392	1.396
36	14	.172	.012	.010	.194

Total for vertical section

Clav; slightlv compact

..... ditto

ditto

25,567

39,800

8,026

333

360 560

5,233 1 15,680 467

73,393

1,253

21,380

31,133

55,840 9,053

96,026

Locality No. 4— T. 13 S., R. 14 E., Sec. 5.

12	12	.755	.013	.318	1.086
24	12	.179	.012	.019	.210
36	12	.081	.012	.005	.098
48	12	.057	.012	.009	.078
60	12	.063	.016	.009	.088

Total for vertical section

Silt; very fine ..

ditto

30,200	520	12,720
7,160	480	760
3,240	480	200
2,280	480	360
2,520	640	360
45,400	2,600	14,400

43,440 8,400 3,920 3,120 3,520

62,400

Locality No. 5— T. 12 S., R. 13 E., Sec. 33.

12	12	.254	.020	.014	.288
16	4	.079	.010	.033	.122
30	14	.105	.007	.014	.126
42	12	.081	.012	.014	.107
54	12	.095	.014	.009	.118
72	18	.120	.006	.014	.140

Total for vertical section

Silt; very loose

ditto

_ ditto .

ditto ._

...ditto

Clay; compact

10,160	800	560
1,053	133	440
4,900	327	653
3,240	480	560
3,800	560	360
7,200	360	840
30,353	2,660	3,413

11,520 1,626 5,880 4,280 4,720 8,400

36,426

Locality No. 6— T. 13 S., R. 14 E., Sec. 18.

12	12	.070	.046	trace	.116
18	6	.244	.008	trace	.253
32	14	.140	.008	.140	.288
44	12	.063	.009	.002	.074
60	16	.058	.019	.002	.079
72	12	.062	.010	trace	.072

Total for vertical section

116 -Silty clay ; compact.

.Silty clay; loose. .. .Clay; very compact.

Silt ; very loose

_. . ditto

ditto

2,800	1,840
4,880	160
6,534	373
2,520	360
3,100	993
2,840	40
22,674	3,766

trace

6,533

80

107

trace

4,640 5,040 13,440 2,960 4,200 2,880

6.720 ' 33,160

— 28

P a

cd

OO

o

P

CO

p

o

p-

CD

TABLE VII— Continued.

Locality No. 7— T. 13 8., R. 13 E., Sec. 11.

Percentages.

P

o p

c o

B P

P* »— <

o

i-s »-" CL t»

o

Physical Characteristics.

Pounds per Acre.

CO

P

o p

o* o P P

CD

03

a p; o

H o

6	.862	.019	.276	1.157
6	.317	.008	.239	.564
4	.335	.010	.009	.354
2	.427	.009	.117	.553
12	.151	.001	.047	.205
12	.165	.011	.014	.190
6	.111	.012	.023	.146
3	.185	.009	.028	.222
2	.121	.010	.019	.150
3	.279	.014	.033	.326
16	.061	.013	.014	.088

6 12 16 18 30 42 48 51 53 56 72

Total for vertical section

...Silty clay; loose...

Clay; compact

Silt; loose

ditto..

ditto

.Silty clay ; compact. ...Silty clay; loose...

Clay; compact

.. .Silty clay; loose...

17,240 6,340 4,466 2,846 6,040 6,600 2,220 1,850 807 2,790 3,253

380

160

134

60

280

440

240

90

67

140

693

5,520 4,780 120 780 1,880 560 460 280 126 330 747

54,452 2,684

15,583

23,140 11,280 4,720 3,686 8,200 7,600 2,920 2,220 1,000 3,260 4,693

72,719

				Locality No. 8-	-T. 13 S.,	R. 14 E.	, Sec. 6.
12 24	12 12	.097 .903	.014 .002	.017 .173	.128 1.078		....Silt. ....Silt.	3,880 36,120	560 80	680 6,920	5,120 43,120
Total for vertical section		40,000	640	7,600	48,240

Locality No. 14— T. 15 S., R. 13 E., Sec. 13.

4	4	.731	.007	.075	.813
16 30 40	12 12 10	.642 .423 .301	.012 .013 .013	.211 .154 .150	.865 .590 .464
56	16	.335	.012	.323	.670
68 72	12 6	.388 .592	.009 .009	.103 .080	.500 .681

Total for vertical section

j Clay; somewhat j | compact. j

ditto

.... ditto

Clay; compact. ..

Clay ; somewhat compact.

ditto

9,747	93
25,680 16,920 10,033	480 520 433
17,867	640
15,520 11,840	360 180
107,607	2,706

1,000

8,440 6,160 5,000

17,226

4,120 1,600

43,546

10,840

34,600 23,600 15,466

35,733

20,000 13,620

153,859

Locality No. 15— T. 15 S., R. 14 E., Sec. 16.

12	12	.249	.005	1.928	2.182
24	12	.621	.003	1.076	1.700
36	12	.476	.025	.497	.998
48	12	.396	.021	.181	.598
60	12	.399	.019	.170	.588
72	12	.245	.015	.070	.330

Clay; lumpy..

.ditto

ditto

Clav; compact.

ditto

Total for vertical section

9,960 24,840 19,040 15,840 15,960

9,800

200 120 1,000 840 760 600

93,440 i 3,520

77,120

43,040

19,880

7,240

6,800

2,800

156,880

87,280 68,000 39,920 23,920 23,520 13,200

255,840

Locality No. 16— T. 15 8., R. 14 E., Sec. 18. (Imperial.)

12	12	.478	.007	.013	.498
72	12	.243	.019	.006	.268
72	72	.562	.012	.018	.592

.498 j Clay; lumpy.

Clay; compact

Total for vertical section

19,120 i 9,720

280 j 19,920 760 240

134,880 2,880

134,880 j 2,880

39,420 10,720

4,320 ; 142,080

4,320 142,080

— 29

TABLE VII— Continued.

Locality No. 17— T. 16 S., R. 13 E., Sec. 33.

o a ■a tr1	& a d CO CO P go	Percentages.	Physical Characteristics.	Pounds per Acre.
a a CD CO	GC 1— • M» P <rt- <T> GO i	Q P C o 0 P r* CD GO	o o co ■ !	H3 o erf- P i— i	CO S3 1— ■ p ST CO	o p >-t a1 o 3 P r*- CD 09	■I CO i i	H o 9
9 24	9 15	.241 .572	.009 .009	.014 .051	.264 .632	Clay; lumpy. ... Clay; compact	7,230 28,600	270 450	420 2,550	7,920 31,600
Total for vfirtinal section		35,830	720	2,970	39,520

Locality No. 18— T. 17 S., R. 13 E., Sec. 20.

12	12	.302	.013	.014	.329
18	6	.575	.015	.426	1.016
30	12	.400	.020	.136	.556
34	4	.188	.017	.033	.238
46	12	.180	.021	.014	.215
58	12	.158	.012	.019	.189
72	14	.078	.027	.009	.114

Clay; lumpy..

.Clay; very compact.

Clay; lumpy..

...Silt; very loose.

ditto

ditto.

ditto

Total for vertical section

12,080	520	560
11,500	300	8,520
16,000	800	5,440
2,507	240	1,320
7,200	840	560
6,320	480	760
3,640	1,260	420
59,147	4,440	17,580

13,160 20,320 22,240 3,167 8,600 7,570 5,320

80,377

Locality No. 19— T. 17 S., R. 14 E., Sec. 21.

12	12	.480	.008	trace	.488
24	12	.333	.008	.094	.435
36	12	.065	.020	.005	.090
42	6	.117	.013	trace	.130
54	12	.013	.025	trace	.038
66	12	.065	.009	trace	.074
72	6	.051	.009	trace	.060

. Silty clay; lumpy .

Clay; lumpy

ditto

Silty clay ; compact

Sandy; loose

ditto

._ ditto

Total for vertical section.

19,200	320	trace
13,320	320	3,760
2,600	800	200
2,340	260	trace
520	1,000	trace
2,600	360	trace
1,020	180	trace
41,600	3,240	3,960

19,520 17,400 3,600 2,600 1.520 2,960 1,200

48,800

Locality No. 21 — Mexico.

