Volume weight of certain field soils
1928
Harland, M.B. | Smith, R.S.
A maximum variation in weight of about 2.75 million pounds in 40 acre-inches is shown in the soil types studied. Both the upper and lower extremes are silty soils. Very sandy, light-colored soils might increase the range, and peaty soils undoubtedly would do so. In dark-colored silty soils, the A, B, and C horizons show progressively greater weight with increase in depth through 40 inches examined. Sandy soils and light-colored soils in the same region as the dark-colored ones show a decidedly greater weight as a result of their coarser texture and decreased organic content. There seems to be no marked difference in volume weight between silty and clayey soil sections. Mature soils seem to be heavier than younger soils. This greater weight probably is due in part to lower organic content, and to the presence of "ashy" horizons which have a high volume weight. The B horizons, especially if relatively impervious, and the C horizons, for no reason which is apparent, show the same trend. There is more variation in weight between types in the older light-colored soils than in the younger dark-colored ones. Deeper horizons tend to be heavier than shallower ones, whether fine or coarse textured, in both the light and dark-colored soils. Clayey horizons are seemingly no lighter in weight than silty horizons, and possibly are heavier. Sandy horizons are probably heavier than finer-textured ones, though the data are not conclusive on this point.
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