68 
Journal of Agricultural Research 
Vol. XXVIII, No. 1 
11. Guanylurea sulphate decomposed to ammonia very slowly and the am¬ 
monia so formed did not accumulate but was nitrified. Where urea was used 
with guanylurea sulphate the latter did not affect ammonification but did inhibit 
nitrification for some weeks. The injurious effect was not nearly as great as in 
the case of dicyanodiamid and would probably not be observed at all under 
field conditions. 
12. Salts • of guanidin, including guanidin nitrate and guanidin carbonate 
depressed nitrification for several weeks, the period depending upon the rate of 
application. Thereafter nitrates formed quite rapidly and after 75 days guani¬ 
din carbonate had nitrified to the extent of 83, 91 and 49 per cent for the three 
rates of application used. Nitro guanidin showed a maximum nitrification of 
17 per cent after 50 days. 
13. Biguanid nitrate acted practically like an inert material. A 3 per cent 
depression in nitrates at first was followed by a 9 per cent nitrification after 50 
days. These slight differences are nearly within experimental error. 
LITERATURE CITED 
(1) Allison, F. E., Braham, J. M., and McMurtrey, J. E. 
1924. FIELD EXPERIMENTS WITH ATMOSPHERIC-NITROGEN FERTILIZERS. 
U. S. Dept. Agr. Bui. 1180, 43 p., illus. 
(2) Brioux, C. 
1910. contribution a l^tude de la cyanamide de calcium. Ann. 
Sci. Agron. (s6r. 3), 5: 241-281. 
(3) Cowie, G. A. 
1919. decomposition of cyanamide and dicyanodiamide in the soil. 
Jour. Agr. Sci., 9: 113-136, illus. 
(4) -. 
1920. THE mechanism of the decomposition of cyanamide in the soil. 
Jour. Agr. Sci., 10: 163-176, illus. 
(5) Fox, E. J., and Geldard, W. J. 
1923. THE DETERMINATION OF UREA ALONE AND IN THE PRESENCE OF 
cyanamide by means of urease. Jour. Indus, and Engin. 
Chem., 15: 743-745. 
(6) Grazia, S. de. 
1908. sulla nitrificazione di alcuni concimi azotati. Rend. Soc. 
Chim. Roma, 6: 40-41. 
(7) Henschel, G. 
1912. DAS VERHALTEN DES TECHNISCHEN CALCIUM-CYANAMIDS BEI DER 
AUFBEWAHRUNG SOWIE UNTER DEM EINFLUSS VON KULTURBODEN 
und kolloIden. 72 p. Diss. Leipzig. (Not seen). Abs. in 
Centbl. Bakt., (II) 34: 279-280, 1912. 
(8) Jacob, K. D. 
1923. DETERMINATION OF NITRATE NITROGEN IN THE PRESENCE OF CYANA¬ 
MIDE and some of its derivatives. Indus, and Engin. Chem., 
15: 1175-1177. 
(9) Kappen, H. 
1907. DIE UMWANDLUNG DES KALKSTICKSTOFFES UND SEINER ZERSETZUNGS- 
produkte im boden. Fiihling’s Landw. Ztg., 56: 122-127. 
( 10 ) -. 
1910. UEBER DIE ZERSETZUNG DES CYANAMIDS DURCH PILZE. Centbl. 
Bakt., (II) 26: 633-643. 
(11) Linter, E. 
1917. C ALCIUMC Y AN AMID UND DICY ANDIAMID ALS VEGETATIONSFAKTOREN. 
Inaug. Diss. Konigsberg, Prussia. (Not seen.) Abs. in Centbl. 
Agr. Chem., 48: 414-417, 1919. 
