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acid and potash acre added agricultural amount animals applied average bacteria barnyard become bedding bone called carbon cent CHAPTER clover commercial fertilizers composition compounds condition constituents contains corn crop dependent desirable determine dry matter effect elements excrement experiments fact farm farmer feeding fertilizers field given gives grain ground growing grown growth hand humus important inches increase indicate ingredients kind known land larger leaching less lime liquid loss manure materials meal ments method mineral mixed moisture necessary nitrates nitrogen obtained organic matter oxygen phos phosphate phosphoric acid plant food plots plowed possible pounds practically present probably produced profit purchased quantities rains ration readily reason remains removed rock roots seen shown soil solid Station substances sufficient supply surface tillage tion valuable yield
Página 225 - Furthermore, the mineral elements are relatively cheap, while the nitrogen is relatively expensive, and the economical use of this expensive element, nitrogen, is dependent to a large degree upon the abundance of the mineral elements in the soil. It is, therefore, advocated that for all crops and for all soils that are in a good state of cultivation, a reasonable excess of phosphoric acid and potash...
Página 1 - ... woods ; All silent is the earth and sky, Except with his own lonely moods The blackbird holds a colloquy. Over the broad hill creeps a beam, Like hope that gilds a good man's brow, And now ascends the nostril-stream Of stalwart horses come to plough.
Página 245 - One will seek to know what the different forms of plant-food are, what they do, from what sources they can be obtained, and how he can use them to best advantage. He will become to some extent an investigator, and will, of necessity, take a deeper interest in his work.