8	8	.231	.011	trace	.242
14	6	.736	.019	.037	.792
26	12	.316	.014	.004	.334
38	12	.118	.011	.002	.131
46	8	.076	.019	.001	.096
55	9	.159	.013	trace	.172
60	5	.143	.025	.061	.229
72	12	.151	.020	.004	.175

Clay

Clay; compact ..

ditto

..Silty clay; lumpy

ditto..

ditto

Total for vertical section

6,159	i 294
14,720	380
12,640	560
4,720	440
2,280	253
4,770	390
2,393	417
6,240	80
54,432	2,814

trace	6,453
740	15,840
160	13,360
80	5,240
27	2,560
trace	5,160
1,016	3,816
160	7,000

2,183 59,429

Locality No. 23— T. 13 S., R. 14 E., Sec. 15.

12	12	.508	.003	.445	.956
24	12	.652	.003	.215	.870
36	12	.580	.010	.080	.670
48	12	.424	.005	.066	.495
60	12	.333	.012	.183	.528
72	12	.617	.009	.131	.757

.. Silty clay ; lumpy .

Clay; compact...

ditto..

ditto

Total for vertical section

20,320	120	17,800
26,080	120	8,600
23,200	400	3,200
16,960	200	2,640
13,320	480	7,320
24,680	360	5,240
124,560	1,680	44,800

38,240 34,800 26,800 19,800 21,120 30,280

171,040

— 30 —

TABLE VII— Continued.

Locality No. 26— T. 15 S., R. 13 E., Sec. 25.

B o

B"

CO

H B* a

3

B o

B-

CO

Percentages.

02

O

P

a" o B P

a

00

O BJ

O

>-t

a.

co

H o

Physical Characteristics.

Pounds per Acre.

03

B

O P >-»

c o B P «-t- (t> co

O

B* o

co

4

16 28 40 52 64

4 12 12 12 12 12

.138 .362 .200 .163 .165 .129

.007 .004 .001 .016 .004 .006

.009 .098 .065 .033 .023 .019

.154 .464 .266 .212 .192 .154

...Clay; compact

..ditto

...ditto

ditto

1,840 14,480 8,000 6,520 6,600 5,160

93 160

40 640 160 240

Total for vertical section

42,600

120

3,920 I

2,600

1,320

920

760

1,333 J 9,640

2,053 18,560 10,640

8,480 7,680 6,160

53,573

Locality No. 27— T. 15 S., R. 13 E., Sec. 34.

12	12	.044	.012	trace	.056
30	18	.032	.020	trace	.052
36	6	.001	.024	trace	.025
42	6	.032	.017	.005	.054
54	12	.027	.011	trace	.038
66	12	.092	.012	.014	.118
72	6	.195	.016	.037	.248

Total for vertical section

.. Silt; loose ..

ditto

.Clay ; lumpy. .. Silt; loose ..

ditto

ditto.....

1,760 1,920 20 640 1,080 3,680 3,900

13,000

480	trace
1,200	trace
480	trace
340	100
440	trace
480	560
320	740
3,740	1,400

2,240 3,120 500 1,080 1,520 4,720 4,960

18,140

TABLE VIII. Summary Table, showing Soluble Salts to Depth of 4 Feet.

Region.

New River

Locality.

Pounds per Acre.

Sulfates. I Carbonates.

Chlorids.

Total.

1

4

5

6

7 ..

14

15

16

18

19

21

23

26

27

Average . Minimum Maximum

17,040 42,880 21,253 17,509 45,752 71,313 69,680 89,920 30,340 37,720 43,579 96,560 35,240 4,880

44,547

4,880

96,560

2,040 1,960 3,020 2,977 1,694 2,036 2,160 1,920 2,780 1,200 2,024 840 1,039 2,720

2,028

840

3,020

240

14,040

2,393

6,640

14,100

29,213

148,280

2,847

16,527

3,960

1.007

32|240

8,573

100

20,011 100

148,280

19,320

58,880

25,666

27,026

61,546

102,372

219,120

94,787

49,627

42,880

46,610

119,640

44.852

7,700

66,586

7,700

219,120

— 31 —

TABLE IX. Alkali Salts in Soils Contiguous to Salton River. Locality No. 2— T. 13 S., R. 14 E., Sec. 4.

o

a>

tf

**•

s a V a

DO

& o

*t

tt en

CO

a a

&

CD

Percentages.

Physical Characteristics.

Pounds per Acre.

Sulfates

o

H &

o

3 ?o

0>

oo

o

Dj CO

i i

Total

Sulfates

V o

a

ro

o

(3* O

Si

CO

o

P

48

.072

.008

.014

.094

Clay; compact

11,520

1,280

2,240

15,040

Locality No. 9-T. 13 8., R. 15 E., Sec. 2.

6	6	.343	.014	.075	.432
18	12	.623	.016	.117	.756
30	12	.444	.017	.145	.606
36	6	.333	.013	.098	.444
48	12	.120	.013	.047	.180
60	12	.258	.014	.220	.492
72	12	.115	.013	.103	.231

. ..Clay; lumpy

Clay ; very compact . ditto

ditto

.. Silt; some sand ...

Clay ; very compact .

ditto

Total for vertical section

6,860	280	1,500
24,920	640	4,680
17,760	680	5,800
6,660	260	1,960
4,800	520	1,880
10,320	580	8,800
4,600	520	4,120
75,920	3,480	28,740

8,640 30,240 24,040

8,880

7,200 19,680

9,240

108,120

Locality No. 10— T. 13 S., R. 16 E., Sec. 6.

11	11	.118	.006	.008	.132
16	5	.101	.008	.002	.111
30	14	.106	.008	.004	.118 \|
36	6	.486	.008	.026	.520 '

Sand ; fine, very loose ... Sand and gravel 118 ! Coarse sand

Total for vertical section

4,327	220	293
1,683	134	33
4,046	373	187
9,720	160	520
20,676	887	1,033

4,840

1,850

5,506

10,400

22,596

Locality No. 11— T. 13 S., R. 15 E., Sec. 36.

14 23 35 41 53 57

14 9

12 6

12 4

.527 .282 .189 .238 .192 .087

017	.150 S
012	.028 i
014	.079
011	.009
011	.009
014	.009

.694 j Clay; shaly

.322 I Silt ; very loose....

.282 ] ditto

.258 i Clay; compact

.212 ditto.

.110 Silt; loose

Total for vertical section

24,593	793	7,000
8,460	360	840
7,560	560	3,160
4,760	220	180
4,680	440	360
1,160	186	120
54,213	2,559	11,660

Locality No. 20— T. 16 S., R. 16 E., Sec. 22.

32,386 9,660

11,280 5,160 8,480 1,466

58,432

12 30 42 54

72

12 18 12 12

18

.161 .151

.022 .017

.010 .012

.010 .008

.033 .005

trace .005

.204 .168

.032 .030

Clay; snaly ditto

Sandy . ditto .

6,440 9,060

880 1,020

400 720

400

480

1,320 300

trace 300

8,160 10,080

1,280

1,800

♦Sample spoiled by becoming wet.

Locality No. 22—8 miles south from Sec. 8, R. 17 E., Mexican line.

12	12	.224	.012	.001	.237
24	12	.341	.012	.033	.386
36	12	.376	.012	.014	.302
48	12	.275	.014	.047	.336

Silt; very fine

ditto

Total for vertical section

8,960 13,640 15,040 11,000

48,640

480 480 480 560

1,900

40

1,320

560

1,880

3,800

9,480 15,440 12,080 13,440

50,440

— 32 —

TABLE X. Summary Table, showing Soluble Salts to the Depth of 4 feet in localities . near Salton River.
Locality.	Pounds per Acre.
Sulfates.	Carbonates.	Chlorids.	Total.
2	11,520 61,000 48,103 48,640	1,280 2,380 2,190 1,900	2,240 15,820 11,390 3,800	15,040
9.	79,200 61,596 50,440
11 .
22

Average. -. - Minimum ... Maximum	42,314 11,520 61,000	1,938 1,280 2,380	8,312 2,240 15,820	52,564 15,040 79,200

Even a cursory glance at the preceding tables shows that the distri- bution of the silty and clay lands is very much "spotted"; for while there^s a general predominance of clay on the west, contiguous to New River, especially in the westward bend of that channel, in range 13, there are also two silt localities (Nos. 5 and 7) in the same range, together with localities 1, 4, 6, 8, and 19 in range 14. Elsewhere we find in ranges 14 and 15, localities 2 and 9 with compact clay soils, although generally silts are predominant on the Salton. Only detailed mapping can therefore segregate the several areas; but each one can test the soil character easily by boring or digging, or preferably by the irrigation test, i. e., noting how rapidly the water will penetrate to the depth of from three to six feet, according to the crops it is intended to plant. In the absence of ditches, water sufficient for the purpose can be hauled to the spot.

