First Principles of Soil FertilityOrange Judd, 1908 - 265 páginas |
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Página 17
... solid material of the plant should be formed from this gas , but it is well known that green plants have the power to decompose this gas , retaining the carbon and setting free the oxygen . This process is known as the " fixation ...
... solid material of the plant should be formed from this gas , but it is well known that green plants have the power to decompose this gas , retaining the carbon and setting free the oxygen . This process is known as the " fixation ...
Página 35
... solid mass but consists of small particles , or " grains , " with air spaces between , these spaces in the surface foot amounting to fully half the bulk of the soil . These grains vary in size ac- cording to the character of the soil ...
... solid mass but consists of small particles , or " grains , " with air spaces between , these spaces in the surface foot amounting to fully half the bulk of the soil . These grains vary in size ac- cording to the character of the soil ...
Página 36
Alfred Vivian. It was once thought that plants actually took in the very small solid particles of soil , and that the purpose of cultivation is to render the particles minute enough for the plant to absorb . It is now known that no food ...
Alfred Vivian. It was once thought that plants actually took in the very small solid particles of soil , and that the purpose of cultivation is to render the particles minute enough for the plant to absorb . It is now known that no food ...
Página 40
... solid particles of the soil . It has been shown that seven of these ele- ments are essential to plant growth . Experience has proved that only three of these elements ( i . e . nitrogen , phosphoric acid and potash ) are likely to ...
... solid particles of the soil . It has been shown that seven of these ele- ments are essential to plant growth . Experience has proved that only three of these elements ( i . e . nitrogen , phosphoric acid and potash ) are likely to ...
Página 48
... solid rock into more or less fertile soils , by a series of changes much like those to be described . The Rocks Must be Pulverized . - Evidently the first step toward the conversion of the solid rock into soil must have been the act of ...
... solid rock into more or less fertile soils , by a series of changes much like those to be described . The Rocks Must be Pulverized . - Evidently the first step toward the conversion of the solid rock into soil must have been the act of ...
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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.