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crops, or rye, oats, or field peas should be sown to help hold the 
surface. Little by little, but more rapidly than would be expected 
from the forbidding aspect of the field, the land can be reclaimed 
again and made productive through the accumulation of humus and 
organic matter. A soil containing a fair quantity of humus will 
wash less readily than one nearly destitute of this matter. 
A soil containing a fair supply cf lime is much less liable to 
wash than one similarly situated and exposed which is deficient in 
lime. The reason of this is that clays whi^h are deficient in lime, 
when once brought into suspension by moving waters, will remain 
in suspension and keep the water turbid fora long time. Clays 
which are heavily impregnated with lime salts, on the other hand, 
are in a flocculated state, the fine grains of clay being held together 
and in contact with the larger grains of sand. I bis flocculated 
mass quickly settles and is originally not so easily disturbed and 
carried off by moving water. A field treated with an abundance 
of lime is thus Jess easily washed by heavy rains. 1 he results of 
investigations by Schulze, Schloesing, and Hilgard have shown in 
a most emphatic way the beneficial changes which take place, 
especially in stiff clav soils, by the application of lime. 
The change in the physical condition of the soil which is pro- 
duced by the lime, and which is likewise produced by a number of 
other chemicals ordinarily used in commercial fertilizers, is another 
important factor worthy of consideration. A stiff day soil is 
practically impervious to the penetration of surface water when it 
is delivered in such torrents as we are liable to have in our summer 
storms. A well-limed soil, on the contrary, although it may con- 
tain as much clay but in which the particles are flocculated or 
drawn together, is much more pervious to water, and the amount 
of water whidrthe soil will carry down through underdrainage is 
increased, and the excess which has to flow off over the surface is 
diminished. The surface washing of cultivated fields, especially 
those which are naturally deficient in lime, can be greatly dimin- 
ished, therefore, by the free application of this substance to them. 
A number of the ordinary fertilizing materials have an important 
effect upon the texture of soils and upon the permeability of soils 
to water, but few systematic investigations have been carried on 
in this line and not much, except of local importance, has been 
definitely settled by experiments or by the experiences of farmers. 
Washing of lands may be prevented by methods of 
CULTIVATION AND UNDERDRAINAGE. 
The depth and character of the tillage are very important factors, 
in the washing of lands. A field in a condition ol fine tilth and 
ploughed to a depth of ten inches will hold two inches of rain fall 
and absorb it very readily, and a soil in such a condition will suffer 
no surface washing from any ordinary rainfall. Where it is possi- 
ble, therefore, land which is liable to wash should have the soil 
gradually deepened and be kept in a line slate ol tilth so as to ijv* 
