As indicated in the previous paragraph, coarse manures should be plowed under, while those of fine texture will be most beneficial when used as a top dressing after plowing, especially upon heavy soils of moderate fertility. Surface applications after plowing certainly have a marked effect in improving physical conditions, in making soils warmer, more friable, and less subject to baking and washing.
A common practice in soils of rather low fertility is to use stable manures in hills or drills. This plan is seldom practiced by gardeners cultivating soils of high fertility, but it is without doubt an advantage in the thinner soils, because it secures greater concentration of plant food in the immediate region of the roots and results in a more economical use of the manure applied.
The spreading of stable manures on truck farms and on market gardens is generally done with an ordinary four-tine manure fork. This is the most economical method when the manure is spread from the wagon as hauled from livery stables. Manure spreaders, however, should be in more general use among commercial vegetable growers, because they save labor and secure a much more even distribution than is possible by hand spreading.