MULCHED-BASIN SYSTEM OF IRRIGATED CITRUS CULTURE. 



11 



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 receive* I Lei 

 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 feel, 

 before and after irrigation, in the Vivienda grove, California, in ]'.)/',. 



[Note.— Minus signs indicate that the moisture content was reduced below the wilting coefficient.] 





Before irrigation. 



After irrigation. 



Soil treatment. 



CO 

 CM 



a 



Ha 



CO 



>> 

 "3 



Cji 



ti 

 3 



P. 



CD 



m 



O 



o 

 co 



o 



■ O 



CD 

 M 



cS 



CD 

 > 

 < 



CD 

 CS 



Hj 



CO 

 CM 

 CO 



a 

 5 



CO 

 CN 



>> 



CO 

 CM 



ti 



D 

 < 



CO 



CD 



a 



O 



Manure: 



Surface disked 



Same, plus lime . . 

 Trenched 



3.3 

 3.6 

 2.5 

 4.1 

 4.3 



4.1 

 4.2 

 4.5 



1.8 



.4 



1.5 



.5 

 3.4 

 2.9 



2.7 

 3.0 

 2.2 

 4.1 

 3.4 



2.4 

 2.8 

 4.3 



.4 

 -2.4 



2.7 



.2 



2.4 



1.9 



1.9 

 2.5 

 -2.1 

 3.3 

 3.4 



-2.0 

 2.4 

 4.0 



1.1 



- .7 



0) 



C 1 ) 



.7 



- .3 



2.4 

 1.1 

 1.1 

 2.9 

 4.0 



-2.4 

 2.1 

 4.1 



G) 



0) 



C 1 ) 



(») 



(') 



2.9 



2.4 



(') 

 1.6 

 4.1 



1.4 

 3.0 



.8 

 3.9 



2.6 

 2.6 

 .9 

 3.1 

 3.4 



.5 

 2.3 

 4.2 



1.1 



- .9 



2.1 

 .4 



1.6 

 .9 



6.7 

 5.4 

 7.4 

 7.2 



8.2 

 6.1 



6.9 



4.8 



6.4 

 5.4 

 7.1 



5.7 



8.7 

 8.8 

 6.1 

 7.2 



8.4 



9.0 

 6.2 

 7.5 



8.1 

 7.2 



8.5 

 7.5 

 9.1 

 8.3 



9.0 

 7.6 

 1.4 

 6.5 

 6.9 



3.4 

 6.0 

 6.7 



9.7 

 8.2 



0) 



(') 

 8.8 

 7.1 



4.9 

 2.7 

 - .6 

 6.6 

 8.5 



-2.0 



5.8 

 7.5 



C 1 ) 



0) 



(») 



(') 



C 1 ) 

 6.8 

 7.8 



(') 

 6.0 

 7.5 



7.2 



Same, plus lime.. 

 Alfalfa: 



7.9 





7 7 



Same, plus lime.. 

 Sweet clover: 



Cover crop 



Same, plus lime . . 

 Barley: 



Cover crop 



Same, plus lime . . 

 Disk cultivated 



6.4 































- .3 



- .8 







3.0 

 2.7 



0) 

 0) 





i 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 

 after 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. 



