 | William Laxton - 1865 - 484 Seiten
...with it. The proper proportion of the various earths might vary from 50 to 70 per cent, of liliceoui matter, 20 to 40 per cent, of clay, and 10 to 20 per cent. of calcareoui matter. The earth would bear a constant succession of crops of the same kind, if the mineral... | |
 | 1865 - 794 Seiten
...improve the soil by mixture with it. The proper proportion of the various earths might vary from 60 to 70 per cent, of silicious matter, 20 to 40 per...clay, and 10 to 20 per cent, of calcareous matter. The earth would bear a constant succession of crops of the same kind, if the mineral ingredients removed... | |
 | David Page - 1874 - 376 Seiten
...not too much so : and, in case of need, the subsoil should be able to improve the soil by admixture with it. The proper proportion of the various earths...climate is wet or dry, the soil should be friable or porous, or adhesive and retentive, and the best soil is that which, in long drought, is never very... | |
 | joseph rogerson - 1840 - 500 Seiten
...inches, the constituent parts of a soil "ill then require to be from 50 to 70 per cent, of sand, 20 to 30 per cent, of clay, and 10 to 20 per cent, of calcareous matter. It will, however, be fouad that a very small proportion of the soils of Great Britain are naturally... | |
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... matter. The earth would bear a constant succession of crops of the same kind, if the mineral ingredients removed by one crop were supplied in the same state from year to year. But this could only be done as the result of a nice calculation, and by... 