Abstract
Melamine, melemine nitrate, melamine phosphate, Ammeline, guanidine carbonate, guanidine nitrate and guanylurea phosphate usually derived from calcium cyanamide or dicyandiamide were prepared for studing their properties and also their effectiveness on certain crops. The result may be summerlized as follows. 1. It was indicated that melamine compounds were not hygroscopic even though at a relative humidity of 98 per cent at 33℃ and hardly soluble in water, while guanidines were more hygroscopic and easily soluble. 2. