GREENHOUSE EXPERIMENTS WITH ATMOSPHERIC 
NITROGEN FERTILIZERS AND RELATED COMPOUNDS 1 
By F. E. Allison, Biochemist , and E. B. Vliet, Assistant Chemist , Fixed Nitrogen 
Research Laboratory , J. J. Skinner, Biochemist , and F. R. Reid, Assistant 
Biochemist , Soil-Fertility Investigations, Bureau of Plant Industry , United 
States Department of Agriculture 
INTRODUCTION 
In connection with a study at the Fixed Nitrogen Research Laboratory on 
the possible transformation products of cyanamid, 2 there was obtained a num¬ 
ber of materials and mixtures concerning which there is either very little known, 
or concerning which there is still some doubt as to their fertilizing value. Thus, 
in the preparation of urephos, a product was obtained in which approximately 
55 per cent of the nitrogen was present as urea, 30 to 35 per cent as guanylurea, 
5 per cent as ammonia, and the balance in undetermined forms, a small part of 
which was dicyanodiamide. There is very little data available on the use of 
guanylurea as a fertilizer, and the literature on cyanamide and especially on 
dicyanodiamide contains many conflicting statements. The experiments re¬ 
ported here deal with these nitrogenous materials, as well as others, such as 
sodium nitrate and calcium nitrate, included for comparison. In addition, a few 
experiments were included in which calcium sulphate, potassium sulphate, and 
acid phosphate, but no nitrogen compounds, were added. A portion (Table I) 
of the experimental work was conducted in 1919, but a later group (Table II) 
of pot tests was conducted during the early part of 1922. 
SOILS, PLANTS, AND FERTILIZERS USED IN THE EXPERIMENTS 
The two types of soil used were the Norfolk sandy loam, a Coastal Plain soil 
obtained from near Norfolk, Va., and the Chester loam, a Piedmont Plateau soil 
secured near McLean, Va. Both soils are rather poor and typical of a large area 
along the Atlantic coast. 
Wheat, beans, and cowpeas were grown. There was some hesitancy about using, 
legumes in an availability experiment with nitrogen materials, but since legumea 
are widely different from wheat, it was decided to include them. The results 
with wheat and beans were satisfactory from the viewpoint of the experiment, 
but the cowpea developed so many nodules that it grew luxuriantly regardless 
of the nitrogen added. These results were therefore discarded. With the 
exception of potassium sulphate and calcium sulphate, which are chemically 
pure substances, the materials 3 used, together with their composition, are as 
follows: 
1 Received for publication June 5,1924—issued Nov., 1924 These experiments were conducted at the 
Arlington Experiment Farm, Rosslyn, Va., the Soil-Fertility greenhouses being used. 
2 Crude calcium cyanamid, not hydrated or oiled. 
® The preparation of some of these materials is given in an earlier publication. See Allison, F. E. f 
Braham, J.M., and McMurtrey, J. E. field experiments with atmospheric-nitrogen fertilizers^ 
U. S. Dept. Agr. Bui. 1180, 44 p., illus. 1924. 
Journal of Agricultural Research, 
Washington, D. C. 
(971) 
Vol. XXVIII, No.O- 
May 31, 1924 
Key No. R-5 
