TY  - BOOK
TI  - Soil: the yearbook of agriculture 
U1  - 630.5 20
PY  - 1957///
CY  - Washington, DC
PB  - U.S Government
KW  - Soil
N1  - CONTENTS

Principles
the basis of fertility
what soils are
physical properties
growth of plants
e.tc

Fertility
plant nutrition and soil fertility
nitrogen and soil fertility
soil phosphorous and fertility
e.tc

Practices
how to determine nutrient needs
soil reaction and liming
trends of fertilizers
materials and mixtures
e.tc

Soil care
principles of tillage
saline and alkali soils
erosion on cultivated land
e.tc

Moisture
conserving soil moisture
irrigation in arid regions
e.tc

Systems
cropping systems and soil
the use of soil maps
three farming systems
e.tc

Regions
Special uses
; Includes index
ER  -