Table III. — Effect of Potassium Sulfate. 



Analyses. Per cent. 



Treatment. 



Check 

 K 



0.16 1.24 0.84 — 0.05 



The data show an increased sodium,* potassium and sulfur content, 

 with practically a constant percentage of nitrogen and phosphorus. 



A similar study of plants to which ammonium sulfate had been ap- 

 plied gave the results shown in Table IV. 



Plants to which sodium phosphate was applied showed a higher phos- 

 phorus content, 0,60% P2O5 and 1.17% P2O5 in a sample of 1915 in which 

 the calcium content was decreased (2.31 and 1.63% CaO, respectively, 

 in the last set of samples) ; the nitrogen content was increased by applica- 

 tions of sodium phosphate, the values 1.99%, 2.84% and 3.30% being 

 obtained from plants to which had been applied, respectively, none, 

 250 g. and 500 g. of sodium phosphate per 20 sq. ft. of bench space per 

 week for several weeks. 



Table IV. — Effect of Ammonium Sulfate. 



Analyses. Per cent. 



Treatment. N(total). N(by MgO). SOj. PiOs. 



Check 2.05 0.168 0.75 0.93 



N 2.93 0.364 2.10 I . 14 



0.88 0.196 1.35 0.21 



The ratio 2N/SO3 in ammonium sulfate is 28/80 = 0.351, that of total 

 nitrogen to sulfur increase is 0.652; and of nitrogen by MgO 0.145. The 

 intake of sulfur when this fertilizer is used is less than is required for the 

 nitrogen then, but in excess of that required to be combined with the 

 nitrogen determined by MgO.** Limestone was found to depress the 

 sulfur intake from ammonium sulfate. Since injury was greater in sec- 

 tions so treated, the injury is not proportional to the intake of sulfur. 

 The intake of phosphorus was increased by the addition of ammonium 

 sulfate, probably due to acidity developed in the soil. 



Table V shows the total nitrogen content of some plants from Sections 

 264 (ammonium sulfate and lime) and 281 (ammonium sulfate). Samples 



* Mayer''* states that the addition of soluble potassium salts to a soil causes a 

 partial replacement of the sodium. 



** The author would not care to report the presence of ammonium salts in plants 

 not fed with it. It seems, rather, that MgO has caused some decomposition of the 

 organic material; the error due to this is assumed to be the same in both samples. 



