soils — FERTILIZERS. 1053 



was next studied, also for Iigowo oats, with the result thai a marked increase in 

 yields was obtained with ammonium sulphate. 



The next highest results were secured in the case of fertilization with ammonium 

 sulphate and sodium nitrate, while sodium nitrate alone with bone meal gave the 

 lowest results, this effect being equally marked both in the yield of total crop and of 

 grain. Liquid manure or albumen with sodium uitrate gave somewhat lower 

 results than sodium nitrate and ammonium sulphate. The effect of the phosphatic 

 fertilizers applied is, therefore, shown to depend to a large extent on the character 

 of the nitrogenous fertilizers applied or present in the soil. 



Culture trials with nitrogenous and phosphatic fertilization in increasing amounts. — 

 These trials were planned to study t he met hods of pot experimentation. They were 

 conducted in glass cylinders, 29 cm. deep by 24 cm. in diameter, filled with 28j kg. 

 of a sandy soil, low in nitrogen (0.011 per cent) and phosphoric acid (0.04 percent 

 phosphoric acid soluble in hot hydrochloric acid, sp.gr. 1.15), the crop groM n being 

 oats. 



In the first series, in addition to a basic fertilization of fine-ground marble', super- 

 phosphate, and potassium sulphate, with a slight addition of magnesium sulphate 

 and salt, sodium nitrate was added to different cylinders in amounts ranging from L.5 

 to6gm. per cylinder (50 to 200 kg. per hectare). Increasing nitrogenous fertiliza- 

 tions in all cases produced an increase in the crops harvested, the increase being 

 largest with the smallest amounts of nit rate applied and smallest with the heaviest 

 applications, so that the increase obtained beyond applications of L50 kg. per hectare 

 | 134 lhs. per acre ) may be considered w it hi n the limits of experimental error. 



Both the weights of kernels and of straw increased with increasing applications of 

 nitrate. The ratio of straw to kernels was narrowest in the case of the largest 

 amounts applied, up to 125 kg. per hectare, when a small widening of the ratio 

 began to appear. It was found, in general, that a fertilization of 150 kg. per hectare 

 (=0.026 gm. per kilogram of soil) produced an optimum development of the crop, 

 and that the crop produced on a fertilization of 50 Ult. of nitrate by its appearance 

 gave decided evidence of a lack of proper nitrogenous fertilization. 



In the second series the trials were conducted under similar conditions as in the 

 case of the preceding series; 0.71 to 5.71 gm. of superphosphate (corresponding to 25 

 to 200 kg. per hectare) were added to sets of :; cylinders each. The increase in the 

 oat crop harvested from the different cylinders was less regular in this than in the 

 preceding series. The highest increase was obtained between 25 and 50 kg. ; between 

 75 and 125 kg. only a small increase in yield was secured, while at 150 kg. a marked 

 increase again occurred, the maximum crop being obtained at 175 kg. Between 175 

 and 200 kg. a decrease in yield occurred. The optimum results evidently lay between 

 75 and 15() kg., and maybe placed at 0.017 gm. per kilogram of soil for the soil exper- 

 imented with and under the conditions of these trials. — p. w. WOLL. 



On the factors which influence the fertilizing- value of the phosphoric acid 

 of bone meal, II. (t. Sodkrb.wm (Landw. Vers. Stat., 68 (1905), No. •>'-/, pp. 847- 

 ,.'''>.'). — Experiments in glass cylinders 50 cm. high and 25 cm. in diameter carried 

 out with oats during 1002 and 1903 are reported. (See also the preceding abstract. ) 

 They included comparative tests of superphosphate, dicalcium phosphate; tricalcium 

 phosphate, Thomas slag, Algerian phosphate, apatite, and hone meal alone or com- 

 bined in various ways w ith sodium nitrate, ammonium nitrate, ammonium sulphate, 

 and other nitrogenous fertilizers | BOme organic), the object of the combination being 

 to determine the influence of the different nitrogen compounds on the availability of 

 the phosphoric acid of the phosphates, as has also been done by Prianiahnikov 

 (E. S. R., 17, p. 



The results show that the bone meal in presence of ammonium salts, as well as of 

 organic nitrogen compounds, gave larger yields than when used in connection with 



