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WALLACE H. FULLER
e. Marshy Soils. Marshy soils are located in low basins and accumulate
peaty-marshy material, organic matter, and salt plus organic residues.
/. Anciently Irrigated Sierozem-Meadow Soils. They are as the name
implies—irrigated ancient oases within the sierozem zone. They have
formed from silt-suspended irrigation water and added organic fertilizers.
The cultural deposition ranges from 1 to 2 meters. Soil profile differentiation is lacking and texture throughout is uniform. Carbonates have not
accumulated appreciably.
g. Solonchaks. Solonchaks are salty soils. They appear in deep depressions, lowlands, on denuded plateaus, and on outcrops of salt-bearing rocks
within the sierozem zone. Large areas stretch along the shores of the Caspian and Aral Seas.
h. Solonetses. The Solonetses can reach a maximum profile development
and morphological structure in which sodium exercises its full effect. Some
leached Solonchak soils are found interspersed in this class. They occupy
only a small total acreage and occur in small, local spots only.
The Turkestan Desert has fairly deep soils compared with most deserts.
Only a limited area is stony and gravelly. Salt-affected soils appear mostly
in the Takyrs, Solonchaks, irrigated oases, river deltas, and Caspian coastal
plains.
H. CENTRAL ASIA—TAKLA-MAKAN
The Takla-Makan Desert lies between the Turkestan Desert on the west
and the Gobi on the east. The Thar is to the south. Its elevation is between
700 and 1400 meters and is characterized by hot summers, cold winters,
and extreme aridity. Several rivers flow into it from the Tien and Kunlan
Mountains, which are important sources of water for irrigated agriculture
concentrated along their flood plains. The Dzungaria Desert of North
Sinkiang lies to the north of the Takla-Makan. Several smaller deserts occupy areas within the Takla-Makan but their soil characteristics are not
sufficiently different to discuss them separately in this very limited review.
Oases on the desert margins have produced grains for centuries but have
been shrinking in size from the onslaught of sand invasion (Academia
Sinica, Sand Control Team, 1962) as have the agronomic footslopes.
Thus the soil sequence seems to follow a pattern of sand and sand dunes
in the largest portion of the desert, the center, expanding outwards and
south, and saline soils in depressions on finer-textured material interspersed
between high dunes. Near the base of mountains, coarse alluvial gravel,
coarse sand, and stone (gobi) surfaces overlie limy skeletal soils. The texture of the soils becomes finer proceeding into the flatter and more arid
central sand region of the Takla-Makan. Sierozem soils are widespread
WALLACE H. FULLER
e. Marshy Soils. Marshy soils are located in low basins and accumulate
peaty-marshy material, organic matter, and salt plus organic residues.
/. Anciently Irrigated Sierozem-Meadow Soils. They are as the name
implies—irrigated ancient oases within the sierozem zone. They have
formed from silt-suspended irrigation water and added organic fertilizers.
The cultural deposition ranges from 1 to 2 meters. Soil profile differentiation is lacking and texture throughout is uniform. Carbonates have not
accumulated appreciably.
g. Solonchaks. Solonchaks are salty soils. They appear in deep depressions, lowlands, on denuded plateaus, and on outcrops of salt-bearing rocks
within the sierozem zone. Large areas stretch along the shores of the Caspian and Aral Seas.
h. Solonetses. The Solonetses can reach a maximum profile development
and morphological structure in which sodium exercises its full effect. Some
leached Solonchak soils are found interspersed in this class. They occupy
only a small total acreage and occur in small, local spots only.
The Turkestan Desert has fairly deep soils compared with most deserts.
Only a limited area is stony and gravelly. Salt-affected soils appear mostly
in the Takyrs, Solonchaks, irrigated oases, river deltas, and Caspian coastal
plains.
H. CENTRAL ASIA—TAKLA-MAKAN
The Takla-Makan Desert lies between the Turkestan Desert on the west
and the Gobi on the east. The Thar is to the south. Its elevation is between
700 and 1400 meters and is characterized by hot summers, cold winters,
and extreme aridity. Several rivers flow into it from the Tien and Kunlan
Mountains, which are important sources of water for irrigated agriculture
concentrated along their flood plains. The Dzungaria Desert of North
Sinkiang lies to the north of the Takla-Makan. Several smaller deserts occupy areas within the Takla-Makan but their soil characteristics are not
sufficiently different to discuss them separately in this very limited review.
Oases on the desert margins have produced grains for centuries but have
been shrinking in size from the onslaught of sand invasion (Academia
Sinica, Sand Control Team, 1962) as have the agronomic footslopes.
Thus the soil sequence seems to follow a pattern of sand and sand dunes
in the largest portion of the desert, the center, expanding outwards and
south, and saline soils in depressions on finer-textured material interspersed
between high dunes. Near the base of mountains, coarse alluvial gravel,
coarse sand, and stone (gobi) surfaces overlie limy skeletal soils. The texture of the soils becomes finer proceeding into the flatter and more arid
central sand region of the Takla-Makan. Sierozem soils are widespread