That the two deep vertical sections do not represent the worst of the land is shown in the more shallow sections from near New River, where eight out of fourteen of the more shallow sections exceed the deep sec- tion from New River bank in the total alkali present. In the case of the shallow sections from near Salton River, however, the condition does not appear to be as bad, for but one out of four exceeds the river-bank section in the total alkali present in the first four feet.

In looking closely at the lesser sections, as well as at those taken from the river banks, there will be seen a general tendency for a break to occur in the total alkali content after the second foot, which generally seems to carry a larger amount of salts than the top foot. This break will serve largely as a saving clause for the lands, in many cases ren- dering it possible to reduce the alkali in the upper layers of the soil below the maximum of tolerance for crops. Particularly will this be true in growing alfalfa, which has been found to resist a surprising amount of alkali when it is once well rooted. In this same region excel-

— 33 —

lent fields have been grown where the soil carried as high as 110,000 pounds of alkali to the depth of six feet, and 79,760 pounds to the depth of four feet. The figures showing the alkali content of two of the alfalfa fields near Yuma are herewith presented.

Sample 28 was taken two miles south of Yuma in Mr. C. C. Dyer's alfalfa field.

Sample 31 was taken from the alfalfa field adjoining Mr. Smith's dairy, one and one half miles south of Yuma. The soil was moist to a depth of 5 feet.

TABLE XI. Showing Soluble Salts in Yuma Alfalfa Lands.

		b CO V a o & <t> oo	l-= B* >-" o <t> GO co y	Percentages.	Pounds per Acre.
Physical Characteristics.	co ►-ta P e-t- <t> CO	o P l-S O SO GO	o o GO	o w ?o <-►	CO fa a> CO	o a" o P CO GO	o o so	H O p CO p in
oo* f ..Silt; very loose.. <^ j ..ditto £ I ditto ^ ditto	12 24 36 48	12 12 12 12	.402 .683 .456 .328	.010 .013 .008 .008	.012 .038 .016 .014	.424 .734 .480 .350	16,080 27,320 18,240 13,120	400 520 320 320	480 1,520 640 560	16,960 29,360 19,200 14,000
a i CO I	.467	.009	.020	.499	74,760	1,560	3,200	79,520
CO 0) a eS	' Silt; loose ditto _ ditto .. __ ditto ._ Clay; lumpy _. Silty clay ; lumpy	12 24 36 48 60 72	12 12 12 12 12 12	.356 .829 .416 .248 .342 .371	.008 .010 .008 .009 .009 .008	.018 .031 .044 .017 .027 .007	• .382 .870 .468 .274 .378 .386	14,240 33,160 16,640 9,920 13,680 14,840	320 400 320 360 360 320	720 1,240 1,760 680 1,080 280	15,280 34,800 18,720 10,960 15,120 15,440
	.427	.009	.024	.459	102,480	2,080	5,760	110,320

It is safe to say that much of the land near Salton River will produce excellent crops of this forage plant if it can once be started. The young plants of this crop are quite sensitive to alkali, and in most instances it would be necessary to reduce the salts in the upper layer of the soil by heavy and deep irrigation in order to secure a stand. It took four years to secure good stands in the above fields.

That it is possible to do this in most cases on the Salton River silts can be seen by referring not only to the sections from the river bankj but also to the lesser sections. In a previous publication from this Station (Bulletin No. 133), Dr. Loughridge has shown that when young this plant will stand in the neighborhood of 12,000 pounds of salts. When the distribution of the alkali in the silt soil is considered in con- nection with the rapidity of percolation, as shown by the experiments previously discussed, the condition for crop-growing on these soils seems quite favorable. There is, however, a distinct disadvantage in the case

3— Bul. 140

— 34 —

of the silt soil for crops which require open culture, namely the high capillary power; which will tend to hring up the alkali rapidly when exposed to surface evaporation after irrigation. To successfully culti- vate these lands and not experience a very serious u rise of alkali," it is very imperative that they be at all times kept in good tilth by frequent and deep cultivation. If this be not done there is almost sure to follow a very serious alkali condition in the upper layers of the soil.

Looking again at the tables and profiles, we find throughout that the carbonates are insignificant, and, except so far as there is a likelihood that under heavy irrigation they may be formed in the future, can be left out of consideration at present. As to the chlorids, the land near New River seems to carry the larger amount; which might be expected from what has been said heretofore. It shows the enormous range of 100 to 148,280 pounds per acre to a depth of four feet; and when the generally high chlorid content of these clays is considered, together with their other unfavorable properties, it is apparent what a hopeless task it will be to attempt to handle them successfully. The people who have been unfortunate enough to settle upon these dense, hard clay soils should change to some more auspicious location, the sooner the better.

THE IRRIGATION WATER,

A consideration of the soluble salt content of the available irriga- tion water is of nearly as great importance as a like consideration of the soils themselves; for when water highly impregnated with alkali is used for irrigation purposes, all the alkali in that portion of the water which evaporates from the surface will be left in the land, and if the water be very bad the land may soon become so highly charged with alkali from this cause alone that it will not grow profitable crops. This fact is the more important in case the lands to be irrigated are them- selves as heavily loaded with alkali as those under consideration; for the salts left after the evaporation of the water become an added evil with which to contend, and may prove "the straw that breaks the camel's back."

It is not easy to state absolute figures as to what constitutes an excess of salts in water to be used for irrigation purposes, for not only must the nature of the saline content of the water be considered, but also that of the land to be irrigated. The far more variable factor, the quantity and frequency of irrigation required, also demands attention.

Speaking along this line in a previous publication, the Director of the Station has said: " Broadly speaking, the extreme limit of mineral content usually assigned for potable waters, viz: 40 grains per gallon, also applies to irrigation waters. Yet it sometimes happens that all or

— 35 —

most of the solid content is gypsum and epsom salt; when only a large excess of the latter would constitute a bar to irrigation use. When, on the contrary, a large portion of the solids consists of carbonate of soda, or common salt, even a smaller proportion of salts than 40 grains might preclude its regular use, depending upon the nature of the soil to be irrigated. For in a clay loam, or heavy adobe, not only do the salts accumulate nearer the surface, but the sub-drainage being slow and imperfect (unless the land is underdrained), it becomes difficult, or impossible, to wash out the saline accumulations from time to time, as is readily feasible in sandy soils."

Subjoined is a table showing analyses of the water of the Colorado River which is used for irrigation purposes in the region. In the same table are shown analyses of water from two of the lakes, and of a well in the region, all the analyses having been made by Mr. Snow.

TABLE XII. Water Analyses.

Colorado River " near Head Gates."

Turbid.

Q

~p

o<» 3d

. CD

O CO Op

Clear.

O

Op

3d . CD

*-■ P O oo

2 m.

Blue Lake.

d

CD

•-»

Q p

o

P

o o

©

Well at

Cameron

Lake.

O >-t

p

m

d

CD

>-«

O p

t—'

o

p

o o

o

Cameron Lake.

Q	*d
<-i	P
P	i-«
»-<•	cr*
3	CO
co	M*
d	S3
CD	h—
>1	o
Q P	o o o

o
P

Total residue by evapora- tion

Soluble in water after evaporation _..

Insoluble in water after evaporation

Organic matter and chemically combined water

The soluble part consists

of-

Sodium and Potassium sulfates (glauber salt, etc.) .. .

Sodium chlorid (com- mon salt)

Sodium carbonate (sal soda) ...

79.73 33.57

38.55

7.59

13.65 5.75 6.60

1.30

The insoluble part consists of—

Calcium and magnesium carbonates

Calcium sulfate (gyp- sum) _

Silica

Residue upon slight igni- tion

19.35 6.75

7.42

{►21.32

i

J 17.23

3.32 1.16 1.27

3.65 2.95

Browns.

51.11

33.59 9.93

7.59

21.20 6.82 5.57

9.35

.58

8.75 5.75 1.70

1.30

3.64

1.16

.95

1.60<|

.10

Does not blacken.

26.57 4.55

16.94 6.42

3.21

2.33 4.09

5.55

trace

.87

Blackens

2.90 1.10

.55

.40 .70

.95

.15

43.69 23.95 15.07

4.67

7.38 4.10

2.58

.80

21.22 3.64

2.73 trace

1

13.73

j sm. 1.34

.46

trace

2.35 ".23 Browns.

