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Show Thorne and Thorne: Applications of Coal 81 Product A,...-JA commercial mixture composed largely of coal (patented) Product B,...-J A fertilizer containing coal sis 3-6-0) Product C,...-JA fertilizer containing coal sis 3-6-3) (guaranteed analy (guaranteed analy Product D,...-JA patented product extracted from coal tar, and claiming to have stimulative effects on plant growth. Results and Discussion Coal, being an organic material and containinq practically no available plant nutrients, must of course undergo some chemical changes in the soil if it is to be effective as a fertilizer. The ni trification tests conducted for a period of 12 weeks with the soil mixture maintained at room temperature and optimum moisture, indicate that both coal and roasted coal remained inactive In the soil (figure 1 ). Peat also caused no increase in the nitrate nitrogen but the three commercial products tested and the standard fer tilizer each induced some increase in nitrate nitrogen. In spite of the positive action of the commercial products in the nitrification test, all of them except the standard fertilizer were ineffective in increasing corn yields when applied at rates recommended by the manufacturer (tables 1 and 2). Coal, roasted coal, and peat had no influence on corn yields, while Product D, the patented "growth stimulant," actually decreased. yields, at the high fertility level. Appreciable increases in yields were obtained from the application of the 4-12-0 fertilizer. Thus, it is quite apparent that the products A, B, C, and D have no ferti lizer value nor growth promoting qualities under the conditions of this study. On the assumption that coal acts as a chemically inert ma terial in the soil and that any effects from coal are largely physical; coal applications were compared with applications of sand on Trenton fine sandy loam from near Lewiston, Utah, and on a heavy clay soil from the Dry Lake Valley. The coal used in this case and in the following experiment was obtained from a pile of slaked coal in the Price mining area where it is claimed that con siderable damage has been done by slaked coal deposited on the land by irrigation water. Results of the are comparisons given in tables 3 and 4. Yields of tomato plants were not materially decreased by additions of either coal or sand until applications were in equal proportion to the volume of soil. The decreased yields were most pronounced in the sandy loam soil, suggesting that they might have resulted from a "dilution" of the soil fertility. Applications of both sand and coal at rates of 5 and 10 tons per |
