dia ae ae Se ee Pie tac he SY, 
Kage Gee 
Contribution from the Bureau of Plant Industry 
2 WM. A. TAYLOR, Chief 
an Ryashin#ton. D. C. 
PROFESSIONAL PAPER 
UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 499 
- February 12, 1917 
THE MULCHED-BASIN SYSTEM OF IRRIGATED 
CITRUS CULTURE AND ITS BEARING ON 
THE CONTROL OF MOTTLE-LEAF 
By 
LYMAN J. BRIGGS, Biophysicist in Charge, C. A. JENSEN, Assistant 
in Plant Malnutrition Investigations, and J. W. McLANE, Lab- 
oratory Assistant, Office of Biophysical Investigations 
CONTENTS 
Introduction . . 2. ». 2. « » ee «© 
Cultural Practice in the Citrus Districts of 
California ... 
Plowsole ....... 
Organic Mulching . .... 
The Mulched Basin ... ra kh eine 
Moisture Determinations in the Sunny 
Mountain Grove ai auinan tts 
Soil-Moisture Measurements in Basins, 
under Cover Crops and under a Soil 
Mulch in the Vivienda Grove . .. . 
Basin and Cover-Crop Experiments in the 
Mictoria Grove .°.- ss ee 2 6 « « 
Furrow Irrigation Often not Adequate . 
Lateral Movement of Soil Moisture Very 
Slight .... anlovoreh kent eietenate 
Summer Cover Crops in Orange Groves 
not Practicable without an Increased 
Water'Supply’ 3.6000. 6 a se we 
e ° ® ° e e 
7. 2 © 
Page 
1 
D wm hm w 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1917 
Organic Mulches More Effective than Soil 
Mulchesin Conserving Water. ..« . 
Effect of Basining on Tree Growth. . . 
The Mulched Basin in Relation to Soil 
TEMPO ice! oie e Hapa tel autal  euee okiaite 
Effect of the Mulched Basins on Soil Con- 
ditions and Root Growth. . ... . 
Fruit Setting and Tree Growth as Influ- 
enced by the Mulching Material . . . 
Size of Basins . eer ore tau wire 
Cost of Preparing and Maintaining the 
Basins andthe Miulch . . 2. 2. + « 
Limitations of the Mulched-Basin System 
Humus Content of the Basins and the 
Check Soils; wa ss 0 0 ks ee 
Summary 