104.96

78.56

16.65

9.75

40.45 23.87 14.24

sm

16.36 .29

Blacken^

17.97 13.45

2.85

1.67

6.93 4.08 2.44

2.80 .05

36

In connection with the above table we give two analyses of the Colorado River water from the Eleventh Annual Report of the Arizona Experiment Station. Each analysis represents water from samples taken over periods of a week :

Silt by volume

Silt by weight

Total soluble solids .

Sodium chlorid

Permanent hardness ; stated as calcium sulfate

Grains per U. S. Gallon.

Jan. 22-28. Apr. 25-May 1. Low water. Medium flow.

.392% .115%

33.24 10.26

8.24

These analyses show the composition of the water to be quite variable at different periods of the same season and in different seasons. It will be noted that the maximum concentration shown is over 58 grains of soluble salts per gallon when the water is at a low stage, and that these fall to about 30 grains per gallon during the period of medium flow. In the Arizona report previously referred to it is farther stated that "the total soluble solids were observed to average as low as 25 parts per 100,- 000 (14.5 grains per gallon) for months at a time." It is during this time, so far as possible, that the water would be mainly used for irri- gation purposes, thus indicating the water to be of fair quality for use upon the silt soils. The quantity of soluble salts is influenced by the stage of the water and by the seepage from irrigation districts; the latter materially influences the character of the salts present. That this is so may be seen by comparing the proportion of sodium chlorid present at the several times, for at one period (in 1900) this ingredient reaches a maximum of one third of the total soluble salts, and in another consti- tutes only about one fifth. The carbonates appear to form about one sixth of the total. While this water could be used with impunity upon the silts, it would but increase the extremely undesirable saline condi- tions of the clay soils of the region.

Manner of Irrigating Alkali Lands. — The manner of using water upon these lands, in order that the salts may not be brought to the surface and thus increase the saline condition, especially of the upper foot, is of great importance in handling these strongly saline lands. The general principle has been indicated at several points in this publication, viz: that of leaching down the salts in the soil itself, thus reducing the amount of alkali in the upper foot, and taking it out of reach of the tender rootlets of the young plants especially. The water under the^e conditions should not be kept on the tract for a less period than twenty- four hours, and for a thorough leaching-down a considerably longer time should be given. The behavior of the soil when irrigated should

— 37 —

be the first thing tried in order to test the possibilities of successful cul- tivation; taking into consideration the known fact that the rapidity of absorption ("taking water") gradually increases under cultural condi- tions, largely because of the loosening of the soil by the crop roots, as well as by tillage.

" It is not practicable, as many suppose, to wash the salts off the sur- face by a rush of water, even when visibly accumulated there, as they instantly soak into the ground at the first touch. Nor is there any sensible relief from allowing the water to stand on the land and then drawing it off; in this case also the salts soak down ahead of the water, and the water standing on the surface remains almost unchanged. In very pervious soils, and in the case of white alkali, the washing-out can often be accomplished without special provision for underdrainage, by leaving the water on the land sufficiently long. But the laying of regular underdrains greatly accelerates the work, and renders success certain."*

After the salts have been washed down so as to relieve the surface soil of any excess injurious to the germination of seeds or the life of young seedlings, irrigation by flooding must, except in the case of crops that fully shade the ground, be practiced only at long intervals, if at all. To prevent the "rise of the alkali" that is sure to follow continued surface flooding, the water should thereafter be applied in deep furrows, from which the water will chiefly soak downward and sideways only, and preferably not rise to the surface at all. Evapo- ration from the soil surface is the cause of the accumulation of the salts at and near that surface; to prevent it it is necessary to avoid wetting the latter, and this is best brought about by deep-furrow irrigation, which, at the same time, allows of a considerable saving of water, while tending to deepen the root-system and so to bring it out of reach of the destructive heat and drought of summer.

Diagram V illustrates the manner in which irrigation water can be used so as to prevent its reaching the surface to any such extent as to cause a serious amount of evaporation. The solid lines represent the manner of penetration of water from furrows 8 inches deep, as actually observed at the Southern California substation near Pomona (see Bul- letin No. 138, page 38) in two different soils, of which the heavier (to the left) resembles most nearly in texture the silt and loam soils of the Salton Basin. The dotted lines show the effects that would have been produced had the furrow been made deeper to the extent of 7 inches; in which case the water would have reached the surface only at the edges of the furrows, so that when these are subsequently closed by plowing there would be practically no surface evaporation, and no after-cultiva- tion would be required to prevent crusting-over.

* Bulletin No. 128, California Experiment Station.

38 —

It is evident that with the proper implements for the purpose, such deep-furrow irrigation, to prevent the re-ascent of alkali near the surface, could be made a ready means of utilizing a large proportion of the alkali lands here in question without any difficulty, and with a

Clay Loam. Sandy Loam.

Zit. 1ft. 0

lit. lit

I'.hSt

7Z HOURS AFTER IRRIGATION Diagram V. Percolation experiments. Spread of water from deep furrows in heavy and light soils.

material saving of water and cost of surface cultivation, in addition to the advantages secured in the deeper penetration of the roots into materials which, as the sections of the river banks show, are but very slightly tainted with alkali salts.

Of course, this method is best applicable to crops grown in rows, as

— 39 —

orchards and vineyards, sorghum, corn, etc. For broadcast crops it can only be used in rather pervious soils, which can be irrigated by lateral seepage when laid off in "lands" of a width proportionate to the rapidity of water-penetration. In the Mussel Slough district such lands are made about 50 feet wide; but as the soils here in question are not nearly as open, they would have to be made narrower. By following this method carefully and intelligently, most of the lands of the silty character can probably be successfully cultivated to crops not too sensitive to alkali, provided they are not underlaid at too shallow a depth by the impervious clay; as is frequently the case between the two rivers. The clay will of course arrest the alkali-laden irrigation water in its downward course, and thus from a depth of a few feet it will be constantly reascending toward the surface. Such land will be hard to cultivate successfully without actual underdrainage, except to the hardiest crops, such as sorghum, barley, and shallow-rooted plants generally. Alfalfa can hardly be a success on land having the clay within less than five feet; for fifteen or twenty feet are ordinary depths of penetration for its roots. When the clay layer is not of great thickness and is underlaid by silty materials, success in tree-planting may be attained by blasting with giant powder; as is commonly done with hardpan of other kinds, when a good soil material is known to lie beneath. In the case of alfalfa, modiola, and other plants which eventually cover and shade the ground very fully, the evaporation through the* roots and leaves will largely prevent the rise of the alkali, even when flooding is practiced.

It is clear that, in this region at least, no farmer can afford to be ignorant of the undersoil conditions upon his land; and if heavy irriga- tion is practiced, he should make absolutely sure by personal observation that the soil is actually being wetted to the depth of five or six feet, and note how long it takes to bring about this wetting. Such examination can be made either by means of a long-shafted posthole auger or two- inch carpenter's auger; or more quickly, after some practice has been acquired, by the use of a pointed prod made of quarter-inch square steel, with a loop for a cross-handle, which can be pushed down by twristing it slightly alternately in opposite directions. This rod also serves admirably for preliminary tests of the subsoil in the examination of lands.

Drainage. — The natural slope of these lands toward Mesquit Lake, as shown by the contour lines of the map, together with the good percola- tive power of the lighter silty and sandy lands, renders the leashing of their salts into drainage ditches running toward the lake perfectly feasible, and simplifies the problem of ultimate successful cultivation.*

*In studying the contour lines on the map it should be noted that the small figures appearing on these lines do not indicate directly the elevation above the sea, but only the relative altitude of the several points. The point of reference used is 1,000 feet above sea level, and the true altitude (or rather depression) can be found by deducting 1,000 from these figures.

— 40 —

For the permanent betterment of the lands, those interested should, by community action, devise a thorough system of drainage. Such a system might at the beginning be a number of deep ditches, into which the alkali-charged seepage-water could enter from flooded areas, until the far preferable plan of tiling could be profitably introduced.

An illustration in point obtains in the case of the Patterson ranch, at Oxnard, a portion of which became much " salt-stricken," but where, after the construction of a deep drainage canal into which were led laterals, there was, and is, a constant removal of the accumulated salts at a surprisingly rapid rate.

VEGETATIVE CHARACTERISTICS OF THE S ALTON BASIN.

