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INDUSTRIAL A N D ENGINEERING CHEMISTRY
nitrate, cyanamide, calcium nitrate, and ammonium sulfate were efficient in the order given. Of the nitrogen applied there was recovered on the limed soils an average of 35 per cent from the sodium nitrate and ammonium sulfate, and 38 per cent from the calcium nitrate and cyanamide. The corresponding amounts on the unlimed soils were 32 and 31 per cent, respectively. With due allowance for inequalities of soil and errors in sampling and analysis, it still remains obvious that the synthetic nitrogen fertilizers gave as good average returns as the sodium nitrate and ammonium sulfate. I n pot experiments carried out in 1912,6 sodium nitrate gave an average recovery of about 52 per cent, ammonium nitrate about 42 per cent, and ammonium sulfate about 30 per cent. Experiments were carried out in 1915 and 1916' with ammonium phosphate made from cyanamide and sold under the commercial name of Ammo-phos. When used in the row for corn, 100-pound applications of Ammo-phos per acre did not depress germination, but slight injury appeared with 150-pound applications. The efficiency of the nitrogen in Ammo-phos was nearly as great as that in sodium nitrate. Later investigations with Ammo-phoss showed that in its effect on germination it is less toxic than nitrate of soda. In 1922 the question was raised with the New Jersey Station as to the agricultural value of urea made from cyanamide by treating the latter with sulfuric acid. It seemed particularly important to determine whether the small proportion of dicyanodiamide and of guanyl urea sulfate (dicyanodiamide in sulfate) found in the crude urea made by this process would depress plant growth. Hence a number of comparative germination and vegetation tests were made in that year with crude urea and several other nitrogenous fertilizers. The germination tests show that with nitrogen applications equivalent to 160 pounds of nitrate of soda per acre germination was not depressed by either pure or crude urea. With applications of nitrogen equivalent to 320 pounds of nitrate of soda per acre crude urea caused a retarded and lessened germination. The tests were made in a sandy loam soil. In a soil of finer texture the injury, under the same conditions, would have been less pronounced. Bacteriological studies carried on a t the same time showed that crude urea had a marked tendency to depress ammonia and nitrate formation in soils of different type. The same was true of commercial cyanamide, but not of chemically pure urea. Vegetation experiments were carried out in conjunction with the tests just described. A series of 38 pots each containing 12 pounds of white quartz sand was employed for the purpose. There were added in each pot 2 grams of acid phosphate, 1 gram of potassium sulfate, 0.25 gram of magnesium sulfate, 0.1 gram of ferric sulfate, and 4 grams of calcium carbonate. There were added, likewise. quantities of different nitrogen fertilizers equivalent, in each case, to 0.5 gram of sodium nitrate. The barley grown in these pots was reduced after germination to a uniform stand of six plants per pot. Information is given in Table I concerning the equivalent amounts of the different nitrogenous materials employed in the experiment. It was observed on January 19 that the barley seed planted 9 days earlier had produced a perfect stand except in Pots 25 and 26, which had received the double quantity of calcium cyanamide. On the whole, the average yields of dry matter, as recorded in Table I, show that the double portions of the nitrogenous materials gave larger returns than the corresponding single portions. Exceptions are noted in the case of cyanamide. Evidently the toxic substances in this material prevented the normal development of the plants. It may also be noted that the larger portion 6
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New Jersey Agr. Expt. Sta., RezX, 1912, p. 206. Allison, S o d Science, 6, 1 (1918). Coe. New Jersey Agr. Expt. Sta., Bull. 376.
