. Productive soils; the fundamentals of successful soil management and profitable crop production. Soils. 68 CROPS AS FEEDERS must give up one hundred eighteen pounds of nitrogen, seven- teen pounds of phosphorus, ninety-two pounds of potassium and pounds of calcium. In case of a fifteen-ton cabbage crop, at least eleven tons of material are left on the field. Thus a fifteen-ton cabbage crop requires for its production approximately one hundred eighty pounds of nitrogen, sixteen pounds of phosphorus, one hun- dred twenty-five pounds of potas- sium and sixty- two pounds of calcium. In case
. Productive soils; the fundamentals of successful soil management and profitable crop production. Soils. 68 CROPS AS FEEDERS must give up one hundred eighteen pounds of nitrogen, seven- teen pounds of phosphorus, ninety-two pounds of potassium and pounds of calcium. In case of a fifteen-ton cabbage crop, at least eleven tons of material are left on the field. Thus a fifteen-ton cabbage crop requires for its production approximately one hundred eighty pounds of nitrogen, sixteen pounds of phosphorus, one hun- dred twenty-five pounds of potas- sium and sixty- two pounds of calcium. In case of hemp, it would seem that a soil needs to give up only small amounts of the elements to pro- duce a good crop, and that it ought to grow well on poor soils. On the contrary, it re- quires a fertile soil to grow a good crop of hemp. Root Systems of Crops Differ.— Fig 26 —Root-hairs are the absorbing portion of plant SomO plants have roots These root-hairs comemto mtimate contact with the soil ^vxr+A-nai-vrA anrJ \x^c^}^ A, root-hairs of mustard plants, with soil adhering and with soil tJA teilfei V t; tAllU wtill removed B, root-hairs of wheat, when very young, and four Hp-irAlnn^rl rnn-/- qa?-- weeks later (After Sachs ) ueveiopeu TOOT, sy stems enabling them to draw plant-food elements and water, particularly, from large volumes of soil (Figs. 26 and 27). Corn and alfalfa are typical examples. Such crops as onions, cabbage and beets have much less extensive root systems. It is the nature of some plants to develop fibrous and much branching roots largely in the tilled portion of the ground—^these are commonly called shallow rooted plants. Farm Plants are Interesting Subjects for Study.—In the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Weir, Wilbert Walter, 1882-. Philadelphia London, J. B. L
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectsoils, bookyear1920