That the vegetation of any region supplies important information concerning its agricultural adaptations is so well known in practice as not to require discussion. It is especially instructive in its application to alkali lands; and Mr. Snow was therefore instructed to observe and collect for determination specimens of all the plants to be found on the territory explored by him.

"While the adaptation or non-adaptation of particular alkali lands to certain cultures may be determined by sampling the soil and subject- ing the leachings to chemical analysis, it is obviously desirable that some other means, if possible available to the farmer himself, should be found to determine the reclaimability and adaptation of such lands for general or special cultures. The natural plant growth seems to afford 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 preeminently the presence of common salt; the presence or absence of still others forms 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 talked about almost everywhere; but the meaning of this term — i. e., the kind of plant desig- nated thereby — varies materially from place to place, according to climate as well as to the quality of the soil. Yet if these characteristic plants could be 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 districts, 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 reference to this Station." *

The season at which the exploration took place (Christmas vacation)

* Bulletin No. 128, California Experiment Station, p. 35.

— 41 —

was of course unfavorable to the finding of all the kinds of plants that might occur somewhat later. Only twenty-two species in all were col- lected, and these were submitted for determination to Mr. Joseph Burtt Davy, Assistant Botanist to the Station. Mr. Davy's results and com- ments are given herewith, together with the annotations of Mr. Snow, placed in brackets.

ANNOTATED LIST OF PLANTS FROM THE SALTON BASIN.

(Collected by F. J. Snow.) By Jos. Burtt Davy, Assistant Botanist.

CRUCIFERiE.

1. Lepidium lasiocarpum, Nutt. Pepper-cress.

Five miles south of proposed townsite. [Very abundant near Mexican line.]

Salton River, near Patton's camp. [Abundant in scattering places.]

T. 13, R. 15. [Scarce, except in small patches.]

Mexico: 15 miles from line. [Scarce.]

A common desert annual, probably tolerant of some alkali, as are many other species of the genus, but not necessarily indicative. It is sometimes found also in moist alluvial soils, and ranges from Santa Barbara through the Mojave plateau region and, east of the Sierra, northward to Keeler.

ZYGOPHYLLACEiE.

2. Larrea tridentata ( DC .) Coville. Creosote-bush.

Along Salton River. [Abundant in places along the river. Very abundant toward Mexican line.]

Locality 9, T. 13, R. 15. [A few scattering live bushes.]

Mexico: 15 miles from line. [A few bushes. Becomes very abundant near Mexican line along Salton River.]

One of the most characteristic desert plants, occurring almost throughout the Lower Sonoran zone from the bottom of Death Valley about 300 feet below sea level to an altitude of 5,500 feet in the Panamint Mountains. It is not an alkali plant, and usually grows on well-drained soils well above the alkali line ; but at its lower limit a few scattered specimens are often found in the Atriplex polycarpa belt, in a mixture of gravel and clay with some visible trace of alkali.

LEGUMINOS.E.

3. Astragalus mortoni, Nutt. Morton's loco-weed; ' ' Loco- weed " ; " Wild pea."

Salton River bed; "if cattle eat, will go crazy." [Scattering plants along the river-bed.] New River bed. [A number of plants near north end of river-bed.]

Moist grounds along the eastern base of the Sierra Nevada, in the vicinity of Mono Lake, and northward to the interior of Oregon and Utah. Well known as " a deadly sheep poison." We have no information as to its tolerance of alkali, but other species of the genus are characteristic alkali plants.

4. Prosopis juliflora (Swartz) DC. Mesquit-tree ; Algaroba; Honey mesquit.

Near Mexican line— a few miles from Blue Lakes. [Abundant.]

Characteristic of desert areas with moist subsoil. It sometimes occurs on the edge of alkali marshes in company with Atriplex canescens and Sueeda suffrutescens, where a slight alkali efflorescence or thin crust occurs, but above the heavily alkaline soils, though below the Atriplex polycarpa belt. I have found it in somewhat alkaline soils near Bakersfield. Though tolerant of some alkali, it is not an alkali indicator. Its altitudinal range varies from 328 feet below sea level, to 5,650 feet above.

— 42 —

FICOIDE^E.

5. Sesuvium portulacastrum, L. Lowland purslane.

New River channel. [Found at the north end of New River channel; but few plants to be seen elsewhere.)

A very characteristic plant of moist alkali and saltmarsh soils both in the interior and along the seacoast. It is found in alkali marshes in the Mojave Desert and the. Tulare Valley, and in the Great Basin region from northern Nevada to Colorado and New Mexico. It is said that in the interior it often occurs with much broader leaves than is usual when growing along the seashore. We have no analysis showing the tolerance of alkali by this plant, but it has been found growing in soils so heavily impregnated with salts that scarcely any other plants grew there.

COMPOSITE.

6. Bigelovia veneta (H. B. K.) Gray. Bigelovia.

Ten miles south of Blue Lakes. [Abundant.]

Alkali meadow at monument east of Salton River. [Abundant.]

A plant of the Lower Sonoran zone, common in moist alkali soils, but apparently not tolerant of a very large percentage. In the Bakersfield region the salt tolerance of this plant was found to vary from 1,800 pounds of salts per acre to 24,320 pounds. It was not found in soils heavily charged with alkali.

7. Baccharis sp. (imperfect material). Sausal; Baccharis ; (also Arrow-wood, in part).

Salton River bed. [Found only in river-bed in numerous places.]

Our species of Baccharis are swamp plants, usually growing on the borders of rivers and streams or in "washes." As* a rule they are found in fresh water, but at least one species (not this one) sometimes occurs in slightly alkaline water. Two other species, B. emoryi, Gray, and B. sergiloides, Gray (to neither of which does the specimen appear to belong), occur in the Colorado Desert region.

8. Pluchea sericea (Nutt.) Coville. Cachimilla ; Arrow-wood.

Salton River bed. \

New River. v [Abundant along portions of the river channels and banks.]

New River channel. )

T. 13, R. 15. [Scarce.]

i

Reported as occurring along sandy borders of streams from Ventura County eastward to Utah and south through Arizona to New Mexico. Both of our species of Pluchea frequent 'moist alkali swamps, and one of them occurs both in the interior in the Suisun marshes and in the saltmarshes of San Francisco Bay. The amount of alkali tolerated is evidently considerable, as P. sericea occurs in associa- tion with Alkali tussock-grass (Sporobolus airoides (Torr.) Thurb.) and Salt-grass (Distichlis spicata (L.) Greene) in the Mojave Desert plateau region.

HYDROPHYLLACEvE.

9. Natna hispidum, Benth.

Salton River bed. [Scarce, except in certain portions of the river-bed.]

A desert annual, apparently restricted to the Colorado Desert, and probably not indicative of alkali.

BORAGINACE.E.

10. Coldenia palmeri, Gray.

Sample 10, T. 13, R. 16. [O-ri sandy, high lands. Not very abundant.]

A dwarf, desert perennial occurring on sand-hills along the Colorado and lower part of the Mojave and adjacent Arizona. (Bot. Calif.)

11. Heliotr opium curassavicum, L. Wild heliotrope.

Along Salton. \

New River. - [Abundant along the river-bed.]

New River channel. )

Alkali meadow at monument east of Salton River. [Abundant.]

A nearly cosmopolitan weed, common in sands of the seashore, and in moist alkaline soils of the interior. It generally indicates the presence of alkali and moisture, but is sometimes found in soils apparently free from alkali.

— 43 —

AMARANTACE.E.

12. A marantus chlorostachys, Willd. Pigweed.

Salton River near Patton's camp. [Scattering dead plants, with here and there live plants of rank growth. To the west, about 2 miles, they thrive and attain a very rank growth. It is also found east of Salton River near the Mexican line.]

A semi-tropical weed, probably naturalized.

13. A marantus palmeri, Wats. (?)

Sample 11, T. 13, R. 15. [Scattering plants; abundant toward the Mexican line. J

A desert species, apparently indigenous to the Colorado Desert and Rio Grande regions. The Amaranths are such omnivorous, weedy plants that they can not bt relied upon as alkali indicators.

CHENOPODIACEJE.

14. Atriplex lentiformis (Torr.) Wats. Lens-fruited saltbush.

New River. [Found scattered in New River country ; abundant in places and in river-bed.]

Mexico: 15 miles from line. [Scarce in this locality ; but abundant near Mexican line.]

