272 



Proceedings of Indiana Academy of Science 



increase, which fact tends to show that lack of suitable organic matter 

 was one of the limiting factors. 



The corn plot showed a higher fresh nitrate content at all times 

 than did any of the other three plots. The highest point of 26.09 parts 

 per million was reached on July 15. This high point as well as the 

 high point on August 26, can be partly explained by the rains preceding 

 both dates. The two incubated sets showed relatively little difference, 

 which fact tends to show that the organisms present were able at this 

 time to easily change organic matter into nitrates. 



The fresh nitrate content of the oat plot was low during the whole 

 season, being the lowest during May and June when the crop was using 

 the most. The incubated samples ran much like those of the clover 

 and timothy plot, the addition of ammonium sulphate causing a substan- 

 tial increase. None of the incubated samples, however, reached the 

 high point reached by the corn plot. 



The wheat plot was low in fresh nitrates in May and the begin- 

 ning of June. The highest point, of nearly 12 parts per million, was 

 reached on August 26 following the rain which fell a few days previ- 

 ously. Mention may be here made that probably one reason why most 

 of the plots showed a fairly uniform nitrate content during the whole 

 summer is that no hard rains were received which would tend to leach 

 out the nitrates which were above that used by the crops. Therefore, 

 the nitrates stayed fairly high during the whole summer until the rains 

 of late September washed them out. Although very little nitrates were 

 produced in the non-cultivated plots during the dry season, the samples 

 still showed a fairly high content. 



TABLE III.— Series 2 East 



Date 



Plot 7 Wheat 



Mois- 

 ture 

 Per 



Cent 



Nitrate- — Parts 

 per Million 



Fresh 



Incubated 



I 



II 



Plot 8 Corn 



Mois- 

 ture 

 Per 

 Cent 



Nitrates — Parts 

 per Million 



Fresh 



Incubated 



Plot 9 Oats 



Mois- 

 ture 

 Per 



Cent 



Nitrates — Parts 

 per Million 



Fresh 



Incubated 



I 



II 



Apr. 21.... 



May 6 



May 20. . . . 



June 3 



June 17. . . . 



July 1 



July 15.... 

 July 29... 

 Aug. 12... 

 Aug. 26. . . . 



Sept. 9 



Sept. 23. .. 

 Oct. 14... 

 Oct. 30... 



Average 



28.42 

 25.16 

 23.30 

 15.15 

 14.04 

 12.87 

 16.70 

 12.09 

 10.76 

 17.20 

 14.11 

 12.61 

 25.21 

 23.07 



2.68 

 2.56 

 2.50 

 1.43 

 8.73 

 12.41 

 14.62 

 10.86 

 9.32 

 7.85 

 5.76 

 6.06 

 3.94 

 4.08 



12.08 

 6.92 

 9.54 

 12.60 

 13.95 

 17.88 

 19.07 

 22.10 

 23.29 

 22.44 

 22.81 

 17.66 

 14.19 

 13.08 



17.16 

 20.90 

 26.39 

 23.89 

 28.83 

 30.43 

 31.70 

 32.08 

 33.39 

 30.50 

 30.81 

 26.62 

 20.28 

 16.85 



27.93 

 25.23 

 25.21 

 19.31 

 18.94 

 18.48 

 21.07 

 19.09 

 17.11 

 21.93 

 16.89 

 14.68 

 21.95 

 21.18 



2.66 

 3.85 

 6.85 

 7.20 

 10 47 



25 19 



26 12 

 21 09 

 15.42 

 17.81 

 15.06 

 14.43 



9.81 

 6.23 



13.98 

 17.64 

 22.87 

 26.86 

 27.61 

 33.53 

 29. 56 

 22.81 

 22.20 

 25.49 

 21.16 

 21.23 

 19,95 

 17.54 



16.78 

 24.56 

 35.40 

 34.72 

 36.20 

 42 26 

 39 81 

 36.51 

 38.94 

 37.63 

 32.45 

 30.14 

 22.70 

 19.67 



27.35 

 24.76 

 23.00 

 16.93 

 13.42 

 12.36 

 16.03 

 12.61 

 10.45 

 17.97 

 16.05 

 15.59 

 24.27 

 22.32 



10.57 

 6.38 

 4.98 

 2.76 

 3.08 

 4.88 

 6.04 

 7.02 

 6.65 

 5.21 

 6.39 

 6 93 

 3.38 

 3.94 



12.24 

 10.68 

 22.55 

 13 64 

 11.72 

 13.65 

 10.95 

 13,80 

 12 61 

 13.43 

 12,18 

 10.83 

 7.06 

 5.16 



17.91 6.63 



15.54 26.43 



20.64 13.01 23.12 



34.13 



18.08 



13.96 

 22.89 

 20.19 

 21.54 

 24 67 

 28,50 

 29.86 

 33.14 

 32.46 

 30.42 

 25.10 

 19.64 

 18.78 

 12.75 



5.59 12.16 23.85 



Discussion of Series 2 East (Corn, Oats, Wheat). (Table III.) 



The wheat plot was low in fresh nitrates during May, in the first 

 part of June, and reached its highest point of 16 parts per million on 



