Crop Rotation 287 
During the first part of the season these crops were feeding heavily 
on the nitrates of the soil, but the corn plot produced a larger surplus 
over the amount used than did the wheat plot. These differences noted 
above are in large part due to the corn crop being cultivated and 
having a larger growing season, thus making a longer period of more 
favorable conditions for bacterial activities. 
TABLE 2 
Series II East—Rotation Corn, Oats, Wheat 
Plot 1 Corn Plot 2 Oats Plot 3 Wheat 
Nitrates—Parts per Nitrates—Parts per Nitrates—Parts per 
Month Moisture million Moisture million Moisture million 
y 7, = OF (aa at ey 
Fresh | Incubated : Fresh | Incubated ; Fresh | Incubated 
Samples| Samples Samples} Samples Samples| Samples 
WET Ge See 22.5 8.24 32.98 22.1 28.74 55.44 21.30 | 22.35 38.61 
SANOTULE Seine Sn ay/s 23.8 5.24 29.35 20.45 14.04 40.16 21.00 12.10 40.48 
IVER spcictatiatesere: ers 19.65 3.97 25.84 17.22 5.79 23.16 17.07 9.63 25.04 
MUNG Hensye retro: se 18.05 15.61 63.28 11.01 3.59 14.36 12.70 3.66 32.96 
MUL Sire Sictsrc eyes + 16.05 | 38.11 64.76 17.21 7.73 23.19 14.18 11.18 24.20 
VAUBUIRG) 2). crn reps = ot 18.07 | 58.58 73.52 17.23 7.73 15.46 16.44 7.65 9.52 
September....... 13.11 25.91 44.18 19.84 11.95 25.94 16.07 3.81 9.20 
October. .....::... 24.52 4.22 10.59 22.85 4.41 12.44 12.95 2.08 8.30 
Total for period. . 151.84 | 344.47 83.71 210.15 72.46 188.31 
Ave. per month. . 18.98 43.05 10.46 26.26 9.05 23.53 
DISCUSSION OF TABLE 2. 
Series II East—Rotation Corn, Oats, Wheat. 
Table 2 shows that the average for the fresh samples for the eight 
months were corn, 18.98 parts, oats 10.46 parts, and wheat 9.05 parts 
of nitrate per million parts of moisture-free soil. 
The highest nitrate content of the fresh samples was found in 
August for the corn plot, in March for the oat plot and in March for 
the wheat plot. The corresponding low content was found in May for 
corn, in June for oats, and in June for wheat. 
The untreated samples showed an average of 43.05 parts for the 
corn plot, 26.26 parts for the oats and 23.53 parts for the wheat. The 
highest content for the corn plot was found in August, with June and 
July also high; for oats in March with several other months of the 
growing season high. 
The similarity in the nature and feeding habits of the oat and 
wheat crops can be correlated with the similarity in the results for these 
crops. The difference between the results of the corn plot and these 
plots is in all probability due mostly to the difference in lengths of grow- 
ing season and the cultivation received by the corn crop. 
DISCUSSION OF TABLE 3. 
Series III East—Continuous Wheat. 
Table 3 shows an average for the eight months for the nitrate con- 
tent of the fresh samples of 14.66 parts per million for the unlimed 
continuous wheat plot, and 12.78 parts per million for the limed plot. 
