First Principles of Soil FertilityOrange Judd, 1908 - 265 páginas |
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Página 12
... surface of the bottle will be found to be covered with moisture . The earth around the plant should first be covered with a piece of oil cloth or oiled paper to make sure that the water does not come from the soil . If the underside of ...
... surface of the bottle will be found to be covered with moisture . The earth around the plant should first be covered with a piece of oil cloth or oiled paper to make sure that the water does not come from the soil . If the underside of ...
Página 19
... surface , and as only one - fourth of the earth's surface is land he estimated that the carbonic acid in the air is sufficient , without renewal , for a hundred years of growth . As a matter of fact , the supply of this gas is being ...
... surface , and as only one - fourth of the earth's surface is land he estimated that the carbonic acid in the air is sufficient , without renewal , for a hundred years of growth . As a matter of fact , the supply of this gas is being ...
Página 23
... surface soil . Some of these bacteria cause the fer- mentations and decay that return the carbonic acid to the air . Others , and these are of particular interest here , bring about the decomposition of the nitrogenous organic matter ...
... surface soil . Some of these bacteria cause the fer- mentations and decay that return the carbonic acid to the air . Others , and these are of particular interest here , bring about the decomposition of the nitrogenous organic matter ...
Página 25
... surface , but the explanation was never satisfactory . The conditions under which the pot tests were con- ducted were not normal , as the plants were grown in prepared soils that had been heated to kill any bacteria . they might contain ...
... surface , but the explanation was never satisfactory . The conditions under which the pot tests were con- ducted were not normal , as the plants were grown in prepared soils that had been heated to kill any bacteria . they might contain ...
Página 35
... surface foot amounting to fully half the bulk of the soil . These grains vary in size ac- cording to the character of the soil , being very fine in clay , and comparative- ly coarse in sandy soils . The roots of the plant push down ...
... surface foot amounting to fully half the bulk of the soil . These grains vary in size ac- cording to the character of the soil , being very fine in clay , and comparative- ly coarse in sandy soils . The roots of the plant push down ...
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Términos y frases comunes
acid and potash acre agricultural ammonia amount of nitrogen amount of plant animals applied average bacteria barn barnyard manure bedding carbonic acid clay clover commercial fertilizers complete fertilizers composition compounds condition corn crop decay deep stall denitrification drainage dry matter elements of plant Experiment Station fact farm farmer feeding fertilizing constituents fertilizing materials fertilizing value field grain green manuring ground grown hot fermentation humus important inches increase ingredients kainite land leaching legumes leguminous lime liquid excrement loss of nitrogen lysimeters manure produced materials ments method mineral matter mixed moisture necessary nitrate of soda nitrification nitrifying bacteria nitro nitrogen nure obtained organic matter oxygen phoric acid phos phosphate phosphoric acid plant food plant growth plots plowed pounds practically present rains ration removed rock roots rotation shown soil soil contains soluble substances sufficient sulphate superphosphate supply surface tillage tion urine wheat yield
Pasajes populares
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.