MULCHED-BASIN SYSTEM OF IRRIGATED CITRUS CULTURE. 27 
TABLE X.—Percentage of humus in the first and in the second 3 feet of soil in 
the Sunny Mountain grove, California, in 1915—Continued. 
Furrow system Furrow system 
Basins near upper | Basins near lower Av- | near upper end of | near lower end of | Ayvy- 
end of tract. end of tract. erag tract. tract. erage, 
Depth and ped both 
date. SOG inten serena nd Gl area ETN Paul meal CMS ends 
a aes re ae Su one cae mo of cere ees rs ms ce ras aes a of 
3828/8 p 8 |5 8 8/k 8) & & | tract.| 3 85 S| S| Sb 13 S/n 8/4 8) p & | tract 
Lal Cur Get [ort = Sy | aes ae) 
a im Mm i4 is m& wm is & im |< isa ie la | < 
Second 3 feet: 
Apr. 9...|0.07'0. 05/0. 05} 0. 06/0. 12/0. 05/0. 03) 0.07) 0.06,0.05/0. 02) Tr.| 0.02)0.07\0. 04/0.03) 0.05) 0.04 
Ballo 9 0 . 05) . 06] .03] .03) .04] .05) .05) .03/0.03} -04] .13) .08] .05) .08) .06 
July 10..| .07| .04) .04) .05) .07| .04] .04) .05) .05) . 06) 05) .04) .05) .13) .11) .05} .10) .07 
Aug.6...| .12) .05) .05| .07| .08] .06] .04; .06] .07) .07| .05) .04) .05) .18) .09) .08} .12) .08 
Sept. 21.| . 08} .03] .03/ .05) .11) .05} .03] .06} .05) . 06} .04) .03) .05} .09) .06) .06) .07, .06 
age..| .09) .04) .04)  .06) .09) .05) .03) .06) .06) .06) .04) .03; .04) .12) .08)| .05) .08 .06 
VIVIENDA GROVE. 
Determinations of the average percentage of humus in the first 
3 feet of soil in the Vivienda experimental tract are presented in 
Table XI. Samples taken in October, about four months after the 
mulch was apphed, showed an appreciable increase in the humus 
content of the soil in the basins. The mulch was carefully removed 
before sampling, so that only the soil itself was taken up. The 
percentage increase in humus was about the same in the basins 
mulched with manure and with alfalfa. 
The plat in which the barley was disked showed a marked increase 
in humus 50 days after the green cover crop was incorporated with 
the soil. The changes in humus content were all confined to the 
surface foot of soul. 
TaBLE XI.—Average percentage of soil humus to a depth of 3 feet when various 
treatments were given in the Vivienda grove, California, in 1915. 
Soil treatment. Sune 
Manure: 
Sumlacediskediysn cays Mun eye tii eae Nas eGR 
Same lus MME we eee ee eee aw ee eee 
TAMAS TTS hay ee a eh adhe eee a UO 
SQMTer ep LUSHAN: sey me ears geleinre Manon Pa os 
Alfalfa: 
Hn ROSSI See Ne feet Sse ee ease asec ocean LD al sere es 13 oll} 24 - 20 
Sar erp u SMM Oe seees ea pains nk ate anys cd ted seneuese 13 19 30 . 26 
Sweet clover: 
Disked in about August 15...........-.......2.... LAYS RSME ea 15 .13 Gare 
SHE OOVS) TOVMDESHIDUOI VS) ee se ogee She i ee Doers 3 21 23 (Di) |S 
Barley: 
Diskedeiny Illy pl Geese pesmi menue a Tue gee .16 ONG eskesess 25 (Cae omearsae 
Pasa: pluispliime ss We Me se even te eS ee .18 PI ees B25) (ese eee 
PDAS kere allay CO Ces ee seen ae EYE REE ee aati’ PGE Pe sees lll .19 Ce ae 
SATTTOe IU Splimte vee yas as ae oe nea eet), Wala ue Gat DP), Sass eee 16 19 Q) eral cee 
1 Basined. 
