Part 5 (2/2)
Sulphuric acid 0.3 ”
Silica 0.5 ”
Chlorine 0.3 ”
This a.n.a.lysis shows very accurately what a given weight of asparagus abstracts from the soil, but it does not, and can not, show or even indicate certain indispensable demands. In this, as in other cases, the a.n.a.lysis of a crop is a very uncertain guide to its proper fertilization. It should be clearly understood by every cultivator of the soil that no rigidly fixed formulas can be given for any one crop on all soils. The question of quant.i.ty of application and of proportion must always, in the very nature of the case, remain more or less a matter of individual experiment. The following formula, given by Prof.
P. H. Rolfs, makes a good asparagus fertilizer:
Nitrogen 4 per cent.
Potash 5 ”
Available phosphoric acid 7 ”
One thousand five hundred pounds of the above formula should be applied per acre. When possible apply twenty to forty tons of vegetable material, such as partially rotted rakings of barnyard manure. Where such vegetable matter is procurable, the quant.i.ty of nitrogen may be decreased proportionately. If manure is obtainable, allowance should be made for the fertilizing elements contained therein.
An excellent formula for one ton of asparagus fertilizer, given by Prof.
W. F. Ma.s.sey, consists of:
200 lbs. nitrate of soda 700 ” cottonseed-meal 800 ” acid phosphate (13 per cent.) 300 ” muriate of potash
This will yield 4.9 per cent. ammonia, 6.1 per cent. available phosphoric acid, 8.4 per cent. potash.
The effects of the application of a scientifically balanced fertilizer ration upon asparagus is clearly ill.u.s.trated in Fig. 21, which presents a photographic reproduction of an experimental plat of the North Carolina State Horticultural Society at Southern Pines, N. C., fertilized with
250 lbs. nitrate of soda 400 ” acid phosphate 160 ” muriate of potash
per acre, while Fig. 22 shows a plat of equal size which remained unfertilized.
[Ill.u.s.tration: 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 quant.i.ty of each element:
_Element_ _Pounds of different materials for one acre_ { 800 to 1,000 lbs. cottonseed-meal; or Nitrogen { 350 to 400 ” nitrate of soda; or { 275 to 300 ” sulphate of ammonia; or { 400 to 600 ” dried blood.
{ 300 to 500 lbs. kainit; or Potash { 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.
[Ill.u.s.tration: FIG. 22--NORTH CAROLINA EXPERIMENT FARM ASPARAGUS PLOT; UNFERTILIZED]
”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 quant.i.ty 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 quant.i.ty of plant food unused and left over in the soil.”
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 quant.i.ties of stable manure per acre, as recommended by some successful growers. As already stated, formerly it was thought necessary to place large quant.i.ties 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.
The plan of top-dressing beds during the fall or early winter is gradually giving way to the more rational mode of top-dressing in the spring or summer. It was believed that autumn dressing strengthened the roots and enabled them to throw up stronger shoots during the following spring. This is a mistake, however. In the Oyster Bay region formerly all manuring was done in the spring, but the practice of applying all fertilizers immediately after the cutting is finished is rapidly increasing. The reason for this is found in the fact that, during the growth of the stalks, after the cutting season is over, the crowns form the buds from which the spears of next season spring, and it is probable that it is princ.i.p.ally during this period that the roots a.s.similate and store up the materials which produce these spears. This being true, the plant food added to the soil and becoming available after the cessation of vegetation in the autumn can have little, if any, effect upon the spears which are cut for market the following spring; it first becomes of use to the plant after the crop has been cut and the stalks allowed to grow. Thus the manuring of the autumn of 1901 will not benefit the grower materially until the spring of 1903.
Nevertheless, some highly successful asparagus raisers continue to apply fertilizers in the spring, as evidenced by the following directions given by one of the most prominent growers in the Oyster Bay district.
”After the roots have been set in the drill, put enough soil on them to cover about two inches. Then sow about 500 pounds of high grade potato fertilizer per acre in the drill. As the weeds commence to grow, cultivate and hoe, letting the soil cave down in the drill. About the middle of the season sow about 500 pounds more of fertilizer in the drill. Continue to cultivate and hoe the remainder of the season. At the end of the season the drill should be entirely filled up. The second year sow about 2,000 pounds of fertilizer per acre broadcast, plow the ground and harrow it down level, and keep the ground clean. The third year open the drill over the asparagus with a one-horse plow, broadcast 2,000 pounds of fertilizer per acre about the time the shoots begin to show, and back-furrow it up with a plow over the drill to form a ridge.
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