26 BULLETIN 1180, U. S. DEPARTMENT OF AGRICULTURE. 
Results with com. — The yields given in Table 13 again show the 
wide differences in fertility between series and within the same 
series. The results for series E for the season of 1920 should be dis- 
carded, since these plats were located on very wet soil. During the 
rainy period of early spring about half of the plants died and the area 
had to be replanted. The extremely wide variations between check 
plats of all of the series during 1921 were due primarily to weather 
conditions. The plats were located on a gentle slope, the lower ones 
being much better supplied with moisture than the upper. 
It is useless to try to state the relative merits of the fertilizers, for 
the reasons given. The observations during growth as well as yields, 
however, did not indicate any appreciable differences between urea, 
the two mixed salts, ammonium sulphate, and sodium nitrate. 
Even calcium nitrate gave a good increase in yield regardless of its 
slow start, due probably, as already stated, to the poor mechanical 
condition of the mixture when applied. The growth of corn with 
urea is shown in Plate VII, Figure 2. 
The figures given in Table 13 and elsewhere show a marked tend- 
ency for small applications of nitrogen to produce stalks rather 
than grain in many instances. The season of 1920 was especially 
favorable for a high percentage of stalks, while the reverse was true 
in 1921. This was due chiefly to two factors: (1) Fewer stalks were 
left per given area in 1921 than in 1920, thus making available more 
food, sunlight, and moisture for each plant; (2) the wet growing 
season of 1920 produced a very rapid growth and probably a limited 
root system, since plenty of plant food was available in the vicinity 
of the seedlings. As this supply neared exhaustion the late growth 
and maturity suffered, because there was not enough nitrogen to 
produce a grain yield proportionate to the large stalk production. 
The lack of a wide-spreading root system left the plants at a greater 
disadvantage than those which received no nitrogen. On the other 
hand, during the season of 1921 the early plant growth was slowed 
down because of lack of moisture. Plant development was gradual 
throughout the year, and the stalks were really smaller than normal. 
Plenty of rain at the time of seed formation favored a grain produc- 
tion proportionate to the weight of the stalk, even with the smallest 
quantities of nitrogen. These facts emphasize the importance of a 
study of the best methods of applying fertilizers, for example, in the 
drill, by side applications or broadcasting. 
Field No. 2. 
This field, a diagram of which is shown as Figure 2, is the one that 
was planted to winter crops in the fall of 1919. After harvesting 
the crops in June the soil was allowed to remain barren until the 
spring of 1921, when the experiments with cotton and corn reported 
on below were started. 
AMMONIUM NITRATE, UREA, AMMONIUM SULPHATE, AND CYANAMID (SINGLY AND IN 
MIXTURE WITH CALCIUM NITRATE). — SECTION I. 
Results with cotton. — The importance of the weather conditions 
in this experiment necessitates a special reference to this factor. 
Planting was done near the end of a very wet period and was followed 
by a prolonged period of dry hot weather. There was adequate 
moisture to produce almost perfect germination, but the subsequent 
drought caused the burning and death of a large number of plants on 
