68 
SOIL SURVEY OF BUFFALO COUNTY. 
be immediately tended to because all ditches on such soil are 
dangerous. 
Where the subsoil is clay and where clay or silt soil material 
is being brought down by the flood water, large gullies may be 
made to fill by putting in a dam of stumps, brush, and logs. 
Where the subsoil is sandy much greater care is required. If 
dams are built in the latter case, they need to be carefully con¬ 
structed to prevent the water from cutting around them. 
Dams of concrete, stone, wire mesh, and brush have been suc¬ 
cessfully used. Flume devices also have been used to carry the 
water over the head of the ditch and down into it preventing its 
continued growth. 
Planting willows and bushes on the sides and bottom of ditches 
too deep to fill often arrests the growth of the ditch. Sorghum, 
sweet clover, or rye make good emergency crops on eroded spots 
and fields which later need to be seeded to grasses and left in 
permanent sod. # 
♦See Bulletin 272 of the Wisconsin Experiment Station. 
