466 Journal of Agricultural Research voi.xii.no. s 



AMMONIA AND NITRATES 



Withers and Fraps (62, 63) added calcium carbonate to soil treated 

 with nitrogenous material and observed a gain in nitrates which was 

 greater in the calcium-carbonate soil than in the control. Koch {31) 

 reported similar results by applying lime. Fraps (jp) treated acid and 

 nonacid soils with calcium and magnesium carbonates and noted an 

 increase in nitrates in all cases, especially in the acid soil. However, 

 calcium carbonate gave better results than were obtained with mag- 

 nesium carbonate. 



By applying calcium carbonate to a soil treated with ammonium 

 sulphate, Lemmermann, Blanck, Heinitz, and Von Wlodeck {36) no- 

 ticed a loss in ammonia. Lipman, Brown, and their associates (4, 5, 

 42, 43) studied the effect of calcium carbonate on the actitivies of soil 

 microorganisms. Lipman and Brown {44) showed an increase in am- 

 monification with monocalcium phosphate [CaH4(P04)2] and dicalcium 

 phosphate [Ca2H2(P04)2], but a decrease with tricalcium phosphate 

 [Ca3(P04)2] when applied to soil. 



Wohltmann, Fischer, and Schneider {64) inoculated liquid media 

 with soil treated with magnesium oxid and lime and observed an increase 

 in both ammonification and nitrification. Hutchinson {22) observed 

 that in liquid cultures magnesium carbonate retarded nitrification in 

 practically every case, while calcium carbonate had but little influence 

 on this process. 



Vogel {57) inoculated a nitrogenous solution containing calcium 

 carbonate with a soil suspension and obtained an increase in ammonia. 

 A similar test for nitrification was made, but an increase in nitrates was 

 not obtained. Somewhat similar results were obtained by Paterson 

 and Scott (55). Hutchinson and McLennan (25) reported that calcium 

 carbonate treatments caused a slight increase in nitrification in soil. 



Greaves {21), working with a Utah soil high in lime and magnesium 

 oxid, found that calcium carbonate in all concentrations increased the 

 formation of ammonia, while magnesium carbonate retarded ammonifi- 

 cation except when applied in very small amounts. The chlorids of 

 magnesium and calcium appeared to be very toxic. With a Japanese 

 soil Machida {48), of the Japanese Experiment Station at Tokio, noted 

 that calcium chlorid retarded ammonification, while magnesium chlorid 

 increased it. He found that nitrification was favored more by the use 

 of magnesium carbonate than by calcium carbonate. 



The work of McBeth and Wright (49) showed that the chlorids, the 

 sulphates, and especially the carbonates inhibited nitrification. Lyon 

 and Bizzell (47) reported that 10 days after treatment with lime the 

 number of bacteria was doubled. 



Fred and Graul (20) concluded that the accumulation of nitrates from 

 casein or gelatin in acid soils was not materially benefited by calcium 

 carbonate. In many cases in acid soil calcium carbonate increased and 



