SOILS FERTTLIZEES. 625 



humus of the soil was of special importance in connection with the cyanamid 

 decomposition. There was an active formation of urea in cyanamid in storage, 

 but no loss of nitrogen was observed. 



Further investigations on lime nitrogen, C. J. Mild (Meded. Proefstat. 

 Java-Suikerindm., 1012, No. 16, pp. J,27-527, pis. 6, fig. 1; Arch. Suikerindm. 

 Nederland. Indie, 20 {1912), Nos. 15, pp. >t31-J,T2, pi. 1, fig- 1; 16, pp. Jf81-539, 

 pis. 5). — This is a continuation of work previously noted (E. S. R., 25, p. 826). 

 The results of the whole iuA-estigatiou are summarized in the abstract below. 



Lime nitrogen as regards its transformation in the soil, C. J. Mild {Meded. 

 Proefstat. Java-Suikcrindus., 1912, No. 20, pp. 601-634; Arch. Suikerindus. 

 Nederland. Indie, 20 {1912), No. 21, pp. 1039-1012; a&s. in Chem. ZentU., 1912, 

 II, No. 16, p. 1393). — Previous investigations by the author (see above) dealt 

 with the question of the transformation of lime nitrogen in storage. The pres- 

 ent report gives an account of experiments to determine the transformation 

 processes, fertilizing value, and effect of this material in the soil under Java 

 conditions. A light and a heavy soil type were used in the experiments. The 

 more important results of these studies are summarized as follows: 



The lime nitrogen absorbed moisture and carbon dioxid from the atmosphere. 

 Under such conditions there was a loss of nitrogen by volatilization. By storing 

 the material under dry conditions the loss of nitrogen was I'educed to a min- 

 imum. Calcium cyanamid during storage formed various decomposition prod- 

 ucts which depended to a more or less extent on the time, humidity of the 

 atmosphere, and the temperatui-e. 



In heavy soils the fertilizing value was less for the old than for the new 

 product, and for this reason the Kjeldahl method did not give a true estimate 

 of the fertilizing value of the material. 



Cyanamid was much less readily soluble in water than ammonium sulphate. 

 Less cyanamid than ammonia was absorbed by the soil. 



The transformation of lime nitrogen varied considerably as between heavy, 

 strongly absorbent soils containing colloidal and catalytic substances and light, 

 less absorbent soils. In the first type of soil the transformation was in two 

 consecutive stages — (1) the production of cyanamid followed quickly by urea 

 and (2) the formation of ammonium carbonate from the urea. The first is due 

 to a chemico-physical action, whereas the second is most probably brought about 

 by micro-organisms. The ammonia was readily absorbed by the heavy soil. 



In case of the light soil the calcium cyanamid formed basic calcium cyanamid 

 salts and free cyanamid. These compounds remained stable in the soil and 

 were slowly transformed into ammonia, this slowness of transformation giving 

 a chance for the production of dicyaudiamid. The toxic action of lime nitrogen 

 in light soils when the fertilizer is applied at the time of seeding was due to 

 the presence of the cyanamid in the soil in its unchanged condition. Cyanamid 

 was strongly toxic to plants. 



Dicyandiamid, even in large amounts, did not prevent the germination of 

 seeds. In the later stages of growth of the plants dicyandiamid had a tend- 

 ency to cause a temporary drying of the tips and edges of the leaves. 



In the heavy, strongly absorbent soils rich in colloidal and catalytic sub- 

 stances the toxic action of the cyanamid was lessened largely by the hydroly- 

 sis of cyanamid to urea. In case of the light soils with little colloidal and 

 catalytic substances, the hydrolysis of the cyanamid may be prevented and 

 polymerization to dicyandiamid may take place. A thorough covering and 

 careful distribution of the lime nitrogen in the soil and an intimate contact 

 of the colloidal and catalytic material with the calcium cyanamid tend to 

 expedite the necessary transformation of the cyanamid to urea. 



