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advantage AGRICULTURAL CHEMISTRY ammonia animal applied become body bone-earth bones bottle burns called carbonic acid carried clay collect common common salt compost consist contain corn crops draining drink dung elements employed especially exhibit exists experiment explain farm-yard farmer fermentation fertile fire give given glass gluten grass lands greater green grow heavy hydrogen illustrate important inorganic iron keep kind land large quantity leaves less light lime limestone liquid live magnesia manure marl matter meaning mixed naturally nitrogen oats obtain organic food oxide oxygen phosphoric acid piece plants ploughed potash potatoes pouring powder PRACTICAL principal produced profit proportion pupils quicklime raised referring require roots sand serve soda soil starch straw substances supply surface taper taste teacher thing turnip usually vegetable waste weight whole wood young
Página 17 - Q. Whence is the organic part of the soil derived? A. It is derived from the roots and stems of decayed plants, and from the dung and remains of animals and insects of various kinds. Q. Does this organic part form a large proportion of the soil ? A. Of peaty soils it forms sometimes three-fourths of the whole weight; but of rich and fertile soils it does not usually form more than from a twentieth to a tenth of the whole weight. Q. Can a soil bear good crops which does not contain a considerable...