South of the Bay Region.

Santa Clara Valley. This valley, reaching from the bay of San Francisco southward for 70 miles into San Benito County, has a variety of soils. Around the bay back from the salt marshes is a black clay adobe, a column of which was taken from the Morse Seed Farm near Santa Clara. The soil contained 4.43 per cent of humus, which is the highest we have found in any of the soils of the State except the marsh lands. South of San José the lands are more loamy in character and are represented by a column taken from near Gilroy, by F. E. Johnson. The valley west of San José has a soil more sandy in nature and more or less gravelly, on which are located extensive orchards. A column of this soil, seemingly representative of this land, was taken from the El Quito ranch, south of Saratoga.

Pajaro Valley. The soil of the valley proper is a dark loam, while along the river are adobe clays and clay loams, the latter being devoted to sugar beet culture. The valley loam is alone represented in the soil column series. It was taken from the apple-growing section on the Watsonville side of the valley. Another column of soil was taken from Watsonville heights one mile northwest of the town. At eight feet depth a mass of decomposed granite was reached. Both columns were taken by F. E. Johnson.

Salinas Valley. The lower or northern part of the valley for about 50 miles is from 8 to 12 miles wide, but to southward the valley is very narrow. Two classes of soil are represented in the series. A column of 15 feet from the sandy loam lands of the west side of the Salinas River was taken at Fort Romie near Soledad; and a column of the black adobe lands around King City, Monterey County, was kindly sent by Mr. R. L. Adams, formerly of the Spreckels Sugar Beet Company.

more.

Arroyo Grande Valley. The soil of this narrow but important valley is of a dark and heavy clay-loam nature to the depth of twelve feet and Two columns were obtained by F. E. Johnson, one near the town of Arroyo Grande, the other from the farm of the Routzahn Seed Company a few miles to the westward, the only apparent difference being a darker color in the surface foot of the seed-farm soil.

Santa Maria Valley. The soil is chiefly a sandy loam of a brownish color and very deep. A column was taken by F. E. Johnson near the sugar beet fields west of the town of Santa Maria.

Lompoc Valley. Three chief classes of soils occupy the valley; adobe near the hills, sandy alluvium near Santa Ynez River, and an intermediate type of clay loam between them. The Burpee seed-farm is situated on the clay loam lands, and a column of soil was taken there to a depth of 12 feet, when water was reached.

HUMUS AND HUMUS-NITROGEN IN VALLEY LANDS OF THE COAST RANGE REGION. North of the Bay Region.

The soils of the valleys of the Coast Range are remarkably high in their humus content when compared with the other soils of the arid region. The general average of the State is 1.25 per cent in the surface soil, while that for these coast valleys is 1.94 per cent. But especially does this difference appear when we note the many individual soils in which 1 per cent of humus is found at depths of four, five and even seven feet. In nearly all of the columns there is a decrease downward, indicating that the humification was of plant roots rather than of vegetable matter deposited from overflow as the land was being built up.

A comparison of the average amounts of humus in the soils of the three divisions shows that the lands of the valleys north and south of the bay region are richer than those on the east, both in the surface foot, the upper three feet, and in the depth of twelve feet. Santa Clara and Arroyo Grande valleys have the highest percentages in the first and the upper three feet, while Arroyo Grande and Lompoc valleys stand first as regards the entire depth of twelve feet.

It is interesting to note that Russian River Valley on the north and these three valleys on the south have averages of more than one per cent for the entire depth of twelve feet, the only instances of this among all of the soils of the State thus far examined excepting the tule marshes. It is also to be noted that all of the valleys of this group of sixteen,

except Livermore and Salinas, have averages of more than one per cent of humus in the upper three feet, and that Santa Clara and Arroyo Grande have more than two per cent each.

The percentage of nitrogen in the first foot is highest in the valley of Arroyo Grande, .16 per cent or approximately 6,400 pounds per acre. Los Guillocos, Vaca and Lompoc valleys have .13 per cent each, Sonoma, Napa and Santa Maria, .11 per cent each, and Santa Clara has .10 per cent, while all others have less. Among the individual soils, Gilroy has .15 per cent and Berkeley .14 per cent.

In the upper three feet, Arroyo Grande and Guillocos valleys are the richest in nitrogen, the approximate amount being 12,000 pounds per acre in the three feet.

SOIL COLUMNS OF THE SOUTHERN CALIFORNIA REGION.

The region known as Southern California embraces that part of the State lying south of the Sierra Madre Mountains, and includes a number of large and fertile valleys and plains.

Saticoy Plain. The long and broad slope in Ventura County, reaching from the mountains southward to the sea shore and noted for its lima bean culture, is represented by two soil columns, one taken by J. B. Neff from near Mound Schoolhouse a few miles east of Ventura, and the other from the orange grove of Mr. N. B. Blanchard, at Santa Paula.

Santa Clara River Delta. This comprises a broad region of gray alluvial land, and contains more or less alkali salts in places. Water is usually found at a depth of 8 or 10 feet below the surface. The delta is noted for its sugar-beet culture. A column was taken near Springville by J. B. Neff to a depth of 8 feet, where water was reached.

