FIG. 21—NORTH CAROLINA'S EXPERIMENT FARM ASPARAGUS PLOT; FERTILIZED
The following table gives the amounts of different fertilizer materials necessary to give the desired quantity of each element:
| Element | Pounds of different materials for one acre |
|---|---|
| Nitrogen | 800 to 1,000 lbs. cottonseed-meal; or |
| 350 to 400 " nitrate of soda; or | |
| 275 to 300 " sulphate of ammonia; or | |
| 400 to 600 " dried blood. | |
| Potash | 300 to 500 lbs. kainit; or |
| 150 lbs. muriate of potash; or | |
| 150 to 300 lbs. sulphate of potash | |
| Phosphoric acid | 750 to 1,000 lbs. acid phosphate; or |
| 600 to 800 dissolved bone. |
"Asparagus requires very heavy manuring, and yet its composition would not indicate it," writes Mr. Charles V. Mapes. "The explanation is found in the fact that it must grow very rapidly, otherwise it is tough, stringy and flavorless, the same as with radishes. If it had a long season to grow in, like timothy hay, it might grow successfully in very poor soil. A half ton of timothy hay contains about as much plant food, and in similar proportions, as two thousand bunches of asparagus, or five thousand quarts of strawberries, and yet while this quantity of hay will grow on an acre of almost any poor soil, the strawberries or asparagus for a fair crop per acre require a rich garden soil. If the hay were obliged to make as rapid growth as the asparagus, then it also would require rich soil. With the strawberry there is but the lapse of a few weeks from the time of blossoming to the full development of its fruit. The plants need a superabundance of plant food within easy reach, otherwise the fruit is small and inferior. The plant can not bear profitable fruit and at the same time be compelled to struggle for existence. The same is the case with asparagus. Neither of these crops can take up out of the soil all the fertilizer that needs to be applied for their successful growth, and therefore there is necessarily a large quantity of plant food unused and left over in the soil."
FIG. 22—NORTH CAROLINA EXPERIMENT FARM ASPARAGUS PLOT; UNFERTILIZED
For these reasons, asparagus, while not necessarily an exhaustive crop, requires heavy manuring. One ton of high grade vegetable manure is none too much per acre, and is small, particularly in the expense, as compared with the larger quantities of stable manure per acre, as recommended by some successful growers. As already stated, formerly it was thought necessary to place large quantities of manure in the bottom of the deep trenches in which the young plants were set out, in order that sufficient fertility might be present for several years for the roots, as after the plants were once planted there would be no further opportunity to apply the manure in such an advantageous place. This theory has been found erroneous and the practice has been demonstrated to be rather a waste than otherwise, and besides the roots of asparagus thrive better when resting upon a more compact soil; nor is it necessary that the soil should contain great amounts of humus, or be in an extremely fertile condition when the plants are first put out, since by the system of top-dressing a moderately fertile soil soon becomes exceedingly rich and equal to the demands which the plants make upon it.