It makes sandy soils more compact and therefore more powerful to hold water and plant food.
It makes heavy clay soils more open and porous, giving them greater power to absorb moisture and plant food. This admits also of better circulation of the air in the soil, and prevents baking in dry weather.
Farm manures influence all of the conditions necessary for root growth while the commercial fertilizers influence mainly the plant food conditions.
The farm manures are good for all soils and crops.
They are lasting in their effects on the soil.
BARN OR STABLE MANURE
Barn or stable manure consists of the solid and liquid excrement of any of the farm animals mixed with the straw or other materials used as bedding for the comfort of the animals and to absorb the liquid parts.
The liquid parts should be saved, as they contain more than half of the nitrogen and potash in the manure.
The value of barn manure for improving the soil conditions necessary for root growth depends in a measure upon the plant food in it, but chiefly upon the very large proportion of organic matter which it contains when it is applied to the soil.
These factors are influenced somewhat: by the kind of animal that produces the manure; by the kind of food the animal receives; by the kind and amount of litter or bedding used; but they depend particularly on the way the manure is cared for after it is produced.