ATMOSPHERIC-NITROGEX FERTILIZERS. 13 
The deficiency of phosphorus in the soil is shown in Table 4. The 
yields of both cotton and corn were usually larger on the untreated 
plats than where nitrogen alone was used. With both nitrogen and 
phosphorus there was a very large increase in yields. 
AMMONIUM NITRATE, SODIUM NITRATE, AND CYANAMID ON MISCELLANEOUS CROPS. 
Experiments with the three fertilizers mentioned were made on a 
wide variety of crops, including cowpeas, soy beans, string beans, 
sweet potatoes, tomatoes, potatoes, tobacco, okra, Lima beans, 
sorghum, millet, turnips, and Sudan grass. The results were of a 
qualitative nature and hence are not here reported in detail. A few 
of the more significant effects of the fertilizer treatments are, however, 
included. 
Ammonium nitrate gave results comparable with sodium nitrate. 
The material was readily available and suitable for forcing vegetables. 
Cyanamid was much slower acting and gave lower yields because of 
its dicyanodiamid content. But even where used according to best 
practice cyanamid as the only source of nitrogen will not be a suitable 
fertilizer for quick-growing crops. 
Field Xo. 2. 
Three sets of experiments were conducted in 1919 on field No. 2, 
as follows: (1) Availability studies with ammonium nitrate and 
cyanamid at different rates of application, using sodium nitrate and 
ammonium sulphate as standards; (2) studies of the effect of lime on 
availability, using the same materials; and (3) tests of the fertilizing 
value of cyanamid and Urephos in comparison with the two standards. 
The crops grown included rye, wheat, oats, and a mixture of redtop 
and orchard grass. Planting was done December 10, 1919, just 
subsequent to broadcasting the fertilizers. A wheat drill was used 
for seeding the grains, while the grass seed was distributed by hand. 
The rye plats were harvested on June 8 and the other crops on June 
2 1 . The crops were allowed to remain on the ground until thoroughly 
dry, and then the total weights were obtained. Unfortunately there 
was no equipment available for threshing and hence the grain yields 
were not determined. 
The fertilizer application included nitrogen in the different forms 
at varying rates up to 80 pounds per acre, together with phosphorus 
and potassium. The latter two elements were applied at the rate of 
80 pounds of P 2 5 and 40 pounds of K 2 to all plats of Sections I and 
II except those designated as ''no fertilizer. 7 ' On Section III 65 
pounds of P 2 5 was used on all plats except those receiving Urephos, 
where the application was 90 pounds of P 2 5 . The sources of phos- 
phorus are shown later in Table 7. The fertilizers were mixed about 
one week before applying them except where cyanamid was used, it 
being applied separately. The method of making fall applications 
was to broadcast the mixtures by hand, followed by a thorough 
harrowing before seeding. The spring applications of nitrogen 
where given were broadcasted on the various plats about April 15. 
In considering the experimental results reported below it will be 
observed that in many instances the variations in yields between 
