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sened, or prevented, if a half of this quantity of nitrogen is supplied by castor pomace and the other half by nitrate of soda?
d. What are the comparative effects on quality and quantity of leaf of applications of equal quantities of potash in the following forms: Cottonhull ashes, high grade sulphate of
a'.ash, the same with lime, double sulphate of potash and magnesia, the same with lime, pure carbonate of potash, and pure nitrate of potash?
e. Is it possible to absolutely prevent " pole burn" and to cure the crop perfectly on the stalk, by the use, in very damp, "muggy" weather, of artificial heat simply as a means of ventilating and partly drying the air of the barns?
The 1896 crop completed the experiments, which have been directed by E. II. Jenkins, vice director of the station. The interest in this work, the most exhaustive of the kind ever attempted, is so great that we have compiled a careful summary of the results. This appears in the annexed table, which is based on the average of the first four crops produced. The quantity of the different fertilizing materials applied per acre each year varied slightly, but averaged for the four years as stated in the table. The same is true of the actual plant food contained in these mixtures. The idea was to supply the same quantity of potash to each plot, but in different form. This was also true of phosphoric acid, but both the amount and form of nitrogen varied considerably. The season of '92 was favorable, and a large yield of fine quality was obtained; the next three seasons were comparatively dry. The crops, therefore, varied considerably in yield and quality, but the average for the four years partly removes these seasonal influences, and enables us to judge more clearly of the effect of the fertilizers.
The larger the amount of nitrogen used, the heavier was the crop and the larger the per cent of wrappers. (See Plots D, H, I, J.) There were no very marked differences in yield due to the form in which the nitrogen was applied,—castor pomace, G, shows a slight advantage over cottonseed meal, D, but when (J) all the nitrate of soda was applied between the rows, at first cultivation, the yield of wrappers averaged 132 pounds per acre more than Plot I, similarly fed, except that half of the nitrate was applied at the first and the balance at second cultivating. This fact is directly contrary to theory, and is not due to the absence of sufficient moisture after the second application to dissolve the nitrate so that the plants could feed upon it, because the same result was noted during the first dry season and the succeeding wet years.
Linseed meal gave quite as good results in yield and quality as cottonseed meal. Indeed, the more moderate application per acre, on Plot F, of linseed meal, with less than half as much cottonhull ashes as some of the other plots, and a little bone meal, produced one of the most profitable crops, because cost of fertilizer was smaller than on other plots. In view of results on F, it is a question whether so much as 340 pounds per acre of actual potash is at all necessary.
The form of potash used seems to have as much effect as the quantity. The carbonate of potash gave distinctly unfavorable results compared with sulphate, which is now used for tobacco by all scientific farmers. The poorest yield of all was on P, dressed with double carbonate of potash and magnesia. Yet tobacco on this soil evidently needed magnesia, for on K and L, where potash was put on in the form of double manure salt (consisting of sulphate of potash united with sulphate of magnesia), the yield was considerably better than where only high-grade sulphate of potash was concerned.
With these crops of cigar wrapper leaf, quality was what determined their market value. It depends upon color, texture, thinness, lightness, freedom from spots, holes, coarse ribs or other imperfections, burning quality, and other even more delicate points. It is not possible to intelligently average these points in the four years' crops from each plot. But the average number of wrappers required to weigh a pound is important, as the thinner the leaf the more cigars it will cover and—* other qualities being equal—the more it is worth. The McKinley bill imposed a duty of $2 per pound on wrappers "of which more than 100 are required to weigh a pound." The length of time a cigar will hold its fire is also important. Hence, the comparative capacity of holding fire was ascertained by careful tests of each crop; the leaf which held fire the shortest time in each of the four crops was called 100, and the table gives the average of these determinations, the larger figures indicating the longer capacity to hold fire; the figures under the heading "Cured" are the average of fire tests made of the 1892-3-4 crops, when pole cured, or barn cured, while under "Fer." are given average results of similar tests of each of these crops after fermentation. After each crop had "gone through the sweat," or fermentation, judgment as to the quality for wrappers of the leaves from each plot was finally passed by practical experts, the best crop each year being marked 1, the second best 2, and so on, and this data is given in the last three columns of the following table. For conven