Alkali meadow at monument east of Salton River. [Abundant.]

A desert species, ranging from the Tulare Valley to the Colorado Desert and east- ward through Arizona. We have no record as to its tolerance of alkali, but the list of localities in which it has been found and the plants with which it is associated, indicate that it is an alkali plant.

15. Atriplex polycarpa (Torr.) Wats. Scrub saltbush: called " Greasewood" in the

Mojave Desert, but not the " Greasewood " of the Great Basin region. Mexico : 15 miles from line. [Abundant in certain localities near Mexican line.]

A characteristic desert species, ranging through the Lower Sonoran zone from the Tulare Valley through the Mojave and Colorado deserts to the Williams River in Arizona. Common in clayey valley bottoms, usually in dry soils. Analyses of scrub saltbush soils near Bakersfield show that its tolerance of salts ranges from 840 pounds to 78,000 pounds per acre.

16. Atriplex canescens (Pursh) James. Shad scale; sometimes called "greasewood."

Sample 9, T. 13, R. 15. [Many dead bushes on small hummocks. A few live

bushes, which are very large, are found scattered near.] Sample 11, T. 13. R. 15. [Many dead bushes are found in this vicinity.] T. 13, R. 15. [Many dead bushes on small hummocks ; also scattering live

bushes.] Near Mexican line, a few miles from Blue Lakes. [Abundant near the lake.] Mexico : 15 miles from line. [Scarce ; but very abundant near the line on Salton

River.]

A common and characteristic species, occurring in dry soils both ifi the Upper and Lower Sonoran zones in the Mojave and Colorado deserts, and in the Great Basin region from northern Nevada and Colorado to New Mexico. It does not appear to reach the Tulare Valley. It occurs in dry soils, on mountain slopes at altitudes ranging between 2,300 and 4,700 feet, and does not seem to be indicative of the presence of alkali. Like the Mesquit and Creosote-bush, it is sometimes found sparingly in slightly alkaline soils at its lower limit.

17. Atriplex sp. (immature).

Sample 8, T. 11, R. 14. [A few scattering dead bushes.]

Sample 9, T. 13, R. 15. [Dead bushes are found on small hummocks.]

18. Suseda sp. (immature). Saltwort; Glasswort.

Salton River bed. [Abundant along the river-bed.] New River. [Abundant along the river-bed.]

The saltworts are characteristic alkali indicators, and are not known to occur elsewhere than in moist alkali soils. The total amount of salts tolerated has a wide range of variation, running from 3,700 pounds to 153,000 pounds per acre; but

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saltwort has been found in greatest luxuriance where the total amount of salts was 130,000 pounds per acre. The saltworts appreciate more common salt (sodium chlorid) than many other characteristic alkali plants, but appear to be somewhat easily affected by salsoda (sodium carbonate).

POLYGONACE.E.

19. Rumex sp. (immature). Dock.

Along Salton. [Abundant in places along the river bank.] Salton River bed. [Abundant in places along the river-bed. J At monument east of Salton River. [Abundant.]

Two or three species are found in moist places in tbe Mojave and Colorado deserts.

GRAMINE.E (TRUE GRASSES).

20. Leptochloa imbricata, Thurb. Alkali slender-grass.

Near Salton River bed, 15 miles from line. [Not abundant.]

Common in moist places and alkali plains from the Tulare Valley through the Colorado Desert to Lower California, and eastward into Mexico and Texas. A somewhat stout perennial, 1 to 3 feet high, " abundant in fields and gardens, thrifty on alkali plains and near soft [salt?] water; abundant in August and September, when alfalfa is dried up ; a good forage plant, cut and fed to animals." {Dr. Ed. Palmer.)

GNETACE^E.

21. Ephedra sp. (immature).

Ten miles from Blue Lakes. [Abundant near the lake and along New River near the Mexican line.] Characteristic desert shrubs, said to be sometimes found in alkali soils.

UNCLASSIFIED.

22. Dwarf annual (immature and not recognized).

Sample 8, T. 11, R. 14. [Only a few plants to be found.] * Sample 9, T. 13, R. 15. [Only a few plants to be found.]

The list of plants here given is notable for the absence of most of the species considered elsewhere as prominent alkali indicators. We miss at once the salt- or alkali-grass (Distichlis), the "greasewood" of Nevada (Sarcobatus) and that of the San Joaquin Valley (Allenrolfea), the samphire (Salicornia), and the tussock-grass (Sporobolus airoides). Of the saltbushes proper (Atriplex)y two (A. polycarpa and lentiformis) appear elsewhere as species indicating the probable presence of consider- able alkali, while the other two species observed are not known as alkali plants. The two plants that may be considered as indicators of strong alkali, especially of common salt, are the saltwort {Suzeda) and the lowland purslane (Sesuvium); their indication is strengthened by their occurence in the river channels, at whose level the profiles (pp. 20 and 21) show an abundance of salt. But as a whole, the collection made does not speak of "irreclaimable" alkali land, so far as we know their habits. The heliotrope will grow luxuriantly in non-saline lands, but also where common salt can be seen by the seaside. The creosote bush (Larrea), the pepper-cress (Lepidium), the pigweeds (Amarantus), the Bigelovia (yellow-flowered, sometimes called green sage) are not plants addicted to alkali lands. Taken as a whole, the native vegetation does not altogether confirm the unfavorable impression derived from the leach-

— 45 —

ing of the soil samples. It is hoped that a more detailed examination of the flora at a more favorable season, soon to be undertaken, will throw more light on these questions.

( !LIMATE OF THE SALTON BASIN.

The high summer temperature and dryness of the air in the Salton region are well known, being in this respect similar to the rest of the Colorado Desert. While the thermometer during summer usually rises to and above 100° Fahr. (124° having been recorded twice at Salton during 1901), the heat is not oppressive, on account of the dryness of the air, which evaporates the perspiration as soon as formed. The nights are usually decidedly cool to the sensation. The winter temperatures are in strong contrast to the summer heat, as will be seen from the small table, given below, of observations made by Mr. Snow during December, 1900, and January, 1901. It will be noted that a minimum temperature of 13° occurred on January 2d, so that ice two inches thick formed near camp. Such a temperature would at once prohibit the culture of citrus fruits, but may occur only locally, on low ground. Still, the run of December temperatures, from observations all over the region, indicates clearly that " semi-tropic" growths will incur consid- erable risks, unless protected in winter.

Morning Temperatures Observed in Salton Basin at 8 o'clock.

1900. 1900. 1901.

Dec. 22 23° Dec. 27 21° Jan. 1 .... 38°

23 *21 28 25 2 13

23 t70 28 tt73 3§ 23

24 }24 29 28 4 30

25 23 30 .... 26 5 40

26 20 31 24 6 30

* Dec. 23. Ice in washpan and on pond two inches thick. f Dec. 23. For the day.

J Dec. 24, 25, 26, and 27. Ice in ponds. ft Dec. 28. For the day.

§ Jan. 3. Surveyors' Camp 17.

CROPS FOR THE SALTON BASIN.

As to crops for the silt soils of this region, it must be said that the show- ing here made is not at all encouraging for extensive fruit-growing at the present time. While there may be localities in the region which could grow the fruits more tolerant of alkali and dry heat, yet we deem it un- wise at present to encourage the planting of fruit, except the date-palm, to any considerable extent. The date-palm would doubtless be one of the fruits which could be most successfully grown, taking into consideration both the climate and the alkali soils. To this might be added olives, figs, table, sherry, and port grapes; and on the sandier lands, almonds,

— 46 —

peaches, and some of the Japanese plums (all on Myrobalan stock) might be grown. Of ordinary crops, alfalfa, barley, sorghum, and beets for stock food, together with the saltbushes, are those that will be most likely to succeed before drainage to carry off the alkali salts has been made effective. Among the vegetables, the egg-plant, melons, cucumber, carrot, celery, asparagus, onion, sea-kale, and New Zealand spinach are those most likely to succeed.

It must not be forgotten that high summer temperature will militate materially against the production of the ordinary deciduous fruits, even after the lands have been successfully leached of their alkali to the extent necessary to permit the growth of such trees. The effects of hot northers upon these trees in other parts of the State indicate plainly what is likely to be the effect of the normal atmospheric conditions of the Colorado Desert upon them. ' The cultural experience had at Indio will be valuable in determining the reasonable prospects for successful culture of several crops, always keeping in mind that the light sandy soils of that portion of the region, containing but little alkali and easily leached of what there is by flooding, are more easily handled than those of the alluvial area here in question.