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of the chemically pure urea did not produce such a large yield of dry matter as the smaller portion. This cannot be ascribed, however, to the presence of toxic substances. Otherwise, it is apparent that ammonium nitrate, calcium nitrate, and urea nitrate gave, on the average, as good results as sodium nitrate and ammonium sulfate. E x p e r i m e n t s Using Various Fertilizers in Quartz Sand ----GRAMS DRY MATTER-Increase over Pot TREATMENT Grams 1 2 Average check 1.10 1.5 1.3 1, 2 No nitrogen Sodium nitrate 8 . 3 5 8.25 0 . 5 ' 8.15 6:95 3, 4 8 . 7 5 10.06 1.00 9.40 8.10 5, 6 Sodium nitrate Ammonium sulfate 6.38 6 . 1 5 0.3735 6 . 6 0 5.08 7, 8 9, 10 Ammonium sulfate 0.7470 1 1 . 3 0 1 0 . 8 5 11.08 9.78 1 1 , 1 2 Dried blood 2.78 4.08 0.5860 5.00 3.15 13, 14 Dried blood 4.83 6.13 1.172 6.15 6.10 0.2260 15, 16 C. P. ammonium nitrate 6.20 7.50 6.50 8.50 0,4500 13.10 1 2 . 1 0 12.60 1 1 , 3 0 17, 18 C. P. ammonium nitrate 0.6647 1 9 , 2 0 Calcium nitrate 8.60 8.70 7.30 8,50 21,22 Calcium nitrate 1.3294 10.00 8 . 5 5 9.28 7.98 23, 24 Calcium cyanamide 0.95 0.3990 0.35 0.00 1.90 25, 26 Calcium cyanamide 0.13 0.7980 0.25 1.17 0.1698 8.10 27, 28 C. P. urea 8 .' 20 6.86 8.15 0.3376 6.58 6.30 29, 30 C. P. urea 5.28 6.85 0.2306 8.35 31, 32 C. P. urea nitrate 7.05 8.70 8.0 33, 34 C . P . urea nitrate 0.4612 12.8 11.96 1 2 . 3 8 1 1 . 0 8 0.1755 35, 36 Crude urea 5.45 5.08 4.70 3.78 37, 38 Crude urea 8.25 0.3510 6.83 8.13 8.00 T a b l e I-Vegetation
As has already been noted, toxic effects of fertilizers will vary with the texture and chemical make-up of soils, as well as with the methods of application. This may be well illustrated by an experiment in which soil instead of quartz sand was employed. Quantities of good sandy soil distributed in pots received additions of acid phosphate, potassium sulfate, and ground limestone a t the rate of 800, 400, and 1000 pounds per acre, respectively. There were also added different nitrogen fertilizers in amounts equivalent to 400 pounds of nitrate of soda per acre. Barley was grown in the soils so treated. The yields of dry matter secured are recorded in Table 11. E x p e r i m e n t s w i t h Various Fertilizers in Soil -GRAMS DRYMATTERIncrease over TREATMENT Gram 1 2 Averaae check 8.90 8.75 No nitrogen 8.60 0 . 3 i n 9.80 9.70 9.75 1:hO Sodium nitrate 8.95 0.20 9.10 8.80 0.2368 Ammonium sulfate 0.83 9.15 0.3714 10.00 9.58 Dried blood 1.53 0.2530 9 . 8 5 10.70 10.28 Calcium cyanamide 0.47 8.10 0.1115 8.45 8.25 Crude urea 1.95 0.1070 10.00 1 1 . 4 0 1 0 . 7 0 C . P. urea 0.85 9.60 9.20 0.1433 10.00 Urea nitrate
T a b l e 11-Vegetation
Pot 1, 2
,;
4 6 7, 8 9, 10 11, 12 13, 14 15, 16 a,
It is evident that in this experiment cyanamide caused no serious injury to the plants, but that crude urea depressed the growth somewhat. Urea nitrate and chemically pure urea gave results at least as good as those obtained with sodium nitrate and ammonium sulfate. These results are therefore in accord with others obtained a t the New Jersey Station.9 The assumption is thus justified that among the more concentrated synthetic nitrogen fertilizers urea is to be commended because of its high nitrogen content, its slight hygroscopicity, and its comparative safety. Urea made directly from ammonia and carbon dioxide is free from toxic substances. Urea made from cyanamide will contzin varying amounts of dicyanodiamide and guanyl urea sulfate. These may cause injury to crops when present in larger proportions. This type of urea, however, may be so made as to contain relatively small amounts of the objectionable ingredients. It should then be an effective nitrogen fertilizer. 0
McGuinn, Sod Sczence, 17, 487 (19241.
General Inorganic Compounds-The Department of Commerce announces that the total production during 1923, for sale, of aluminium and aluminium compounds, and of inorganic compounds not included in special chemical groups, was valued a t $137,721,152. This total represents an increase of 58.6 per cent as compared with 1921, and of 7.6 per cent as compared with 1919.
