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floating in the air and were deposited in the pots in which the plants
grew. As a rule, the greater the abundance of tubercles the more
vigorous were the plants and the greater the gain in nitrogen. The
gain of nitrogen from the air by the legumes explains why they act as
renovating crops. (Agr. Sci., Vol. IV, p. 22.)

From some careful experiments by A. Petermann on yellow lupins
(Lupinus luteus) the author concludes that the physiological rôle of
the tubercles must not be exaggerated. They can not be the only
cause of the fixation of nitrogen, although their presence may explain
why the intervention of atmospheric nitrogen is most marked in the
case of the Leguminose. He further shows that sodium nitrate is not
injurious, but beneficial, to lupins. The trouble in its use results
mostly from the fact that it is very soluble and is soon washed down
by the rain out of the reach of the roots, which must then draw their
nitrogen from the atmosphere by means of the microbic organisms.
(Agr. Sci., Vol. IV, p. 264.)

Pagnoul has measured the loss and gain of nitrogen by the soil as the result of the cultivation of special crops. He sowed grass and clover in four pots, but left two others without any crop. The gain of nitrogen permanently fixed in the soil in one year—March, 1888, to March, 1889—was as follows: With no crop the soil gained at the rate of 29 kilograms per hectare per year, with the grass crop 394 kilograms, and with the clover crop 904 kilograms. On the other hand, the total proportion of nitrogen removed from the soil by the drainage water was in each case as follows: No crop, 85; grass, 5; clover, 18. (Agr. Sci., Vol. IV, p. 325.)

2667--05 M-11

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Chapter IX.

RELATIONS OF CROPS TO MANURES, FERTILIZERS, AND

ROTATION

The preceding section having shown how easily all the valuable nitrates are dissolved and washed away by rain and how completely the permanent fertility of a field depends upon microbic action within the soil, and especially when attached to leguminous plants, we shall therefore not be surprised to learn that expensive and artificial chemical fertilizers and guanos are often less important than the enrichment that comes more naturally by the rotation of crops.

ARTIFICIAL FERTILIZERS AND MANURES.

As the result of twelve years' experience, J. W. Sanborn, of Missouri, states that although both science and practice assert the efficacy of artificial fertilizers, yet their profitable use is a matter of grave concern both in the granite soil of New England and in the richer soil of the Mississippi Valley. His general conclusions are that we do not need to use as much nitrogen in this climate as in Europe, especially as in England, nor as much as has generally been considered necessary; that enriching by rotation of crops is the preferable method; that nitrogen (viz, fertilizers) may be profitably bought only for a few winter or early and narrow-leaved plants, but, as a general truth, broad-leaved plants and those maturing in late summer and in the fall do not require addition of nitrogen to the soil. (Agr. Sci., Vol. I. p. 227.)

From the extensive experiments with fertilizers made at the Ohio Agricultural Experiment Station the following results have been secured, based on both station work and that done by cooperating farmers throughout the State:

Maize.On soils capable of producing 50 bushels of shelled corn to the acre no artificial fertilizer is likely to produce an increase of crop sufficient to pay the cost. On soils deficient in fertility, phosphoric acid may be used with profit.

Wheat.-As a rule no more wheat has been harvested from plats treated with commercial fertilizers than from those receiving no fertilizers, whereas farm manures produced a marked increase. At the present prices of grain and fertilizers the increase of crops will not cover the cost of the fertilizer.

Oats.-Plats receiving nitrates showed a marked superiority in the growing season, but lodged badly before harvest. Muriate of potash gave an insignificant increase. (Agr. Sci., Vol. IV, p. 237.)

(162)

E. F. Ladd, of the Agriculture Experiment Station at Geneva, N. Y., urges the necessity of a more thorough and systematic study of climate and soil (Agr. Sci., Vol. IV., p. 36) in order that we may better understand the great diversity and contradictions in the experimental field work, so called. Thus one year's experiments at the same station and with all possible care will show that the “Welcome” oats are vastly more productive than the “ White Russian," and the very next year reverses this decision. In the same year a neighboring experiment station operating on the same varieties arrives at opposite conclusions. In 1887 the observations showed that fertilizers did not affect the chemical composition of the grasses, but in 1888 the influence was very marked. Ladd finds that the contradictions in the reports of oat crops for 1885 and 1886 at the Ohio and New York stations are apparently due to considering only such factors as monthly rainfall and temperatures. He urges that the soil temperatures, sunshine, wind, the humidity in the soil, and the aeration of the soil are equally important factors. Any season will give some sort of a crop, but the maximum crop must depend upon the fertilizer and the relation of the fertilizer to the season. Thus Warington has shown that a dry and warm season is most favorable for the action of nitrate of soda, while a moderately wet season is most favorable for the action of sulphate of ammonia. The reason of this appears to be that plants are unable to appropriate to their use the sulphate of ammonia until the salt has become nitrified, and this phenomenon of nitrification does not take place except under the influence of a certain amount of moisture in the soil. A soil that conserves its moisture for a considerable time and is properly cultivated to permit the free permeation of the air gives the best results with sulphate of ammonia, but does not necessarily give the best results with the nitrate of soda, since this is so soluble as to be soon drained away out of reach of the plants. Thus in different seasons, with different fertilizers, we have the crops of wheat shown in the following table:

Hectoliters per hectare.

Nitrate of soda and a wet season (1882).
Nitrate of soda and a dry warm season (1887)
Sulphate of ammonia, wet season (1882).
Sulphate of ammonia, warm dry season (1887)

23. 45 31.57 28.86 23. 56

Again, crops, like animals, have a certain limit to their capabilities; if the maximum yield is 50 bushels per acre, then it is a waste to put on more fertilizer than needed to attain this limit. Evidently, therefore, we have to study the relation of the climate to the fertilizers and the soil in order to ascertain a very important item in the relation between climates and crops.

