This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
The analyses quoted by me in the Essay were given with a view to show the general principles on which the value of night soil depends. Much of the value of such materials will depend on the manner in which they are prepared. While barn-yard manure requires to be thoroughly fermented, before its fertilizing properties become available to the plants, night soil is immediately active.
If I understand the question raised by the last speaker, I do not disagree materially with him as to the propriety of manuring on the surface with long stable litter - that is, covering it a few inches. Such manure benefits heavy soils by its decomposition, but in the case of light soils this would be unnecessary. With proper management little loss need result from surface manuring. Manure which is fully decomposed, must lose some of its valuable elements which are already in a condition to be of immediate use to the roots of plants. By plowing in long manure in the fall, leaving it to decompose till spring, it will then be available. I can not see the sense of what is termed surface-manuring; that is, spreading it on the surface where it is fully exposed. True, the gases in part are absorbed by the soil, yet much of the volatile matter is lost and much washed down by the rains. These matters are, however, brought up again by capillary attraction. With reference to the dark liquid, resulting from peat or muck lands, that contains ulmic as well as apocrienic acids, and these are in a measure injurious to plants.
These may be neutralized by an alkali, or they may be corrected by treating with lime.
Dr. George P. Norms bad some experience in the application of manure; he had always thought it better to plow it in than spread it on the surface. One objection he saw in fall plowing of manure, that in the spring, when required by the plants, the best part was gone. The nearer the food was to the top, where the roots of the young plant are, the better. Top-dressing in fall and plowing in the spring, appeared to him the proper method with regard to the absolute propriety of this practice of surface-manuring; one thing was clear, that one or the other method was the right one, and we should not rest satisfied until this had been clearly ascertained.