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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 manures, 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:
Data relative to the best 7 of the 145 competing erops.
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.
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, N. Y. 7 E. P. Kellenberger, Madison Sandy loam...... No fertilizer at all.
«Prize 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 7 of the 45 competing crops—Continued.
Variety of seed.
Statistics of harvested crops.
Cobs. Kelis: Cobs. Ker: Green. cured.ically
Crib Chem- Water
...do .............. 3.0x38.0 | 1,821 4 White Gourd ...... 4.0x 12.0 1,393 5 Large White ......... 5.5 x 48.0 | 1,826 6 King Philip .......... 3.5 x 3.0 1,776 7 Eclipse variety early 6.0x30.0 | 1,497
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
green weight, although larger in their dry weight, after what would ordinarily be called very heavy manuring. These facts are quite in accord with the general results of work at experimental farms, which, according to the South Carolina department of agriculture, have shown that increasing the amounts of the fertilizers beyond a certain point gives no corresponding increase in the amount of grain, and but few of the applications pay for their cost. There is abundant experimental proof that for any given soil there is a limit to the amount of profitable manuring. The process of improving the soil, like the process of fattening cattle, is comparatively gradual and requires time. The margin of profit in the application of manures is narrower than is generally supposed. It is equally important to attend to the selection of the seed, the thorough cultivation, and the natural fertilization that results from the cultivation of the Leguminosa and the rotation of crops.
PART II.-EXPERIENCE IN OPEN AIR OR NATURAL CLIMATE.
STUDIES IN PHENOLOGY. Under the general heading we shall consider, first, the wild plants and their natural habits; second, the plants cultivated at experiment stations under instructive experimental conditions, and, third, the statistics of each and the experience of farmers in general from a practical point of view. The study of the forest or natural habits of plants leads us into the phenology of plant life.
Phenology is a term first applied by Ch. Morren to that branch of science which studies the periodic phenomena in the vegetable and animal world in so far as they depend upon the climate of any locality. Among the prominent students of this subject, one of the most minute observers was Karl Fritsch, of Austria, who in his Instructions (1859) gives some account of the literature of similar works up to that date. He distinguishes the following epochs in the lives of plants, and especially recommends the observation of perennial or forest trees that have remained undisturbed for at least several years. His epochs are:
(1) The first flower.
As Fritsch considers that the development of the plant so far as its vegetative process is concerned depends principally upon temperature and moisture, but that its reproductive process depends principally upon the influence of direct sunlight, therefore he adds a sixth epoch for trees and shrubs—viz:
(6) The first unfolding of the leaf or the leaf bud or frondescence.
This is the epoch when by the swelling of the buds a bright zone is recognized which opens out and the green leaf issues forth. Corresponding with the formation of the leaf is its ripening and fall from the tree, which Fritsch adds to his list of epochs, viz:
(7) The fall of the leaf or the time when the tree has shed fully one-half of its leaves; as the wind and heavy rains accelerate this process the date is liable to considerable uncertainty independent of the vitality of the plant. Therefore, in this, as in all other epochs, Fritsch, in endeavoring to lay the foundations of the study, rejected those cases in which any unusual phenomenon, such as wind or drought or insects, had a decided influence on the observed dates.
Many plants blossom a second time in the autumn, although they may not ripen their fruits; therefore in special cases Fritsch adds an eighth epoch, viz:
(8) The second date of flowering. Of course it is understood that if the second flowering is brought about artificially, as by irrigation, pruning, or mowing, that fact must be mentioned.
When the flowers blossom in clusters, such that the individuals are lost sight of in the general effect, then, in addition to the first flower, we note the following item:
(9) The general flowering or the time when the flowers are most uniformly distributed over the plant.
For 118 varieties Fritsch gives in detail the phenomena that characterize the date of the ripening of the fruit. He also gives an equally elaborate system of observations on birds, mammals, fishes, reptiles, and insects, and especially the mollusks or garden snails and slugs. THE RELATION OF TEMPERATURE AND SUNSHINE TO THE DEVELOPMENT OF PLANTS—THERMOMETRIC AND ACTINOMETRIC CONSTANTS.
Reaumur was the first to make an exact comparison of the different quantities of heat required to bring a plant up to the given stage of maturity, and since then many authors have written on this subject.
I will here give a brief summary of views that have been held by . prominent authorities as to the proper method of ascertaining and stating the relation between temperature and the development of plants.
Reaumur (1735) adopted simply the sum of the mean daily temperatures of the air as recorded by a thermometer in the shade and counting from any given phenological epoch to any other epoch. He employed the average of the daily maximum and minimum as a sufficiently close approximation to the average daily temperatures, and evidently in the absence of hourly observations any of the recognized combinations of observations may be used for this purpose. Reaumur found from his observations that the sum of these daily temperatures was approximately constant for the period of development of any plant from year to year; hence this constant sum is called a thermal constant in phenology. For the three growing