Many specific results as to the relation between climates and crops on a large scale are entirely altered from season to season by the chemical influence of the climate on the fertilizer and the soil in general. We have here, therefore, a source of discrepancy that has contributed appreciably to obscure the influence of the climate on the plant.

PRIZE CROPS.

Evidently crops of seed or grain depend, primarily, on the amount of nitrogen in the sap, and, secondarily, on the elaboration of those precious nitrates into albuminoids. Hence the recognized need of inanures, fertilizers, and leguminous crops. But the study of the remarkable crops of corn raised as so-called prize crops in 1889 demonstrates that excellent results may be obtained on some soils without manures, and is otherwise very instructive, since the heavy manuring in many cases must have been largely counteracted by the waste caused by rain. I condense the following from the monthly reports of the department of agriculture of South Carolina for March, 1890, pp. 233–243 :

In 1889 the American Agriculturist offered a prize of $500 for the largest crop of corn that should be grown on 1 measured acre of ground during the year 1889. Forty-five leading competitors appeared, of whom 10 were from South Carolina. The average of these 10 prize crops from that State gave 105 bushels per acre, whereas the average of the 25 crops from other States was 103.5 bushels per acre. The accompanying table gives most of the more appropriate statistics for the 7 best results in this list of 45 :

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Data relative to the best ry of the 45 competing crops.

Serial
No.

Locality.

Soil.

Quantity of fertilizer.

1 Z. J. Drake, Marlboro County, Poor sandy soil..

(a) S.C. 2 Alfred Rose, Yates County, Sandy loam. 800 pounds Mapes corn manure.

N. Y. 3 George Gartner, Pawnee Rich black loam. 90 loads barnyard manure.

County, Nebr. 4 J. Snelling, Barnwell County, Sandy loam. 300 bushels stable manure; 300 bushS. C.

els cotton seed. 5 L. Peck, Rockdale County, Ga.. do

4 loads stable manure; 30 bushels

heated cotton seed; 1,000 pounds Packard standard fertilizer; 500

pounds cotton-seed meal. 6 B. Gedney, Westchester Clay loam

800 pounds Mapes corn manure. County, Ñ. Y. 7 E. P. Kellenberger, Madison Sandy loam.... No fertilizer at all.

County, Ill.

aPrize crop No. 1.—The sandy soil had been fertilized in 1887 by Mr. Drake and had yielded in 1888 the great crop of 917 pounds to the acre of lint cotton, and was therefore already profiting by the heavy enrichment that is had received that year. In February, 1889, in preparation for the present contest, Mr. Drake began a new course of manuring, and from that date until June 11 the following material was added to the soil : One thousand bushels stable manure; 867 pounds of German kainit; 867 pounds of cotton-seed meal ;. 200 pounds of acid phosphate; 1,066 pounds of manipulated guano; 200 pounds of animal bone; 400 pounds nitrate of soda ; 600 bushels of whole cotton seed. The total cost of this manure was $220 and the work in applying it, together with the frequent culture that was given, made the whole expense of the crop $264. The value of the corn that was raised was $206, and the value of the manure left in the soil for the next year's crop was at least $150.

Data relative to the best ry of the 45 competing cropsContinued.

Statistics of harvested crops.

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Average Green weight. Dry weight. Bushels of kernels.
distance
of hill.

Chem-Water
Ker-

Ker-
Cobs.

Crib
Cobs.

Green.
nels.

ically nels.

cured.

dry.

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Ft. In. 1 Gourd variety of 4.0x 6.0 | 3,133 14,273 2,726 12,132 southern

white Dent improved by 20 years of careful selection on his

plantation. 2 Early Mastodon. 3.0x12.0 | 4, 134 11,764 2,954 9,764 3 ..do

3.0x36.0 1,821 9,559 1,174 7,647 4 White Gourd

4.0x12.0 1,393 7,316 1,212 6,218 5 Large White

5.5X48.0 | 1,826 7,305 1,367 | 6,136 6 King Philip

3.5 X 3.0 1,776 6,683 | 1,154 5,717 7 Eclipse variety early 6.0x30.0 1,497 7,311 617 5,349

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174 137 111 110 102

15 18

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yellow Dent.

With regard to the weather and other items during this season of 1889 at these seven stations I have found only the following notes referring to the prize crop No. 1:

Cultivation. The seed was planted March 2, 5 or 6 kernels to each foot of a row; the plants began to sprout on the 16th; there was a good stand the 25th, and the stalks were thinned out to 1 every 5 or 6 inches on April 8; no hilling was done, but the whole acre was kept perfectly level. The crop was harvested November 25.

Weather.-In March the weather was warm and land moist. Good rains on March 3, 10, and 15; rain on 24th; 1 inch of rain on May 26; 6 inches of rain May 30; rain on June 4 and 5; rain on June 9. The season in general was rainy and wet as compared with other years; rains following frequently, and no irrigation was necessary.

The record of largest corn crop up to this date had been that of Doctor Parker, Columbia, S. C., in 1857, who raised 200 bushels to the acre.

The exact measures of all these 45 competing crops have been made the basis of a comparison showing that on the average of the 17 eastern crops the percentage of nitrogenous matter was 10.78, but for 14 southern crops it was 10.33, and for 14 western crops 10.26, showing an imperceptible difference slightly in favor of the eastern climate and soil and seeds.

In respect to the general advantage of fertilizers, and notwithstanding the apparent advantages gained by some of the heavy manuring in these competing crops, attention is called to the fact that competitor No. 7 raised a very fine crop of 130 bushels green or 95 dry bushels to the acre without any fertilizer whatever, and that the crops reported by Nos. 4, 5, and 6 were even less than his in their

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