First Principles of Soil FertilityOrange Judd, 1908 - 265 páginas |
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Página 16
... obtained by irrigation even in sections of very heavy precipitation . While the amount of water that falls on the land can not be controlled , much can be done to save the water so as to tide over the periods of scanty rain- fall ; a ...
... obtained by irrigation even in sections of very heavy precipitation . While the amount of water that falls on the land can not be controlled , much can be done to save the water so as to tide over the periods of scanty rain- fall ; a ...
Página 17
... obtain their carbon in this manner but must procure it through the decom- position of organic matter , or in other words , must have their food previously prepared for them . Green plants , on the other hand , can manufacture their ...
... obtain their carbon in this manner but must procure it through the decom- position of organic matter , or in other words , must have their food previously prepared for them . Green plants , on the other hand , can manufacture their ...
Página 19
... proved that the supply of carbon in the air is ample for the largest crops . To ⚫be sure , in certain pot experiments a larger yield was obtained by increasing the carbonic acid in the air , ATMOSPHERE AS A SOURCE OF PLANT FOOD 19.
... proved that the supply of carbon in the air is ample for the largest crops . To ⚫be sure , in certain pot experiments a larger yield was obtained by increasing the carbonic acid in the air , ATMOSPHERE AS A SOURCE OF PLANT FOOD 19.
Página 20
Alfred Vivian. obtained by increasing the carbonic acid in the air , but under field conditions the yield is limited by other factors , and never by the supply of carbon . Carbon Costs the Farmer Nothing . The point of practical ...
Alfred Vivian. obtained by increasing the carbonic acid in the air , but under field conditions the yield is limited by other factors , and never by the supply of carbon . Carbon Costs the Farmer Nothing . The point of practical ...
Página 25
... obtained by Boussingault , and the question was con- sidered settled by most experimenters . About the same time field tests were conducted at Rothamsted which indicated that when clover and other leguminous plants were grown , there ...
... obtained by Boussingault , and the question was con- sidered settled by most experimenters . About the same time field tests were conducted at Rothamsted which indicated that when clover and other leguminous plants were grown , there ...
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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.