CONSIDER THE SOIL 
5 
ADOBE 
Adobe soil, being composed largely of alluvial or playa clay 
(accumulations by deposit on broad, level spots in arid or desert 
regions) and silt with some sand, the requirements for clay soil 
apply to this type also with the additional caution that though 
high in potential productivity, it needs careful handling. Irriga¬ 
tion has been found to be the best method of supplying moisture 
where sufficient quantities of humus and sand have been added 
to release the fertility within this very fine textured type of soil. 
The extreme compactness of its particles renders it very sticky 
when wet and hard enough when dry to be used as material for 
constructing buildings. 
Sifted coal ashes or wood ashes, together with straw and manure 
—sand, humus and sawdust—will render an adobe soil perfect in 
texture for garden loam, which texture may be maintained large¬ 
ly by deep tillage, good drainage and adequate moisture. 
A. Desert Soil is extremely rich in plant food and is more or 
less alkaline (generally lying on clay subsoils). It demands humus 
and irrigation to release its valuable content. By tillage or deep 
mulches the necessary moisture is conserved to make this vast semi- 
arid plains country yield its wealth in productivity. 
B. Rolling Plains Soil is similar to the desert soil in character, 
yet differs in that its fine sandy or clay loams are more friable 
and are deeper and darker in color. Both respond to tillage and the 
addition of humus and sufficient moisture during the plant’s grow¬ 
ing season. A distinct group of plants thrive in these regions. 
C. The Edwards Plateau contains little tillable soil because it 
is shallow, stoney land, yet the soil, where of sufficient depth to 
sustain vegetation is mostly dark and calcareous, resting on lime¬ 
See Tiny 
Arrowheads 
on Soil Map 
(West Texas, 
Western 
Oklahoma 
and Eastern 
New 
Mexico) 
See Crosses 
on Soil Map 
See 
Combination 
of Symbols 
on the Soil 
Map 
stone. 
D. Western New Mexico contains soil similar in character to 
Eastern Arizona — largely 
alkaline, adobe sands, while 
the mountainous regions dif¬ 
fer but slightly in soil-texture, 
