Again; third--the melioration of the physical qualities of a soil, the amendment of its dryness and excessive porosity, by means of peat, may be more effective for agricultural purposes, than the application of tenfold as much fertilizing, _i. e._ plant-feeding materials; in the same way that the mere draining of an over-moist soil often makes it more productive than the heaviest manuring.
2.--_On the characters of Peat that are detrimental, or that may sometimes need correction before it is agriculturally useful._
We have laid much stress on the amending qualities of peat, when applied to dry and leachy soils, which by its use are rendered more retentive of moisture and manure. These properties, which it would seem, are just adapted to renovate very light land, under certain circumstances, may become disadvantageous on heavier soils. On clays no application is needed to retain moisture. They are already too wet as a general thing.
Peat, when put into the soil, lasts much longer than stubble, or green crops plowed in, or than long manure. If buried too deeply, or put into a heavy soil, especially if in large quantity, it does not decay, but remains wet, and tends to make a bog of the field itself.
For soils that are rather heavy, it is therefore best to compost the peat with some rapidly fermenting manure. We thus get a compound which is quicker than muck, and slower than stable manure, etc., and is therefore better adapted to the wants of the soil than either of these would be alone.
Here it will be seen that much depends on the character of the peat itself. If light and spongy, and easily dried, it may be used alone with advantage on loamy soils, whereas if dense, and coherent, it would most likely be a poor amendment on a soil which has much tendency to become compact, and therefore does not readily free itself from excess of water.
But even a clay soil, if _thorough-drained and deeply plowed_, may be wonderfully improved by even a heavy dressing of muck, as then, the water being let off, the muck can exert no detrimental action; but operates as effectually to loosen a too heavy soil, as in case of sand, it makes an over-porous soil compact or retentive. A clay may be made friable, if well drained, by incorporating with it any substance as lime, sand, long manure or muck, which interposing between the clayey particles, prevents their adhering together.