Pleasant Valley Hill Slope. This column was taken from the sandy slope of the hills north of the Southern Pacific Railroad station at Camarillo, on the property of the Citrus Farms Company.

San Fernando Valley. The valley of San Fernando lies north of Los Angeles and includes about 200 square miles. Much of the valley on the east is covered by débris of cobblestones, gravel sand washed from the canyons on the northeast, but the rest of the valley has sandy and sandy loam soils, with some heavier clays on the south.

Two columns were obtained by F. E. Johnson: one from the sandy lands about one half mile north of Fernando, representing the "granitic wash land" at the foot of the hills; the other from lowland near the old Mission two miles west of Fernando.

San Gabriel Valley. This valley lies east of Los Angeles and reaches from the mountains southward to the alluvial plains. It is watered by the San Gabriel River and bordered on the east by the Puente Hills. and San Antonio débris cone. Its soil is a sandy loam. A column of

soil was taken by F. E. Johnson from the neighborhood of Covina and "represents an average of all of the different soil types." Another column was taken by Johnson from near Monrovia, and represents the heavier type of soil, the greater part of which is sandy and gravelly wash from the hills.

San Bernardino Valley. The eastern portion of the valley of Southern California, known as the San Bernardino Valley, is separated from the western by a range of low hills and by the débris cone of the San Antonio Creek, which issues from its valley just above Pomona and supplies most of the water to Chino Creek, which empties into the Santa Ana River. In the past, from time to time portions of the San Antonio flow has been diverted into the San Gabriel.

The valley covers a large area and comprises a large variety of soil types, a few of which are represented by soil columns. The valley slopes toward the south to the Rincon Basin and Santa Ana River, and is bordered by a rim of mesa on the north, east, and south.

The Valley Plains. The soils are chiefly of a sandy nature, of excellent depth and good fertility. The lowlands are sometimes highly charged with alkali that has been brought in by drainage from the higher valley. Several types of soil from the plains are represented in the columns.

Sandy loam soils of the central part of the valley are shown in a column from the former University of California Experiment Station tract, three miles southwest of Ontario, taken by J. W. Mills.

Highly sandy soils, apparently accumulated by wind storms blowing in from the mountain passes on the north, lie in the central part of the valley and are extensively planted in grapevines, the roots of which penetrate downward for very many feet. A column of this type of soil was secured at Guasti from the land of the Italian Vineyard Company.. Alluvial plains of the Santa Ana River, known as the Victoria Tract, a few miles east of San Bernardino.

The soils of the valley plain are all quite sandy and contain but small amounts of humus and of nitrogen. The tendency to crust over and to form a sandy hardpan or plowsole near the surface is quite usual with these soils. A succession of good green-manure crops grown, turned under deeply, and allowed to humify properly would add much to the value and fertility of these lands.

Low Lands. Near the border of Chino Creek there are low-lying lands forming a wide border of "moist lands" which do not need irrigation. Ten acres of these near Chino formerly formed a part of the Experiment Station of Southern California. A column from this was

taken by F. E. Johnson. Another column was taken near Pomona from a marsh spot known as a "cienega." This is a "limited area showing growth of water-loving plants, appearing sporadically in otherwise. arid surroundings-usually hillsides or valley margins-and occasionally giving rise to flowing springs." (Rept. Cal. Expt. Sta., 18921894, page 185.)

Mesa Lands. The mesa lands that border the valley are largely of a reddish loam type, interspersed on the north side by deposits of sand and gravel from the hillsides.

The red mesa extends eastward up the Gorgonio Pass to its summit at Banning, where it forms quite a high plateau above Timoteo canyon.

A column of the sandy mesa of the north side was taken in the western part of Highlands to a depth of twelve feet, in which the sandy soil continued to the bottom.

A column representing the red clay mesa was taken near Redlands by F. E. Johnson. The upper five feet were of reddish, sandy loam nature, below which there is a change to a sandy clay and finally to a gritty stratum.

A column from Riverside was taken from Arlington Heights orchard lands on the south, and we were able to reach a depth of eighteen feet with comparative ease.

Another mesa soil column was taken by F. E. Johnson from nearly one mile south of the town of Corona, and is a good representative of the orchard land of that vicinity. A depth of twelve feet was reached. with difficulty because of the presence of much gravel.

Los Angeles Alluvial Plain. The three rivers, Los Angeles, San Gabriel and Santa Ana, have each brought down from the San Bernardino Mountains large quantities of silt, sand and clay, and formed a large body or region of alluvial lands, known as the Los Angeles Alluvial Plains. Each river preserves its own course through these plains, and has built up its own alluvial plain with its own material independently of the others. We thus find that the soils of the San Gabriel are of a more sandy nature than those of the Santa Ana, probably because of the greater velocity of the river current over a shorter distance. The Santa Ana leaves the mountains east of San Bernardino and flows by a circuitous route along the southern side of the valley and thus has left most of its coarse material behind and deposited chiefly clays and silts in the alluvial plain.

The San Gabriel Plain is represented by three columns. One was taken from the place of Doctor Twombly, south of Fullerton, to a depth of ten feet; another from the place of J. B. Neff, near Anaheim: while the third column was taken a mile south of Compton.