The following list of possible crops for alkali soils has been compiled by Mr. Joseph Burtt Davy, Assistant Botanist of the Station. It should be understood that while the plants mentioned in this list are all more or less alkali-resistant, yet the extreme climatic conditions existing in the Salton Basin render the actual success of many very questionable, although worthy of trial. The " toleration" list will aid in making selections for experiment.

POSSIBLE CROPS FOR ALKALI SOILS.

EDIBLE FRUITS.

Strawberry tomato (Physalis pubescens, L.).

Cape gooseberry (Physalis peruviana, L.).

Date-palm (Phcenix dactylifera, L.). In Arabia it is said to grow in soil " strongly impregnated witb salt," and that "the water for irrigation may be slightly brack- ish."

Oleaster (Elseagnus augustifolia orientalis, Schlecht). Produces the fruit known as " Trebizonde dates."

Olive (Oka europsea, L.). The Mission variety should be first tried.

Black mulberry (Morris nigra, L.). The Black Persian is probably derived from this species. It is likely that other species, also, would tolerate alkali.

Grape (Vitis vinifera, L.), especially the southern (sherry and port) varieties.

Golden currant (Ribes aureum, Pursh.) is said to tolerate an alkaline soil. It is also known as the Missouri, Utah, Utah hybrid, and Buffalo currant. The best cultivated varieties are said to be the "Crandall," " Deseret," and "Jelly." It is doubtful if it will resist the dry heat of the Salton Basin.

Alkali currant (Ribes aureum tenuiforum (Lindl.) Torr.). Grows in strongly saline soil in Washington, Oregon, northern California, and Nevada.

Fig (Ficus carica, L.).

VEGETABLES.

Jerusalem artichoke (Helianthus tubero- sus, L.). The white variety is said to be the best for alkali soils.

Beet-root (Beta vulgaris hortensis).

Carrot (Daucus carota, L.).

— 47

Spinach (Spinacia oleracea, L.). (Medium alkali.)

Radish (Raphanus sativus, L.).

Celery (Apium graveolens, L.).

Celeriac (Apium graveolens rapaceum, DC.).

Asparagus (Asparagus officinalis, L.).

Onion (Allium cepa, L.).

Swiss chard (Beta vulgaris cicla).

Globe artichoke (Cynara scolymus, L.).

Cardoon (Cynara car dunculus, L.).

Tomato (Ly coper sicum esculentum, Mill.) ; worth trial.

Egg-plant (Solanum melongena, L.). Very hardy against dry heat.

Sea-kale (Crambe maritima, L.).

Garden cress (Lepidium sativum,, L.).

Roselle (Hibiscus sabdariffa, L.).

New Zealand spinach (Tetragonia e.r- pansa, Murr.).

Quinoa (Chenopodium quinoa, Willd.). The foliage makes a savorv and whole-

some greens.

STARCH FOODS.

Quinoa (Chenopodium quinoa, Willd.). The seeds form one of the most important foodstuffs of the inhabitants of Peru and Chile, who make a nutritious porridge of it.

SUGAR CROPS.

Sugar-beet ( Beta vulgaris altissima). Sugar sorghum (Andropogon sorghum sac- charatus (L.) Kcern).

OIL PLANTS.

Russian sunflower (Helianthus annuus, L.).

Niger seed (Guizotia abyssinica, Cass.). This plant is worth a trial on alkali soils.

FORAGE PLANTS.

Root crops:

Jerusalem artichoke (Helianthus tubero- sus, L.). Valuable tuber for hogs. The white variety seems to be better adapted for alkali soils than the red.

Mangold-wurzel (Beta vulgaris rapa).

Seed crops:

Russian sunflower (Helianthus annuus, L.). The seeds furnish a valuable poultry food. The sunflower is reported to endure the excessive summer heat of central Aus- tralia better than any other cultivated herb tried there. The wild form of this plant (indigenous to California) has been found to tolerate easily 12,500 pounds of salts in an acre-foot at Chino.

Barley (Hordeum vulgare, L.).

Japanese barnyard millet (Panicum crus- galli maximum, Hort.).

Pasture, soiling, and hay plants:

Alfalfa (Medicago sativa, L.).

Saltbushes (Atriplex semibaccata, R.Br.; A. leptocarpa, F.v.M. ; A. vesicaria, How- ard ; A. kochiana, Maiden ; A. spongiosa, F.v.M. ; A. halimoides, Lindl. ; A. holocarpa, F.v.M., and A.campanulata, Benth. ; Kochia aphylla, R.Br., and K. pyramidata, Benth. ; Rhagodia billardieri, R.Br.; R. parabolica, R.Br.; R. hastata, R.Br., and jR. linifolia, R.Br. ; Sclerolsena bicornis, Lindl.).

Modiola (Modiola decumbens, G. Don).

New Zealand spinach (Tetragonia ex- pansa, Murray).

Slough-grass (Beckmannia erucseformis , Host.).

Alkali tussock-grass (Sporobolus airoides (Torr.) Thurb.)

Alkali slender-grass (Leptochloa imbri- cata, Thurb.).

Saccaton (Sporobolus wrigh{ii, Munro).

Alkali saccaton (Panicum bulbosum, H. B. K.).

Salt-grass (Distichlis spicata (L.) Greene).

Alkali lyme-grass (Elymus salinus, Jones).

Barnyard-grass (Panicum crusgalli, L.).

Japanese barnyard millet (Panicum crus- galli maximum, Hort.).

Switch-grass (Panicum virgatum, L.).

Nevada blue-grass (Poa nevadensis, Vasey).

Mexican salt-grass (Eragrostis obtusiflora^ Scribn.).

Wild rye (Elymus condensatus, Presl.).

Meadow barlev-grass (Hordeum nodosum, L.).

Little barley-grass (Hordeum pusillum, Nutt.).

Creeping bent-grass (Agrostis alba stoloni- fera).

Kaffir corn, Jerusalem corn, Durra, and Milo maize (Andropogon sorghum sativus, Hack.).

Egyptian corn (Andropogon sorghum cer- nuus, Kcern).

Teosinte (Euchlsena luxurians (Durieu) Aschers).

Usar-grass (Sporobolus orientalis, Kth.).

Purslane (Portulaca, oleracea, L.).

Bulbous-rooted foxtail (Alopecurus bul- bosiis, Huds.).

Korean lawn-grass (Zoysia pungens, Willd.).

Barley (Hordeum vulgare, L.).

Bermuda-grass (Cynodon dactylon (L.) Pers.).

Quitch-grass (Agropyron repens, Beauv.).

Johnson-grass (Andropogon halepensis (L.)Brot.).

48

The three last-named grasses ( Bermuda- grass, Quitch-grass, and Johnson-grass) are liable to become terrible weeds in cultivated ground, and should not be planted where there is any danger of their spreading among orchards or cultivated crops, nor, in fact, in any place which is not to be given up entirely and permanently to pasture.

Browsing shrubs:

Tea-tree (Leptospermnm lanigerum, Smith).

Myalls (Acacia homalophylla, Cunn., and A. pendula, Cunn.).

Shrubby saltbushes (Atriplex nummula- ria, Lindl. ; A.pamparum, Griseb. ; Bhagodia spinescens inermis).

PAPER-MAKING MATERIALS.

Esparto-grass (Stipa tenacissima, L.). Albardin (Lygeum sparttim, L.).

SHADE AND ORNAMENTAL TREES AND SHRUBS.

Kazlreuteria paniculata, Laxm.

Acacia pendula, Cunn.

Acacia homalophylla, Cunn.

Albizzia lophantha, Benth.

Albizzia lebbek, Benth.

Canary date-palm (Phoenix canariensis, Hort.).

Washington palm ( Washing tonia filifera, Wendl.).

Oriental sycamore (Platanus orientalis, L.).

Manna gum (Eucalyptus viminalis, Labill.).

Peppermint gum (Eucalyptus amygdalina, Labill.).

Red gum (Eucalyptus rostrata, Schlecht.).

Yate tree (Eucalyptus cornuta, Labill.).

It should be borne in mind that these several plants are not equally tolerant of alkali, and that local experimentation is necessary in order to determine the adaptation of each one to local conditions.

TOLERANCE OF VARIOUS CROPS FOR ALKALI SALTS.

