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Each of these has its special advantage and disadvantage, and 
under certain conditions will do better than any of the others. 
MANURING. 
The use of stable manure, organic waste products as also con- 
centrated organic manures is not alone beneficial from a stand- 
point of increasing the fertility of a soil, but it also improves 
its mechanical and physical condition, to say nothing of the valu- 
able services rendered through the presence of favorable bacteria 
usually found in these products. The waterholding power, the 
permeability and the temperature of the soil are favorably affected 
by these organic manures. Soils are often dead or sterile owing 
to the lack of humus, although a chemical analysis may show the 
presence of sufficient plant food for any number of crops. A 
suitable treatment with organic manure will render these fertile. 
When mixed with chemical fertilizers organic manures are steril- 
ized more or less, whereby their favorable bacterial action on the 
soil is practically destroyed. Wherever possible they should be 
used alone, therefore. 
CORRECTION OF ACIDITY OR ATTCALINITY. 
Good arable soils should be neutral in their chemical reaction, 
or nearly so, to be fertile ; a more or less pronounced acidity or 
alkalinity is harmful to plant-life. To correct such unfavorable 
conditions the underlying causes must first of all be ascertained , 
before deciding on the proper remedy. Most acids, with perhaps 
the exception of carbonic acid, are injurious to plant-life. Lime 
in one form or other is the usual antidote against soil acidity ; 
others are wood ashes, carbonate of potash, etc. Neutralizing an 
alkaline soil depends chiefly on the nature of the alkali present. 
Superphosphate is often a good remedy, but frequently special 
treatment with acid material is necessary to overcome the causes 
of sterility. 
GENERAL. 
The inoculation of soils with nitrifying bacteria is of great 
value in the improvement of soils, likew^ise the use of carbon 
bisulfide. 
