MULCHED-BASIN SYSTEM OF IRRIGATED CITRUS CULTURE. Il11 
vation with a surface application of manure disked in appeared to 
be slightly more effective than cultivation without manure. The 
lower moisture content of the soil where lime was added is attribu- 
table to the fact that the lime was used on the lower ends of the rows 
and also to the fact that the slope of the land was slightly greater 
at the lower end of the tract, so that the lime treatments received less 
water. Incidentally, this brings out another important advantage of 
the basin system, namely, that all trees may be given the same 
amount of water regardless of the physiography of the grove. 
TABLE III.—Average percentages of available soil moisture to a depth of 3 feet, 
before and after irrigation, in the Vivienda grove, California, in 1915. 
[NotTE.—Minus signs indicate that the moisture content was reduced below the wilting coefficient.] 
Before irrigation. After irrigation. 
Soil treatment. Pe <S Bs =F = S S 3 S 33 33 6 = 
g b oh 1S : 5 S = ba ob = 
le We ee On Olea (ee ars. es ae ie 
Manure: 
Surface disked....| 3.3] 2.7} 1.9] 2.4] @) |...--. PRS NOE eel GEO EO @) Veaces 
Same-plusiimoncli S16) 1a:0l2)5)| letein(t) leeks YG || BEN EES POG OR Oy. escee 
Trenched.......-- Dis | GeO) EO aL (Oyo goeee TOS Cah Gok PASO BSS SN) (ah) loos 
In basins.....--.-. A GE Ue Bee AED Ir BRO eee eek abl BAA emda Ge Grell Sa Gell GES = 0674 
Same, pluslime..| 4.3) 3.4] 3.4] 4.0] 2.4] 3.0] 3.4 ]..--... SEAs|G1659) (ae Saxon lee Sala 
Alfalfa: 
Trenched.....---- ALT | RAED) EOL A) ne Bl G2 OO SEE OXON). Wesco 
Tn basins........- AQ 2E8 e254, |) > 255 Ae 6 SO PRB ash GO GOA aay) GEO) 26 7 
Same, plus lime..} 4.5] 4.3] 4.0] 4.1] 4.1] 3.9] 4.2 ]...... Uo \y Cet! teil etem lO, 4 
Sweet clover: 
Cover crop......-- 1.8 A eA lo Eyre pra seers | ies Tah | GRO SBT Re Oe seecellocouc 
Sain, ES Me Ate A hess Gy iat a 25 LOPE VED BER OAN@) elle ceaaclloneas 
Barley: 
Cover crop......-. Pe oDee (a CE) ear |e ers sete | cess QIU ORs saree || x (Lat eter el nese eller 
Same, pluslime..| .5 eT ANAC) had ees actiel eee pial Seeree ori Oe leat cal ee Rei 0( 0) nal eel one alla 
Disk cultivated....... 3.4] 2.4 (|= 1h @) eee -ee UGG | eegoal ie 4s eee Sa BBO CD) Weesce 
Same, plus lime...... 259) |e els9) |—s 53) |e Sa@)r aemeeee SO tbe || hei | arte Bar Ir (CO Wee So 
1 Basined. 
BASIN AND COVER-CROP EXPERIMENTS IN THE VICTORIA 
GROVE. 
Another series of experiments was also begun in the spring of 
1915 on the Victoria tract, near Riverside, Cal., the soil being a red- 
clay loam with granite rock 3 to 4 feet below the surface. The upper 
layer of this granite to the depth of a few inches is sufficiently de- 
composed to be removed with a soil tube, but below this the rock is 
very hard. 
The treatments in this grove, which were practically the same as 
those just discussed for the Vivienda grove, are given in the first 
column in Table IV,1 which shows the average moisture content to 
a depth of 3 feet. The moisture available for growth before and 
aiter each irrigation is shown in Table V. 
1 The check row given in Table IV was not cultivated, and conditions were such that 
another row for a cultivation test was not available. 