The subjoined table, originally published in Bulletin No. 133 of this Station, is of interest in connection with the discussion of the avail- ability of the Salton Basin lands for cultural purposes. For comparison with other publications it should be remembered that the calculation of the " pounds per acre," most readily understood by farmers, is based on the estimated weight of an acre-foot of soil at four millions of pounds. Hence, one per cent is equal to 40,000 pounds; one-tenth of one per cent, 4,000 pounds. It will be noted that the total of salts alone is but a very rough criterion of the possibilities of culture, on account of the very different effects of the several compounds on plants. The sul- fates (of potash, soda, and magnesia) are the least injurious, and happily predominate widely in the Salton Basin. Carbonate of soda, though very injurious as such, is easily transformed into the bland sulfate by dressings of gypsum. Common salt is really the worst ingredient.

49

Highest Amount of Alkali in Which Fruit Trees Were Found Unaffected.

Arranged from highest to lowest. Pounds per acre in four feet depth.

Sulfates (Glauber Salt).

Carbonate (Salsoda).

Chlorid (Common Salt).

Total Alkali.

Grapes 40,800

Olives 30,640

Figs 24,480

Almonds 22,720

Oranges 18,600

Pears 17,800

Apples 14,240

Peaches 9,600

Prunes 9,240

Apricots 8,640

Lemons 4,480

Mulberry 3,360

Grapes 7,550

Oranges 3,840

Olives 2,880

Pears... 1,760

Almonds 1,440

Prunes 1,360

Figs 1,120

Peaches 680

Apples 640

Apricots 480

Lemons 480

Mulberry..-. 160

Grapes 9,640

Olives 6,640

Oranges 3,360

Almonds .... 2,400

Mulberry.... 2,240

Pears... 1,360

Apples 1,240

Prunes 1,200

Peaches 1,000

Apricots .. 960

Lemons 800

Figs 800

Grapes 45,760

Olives 40,160

Almonds 26,560

Figs --. 26,400

Oranges 21,840

Pears 20,920

Apples 16,120

Prunes 11,800

Peaches 11,280

Apricots 10,080

Lemons 5,760

Mulberry 5,760

Other Trees.

Kolreuteria .. 51,040	Kolreuteria - .	9,920	Or. Sycamore 20,320	Kolreuteria. ._	73,600
Eucal. am.. .. 34,720	Or. Sycamore	3,200	Kolreuteria.. 12,640	Or. Sycamore.	42,760
Or. Sycamore. 19,240	Date Palms..	2,800	Eucal. am. .. 2,960		40,400
Wash. Palms. 13,040	Eucal. am. ..	2,720	Camph. Tree. 1,420	Wash. Palms.	15,280
Date Palms .. 5,500	Wash. Palms	1,200	Wash. Palms 1,040	Date Palms...	8,320
Camph. Tree. 5,280	Camph. Tree.	320		Camph. Tree..	7,020

Small Cultures.

Saltbush 125,640

Alfalfa, old.. .102,480 Alfalfa, young 11,120 Hairy Vetch.. 63,720

Sorghum 61,840

Sugar Beet... 52,640

Sunflower 52,640

Radish. 51,880

Artichoke 38,720

Carrot 24,880

Gluten Wheat 20,960

Wheat 15,120

Barley 12,020

Goat's Rue... 10,880

Rye 9,800

Canaigre 9,160

Ray Grass 6,920

Modiola.. .. 6,800 Bur Clover... 5,700

Lupin .. 5,440

White Melilot 4,920 Celery 4,080

Saltbush 18,560

Barley 12,170

Bur Clover .. 11,300

Sorghum 9,840

Radish 8,720

Modiola 4,760

Sugar Beet.. 4,000

GlutenWheat 3,000

Artichoke... 2,760

Lupin 2,720

Hairy Vetch. 2,480

Alfalfa 2,360

Grasses 2,300

Kaffir Corn .. 1,800

Sweet Corn.. 1,800

Sunflower ... 1,760

Wheat 1,480

Carrot 1,240

Rye 960

Goat's Rue .. 760 White Melilot 480

Canaigre 120

Modiola 40,860

Saltbush 12,520

Sorghum .... 9,680

Celery 9,600

Alfalfa, old.. 5,760

Alfalfa, yo'ng 760

Sunflower... 5,440

Sugar Beet ._ 5,440

Barley 5,100

Hairy Vetch. 3,160

Lupin 3,040

Carrot 2,360

Radish 2,240

Rye.. 1,720

Artichoke... 1,480

GlutenWheat 1,480

Wheat 1,160

Grasses 1,000

White Melilot 440

Goat's Rue .. 160

Canaigre 80

Saltbush 156,720

Alfalfa, old... 110,320 Alfalfa, young 13,120

Sorghum 81,360

Hairy Vetch.. 69,360

Radish 62,840

Sunflower .... 59,840 Sugar Beet ... 59,840

Modiola 52,420

Artichoke .... 42,960

Carrot 28,480

Barley 25,520

Gluten Wheat 24,320

Wheat 17,280

Bur Clover.... 17,000

Celery 13,680

Rye 12,480

Goat's Rue ... 11,800

Lupin 11,200

Canaigre 9,360

Ray Grass.... 6,920 White Melilot 5,840

4— Bul. 140

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JANUARY CROP REPORTS FROM ACTUAL SETTLERS.

Reports have been received from sections 19 and 20, in township 14

south, range 15 east, sections 29, 32, and 33, in township 16 south, range

14 east, and on land adjoining the town of Imperial on the south.

They show apparent success, during the past season, in growing alfalfa,

sorghum, barley, millet, Kaffir corn, and watermelons, with a few lesser

tracts of garden vegetables. As an illustration of the tone of these

reports, we present the following extract from a letter received from

Thomas Beach, Calexico; a region which, however, is outside of the

worst clay and alkali belts:

" Between the last of June and middle of August of last year I put in about 325 acres of sorghum, 30 of millet, 20 of field corn, 25 of Kaffir corn, 2 of melons, 1 of cotton, and 1 acre of pumpkins. The sorghum was watered six times and the others about four. The former gave about 5 tons per acre, and the millet yielded 2 tons ; the corn did not do as well. I raised some Rocky Ford melons from seed ripened the same year at Indio, and can say that I never tasted better; the same is true of watermelons and pumpkins. The ground took water well, and during the summer months I was able to disc it three days after flooding. I now (January 28th) have barley 2 feet high that has been watered but twice ; some alfalfa I sowed on the 20th of September is up 6 or 8 inches in height, with roots a foot long and has had but two irrigations."

These reports do not in any sense contradict the facts stated in the earlier pages of this report; for it will be noted in the first place that these are, in nearly every case, alkali-resistant crops.

Upon inspection of the maps and tables it will be further seen that, in general, the first foot of soil does not carry the heavy percentage of alkali which exists at a depth of two to three feet. An irrigation, either just preceding or just following seeding, would tend to temporarily reduce the alkali in this upper foot even below the amount shown in the tables, and below the maximum tolerance of the essentially alkali- resistant plants named above; and probably also below that for many of much less resistant kinds. There is little doubt that, at the outset, most plants climatically adapted could be started with more or less success under the common methods of irrigation. These early results can only be taken as indicating that the alkali in the top foot at this time and in those localities was not sufficiently strong to interfere seriously with the germination of seed — retardation possibly excepted.

The reports can not, however, be taken as indicative of what may be expected after surface irrigation has been practiced for a few years; for such treatment is sure to result in the rise of alkali to such an extent as to cause serious injury to the crop and consequent financial loss to the grower.

Mention has already been made of the alkali-resistant nature of these crops, except millet and watermelons. In the case of the former, which is closely related to sorghum, it may be expected to be quite resistant, although no figures are at hand touching upon the matter; the water-

— 51 —

melon is essentially a desert plant, related plants being indigenous to the African deserts. The growth of these crops in these localities simply adds weight to the evidence that these plants are quite tolerant of alkali.

People should not be deceived by a rank growth of plants in arid regions, unless the characteristics of such plants be definitely known; for the very fact of the existence of alkali is evidence of intrinsic fertility of the soils, and crops are well known to have a luxuriant growth on such lands, provided only that the saline matter is not present to such an extent as to approach the limit of tolerance of the crops grown.

Notwithstanding the present success with the alkali-resistant crops named, residents are urged to adopt the methods laid down in this publication as those which alone may reasonably be expected to give immunity from alkali damage for any considerable length of time.