. Elementary principles of agriculture; a text book for the common schools . large surface to the action of the root-hairs. Professor King has figured out the result:* ''Suppose we take a marble exactly one inch in diameter. It will just slip inside a cube one inch on a side, and will hold a film of water square inches in area. But reduce the marble to one-tenth of an inch and at least 1,000 of them will be required to fill the cubic inch, and their aggre- gate surface area will be square inches. If, however, the diameter of these spheres be reduced to one-hundredth of an inch, 1
. Elementary principles of agriculture; a text book for the common schools . large surface to the action of the root-hairs. Professor King has figured out the result:* ''Suppose we take a marble exactly one inch in diameter. It will just slip inside a cube one inch on a side, and will hold a film of water square inches in area. But reduce the marble to one-tenth of an inch and at least 1,000 of them will be required to fill the cubic inch, and their aggre- gate surface area will be square inches. If, however, the diameter of these spheres be reduced to one-hundredth of an inch, 1,000,000 of them will be required to fill a cubic inch and their total surface area will be square inches. Suppose, again, that the soil particles have a diameter of one-thousandth of an inch. It will then require 1,000,- 000,000 of them to com- pletely fill the cubic inch and their aggregate surface area must measure square ; All in one cubic inch of soil. When all the surfaces are moist, it is then Fig. so. a perfectly plain why a fine soil will withstand more drought and give more root-feeding surface than a coarse soil. 76. Root-Hairs Absorb Plant Food. Root-hairs absorb the water that covers the soil particles as thin films. *King, The Soil. 'A -J (I tilth.
Size: 2453px × 2038px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauth, bookcentury1900, bookdecade1900, booksubjectagriculture
