Magnesia (MgO), 4.69 percent
Iron oxid (Fe_{2}O_{3}), 1.18 "
Phosphoric acid (P_{2}O_{5}), 17.33 "
Sulfuric acid (SO_{3}), 6.49 "
Silicic acid (SiO_{2}), 2.13 "
Chlorin, 3.11 "
This analysis was made upon the so-called pure ash, deprived of its unburned carbon, and freed of sand and carbon dioxid.
Effect of fertilization on the yield and starch content: Experience in Germany has shown not only that liberal fertilization with nitrogen is favorable to the production of a large crop of potatoes, but also that this is accomplished without decreasing the percentage of starch therein. The following table shows the increase in yield, percentage of starch, and amount of starch obtained by nitrogen fertilization, the results being expressed in hectares[1] and kilograms:
Effect of Nitrogen Fertilization on Yield and Starch Content of Potatoes.
++-
| Without Nitrogen. | With Nitrogen.
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| | Yield of | Yield of | | Yield of | Yield of
Variety of Potato. | Starch. | tubers per | starch per | Starch. | tubers per | starch per
| | hectare. | hectare. | | hectare. | hectare.
++++++-
| Percent. | Kilograms. | Kilograms. | Percent. | Kilograms. | Kilograms.
++++++-
Seed, | 18.01 | 20,900 | 3,780 | 18.17 | 24,870 | 4,507
Champion, | 21.33 | 19,510 | 4,152 | 21.48 | 24,470 | 5,233
Imperator, | 19.00 | 22,560 | 4,235 | 18.70 | 26,830 | 5,007
Magnum Bonum, | 18.41 | 19,170 | 3,522 | 18.07 | 22,510 | 4,057
Aurelie, | 19.47 | 18,950 | 3,653 | 19.75 | 23,550 | 4,609
Reichskanzler, | 22.78 | 14,300 | 3,236 | 22.61 | 17,250 | 3,875
Juno, | 19.33 | 17,590 | 3,422 | 19.92 | 20,900 | 4,199
Amaranth, | 22.47 | 16,180 | 3,619 | 22.84 | 18,310 | 4,188
Charlotte, | 19.42 | 17,041 | 3,305 | 19.67 | 20,774 | 4,081
Gelbfleischige Zwiebel, | 19.97 | 19,888 | 3,946 | 19.91 | 21,772 | 4,323
Dabersche, | 21.82 | 17,377 | 3,778 | 21.80 | 20,313 | 4,399
Weissfleischige Zwiebel, | 20.51 | 16,877 | 3,442 | 20.58 | 19,501 | 3,936
Schneerose, | 18.84 | 19,653 | 3,724 | 18.66 | 22,343 | 4,186
Nassengrunder, | 19.08 | 19,701 | 3,725 | 22.12 | 21,889 | 4,813
Gelbe Rose, | 21.09 | 16,847 | 3,547 | 20.60 | 20,177 | 4,129
Hortensie, | 17.72 | 22,416 | 3,907 | 17.45 | 26,381 | 4,532
Richter's Lange Weisse, | 19.37 | 22,134 | 4,267 | 19.19 | 24,490 | 4,664
Rosalie | 18.27 | 19,866 | 3,557 | 18.25 | 22,186 | 4,003
Achilles, | 21.02 | 18,886 | 3,962 | 20.93 | 20,913 | 4,376
Alcohol, | 16.47 | 16,270 | 2,673 | 16.31 | 20,339 | 3,327
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Average, | 19.77 | 18,806 | 3,673 | 19.85 | 21,998 | 4,332
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It is evident from the data given in the table that the liberal application of nitrogenous fertilizers increases the yield per acre of tubers and of starch to a very marked extent, although the average percentage of starch present is increased very little. Converting the average data given in the foregoing table into their equivalents in pounds per acre, we have the following
- ↑ 1 hectare = 2.471 acres. 1 kilogram = 2.205 pounds.
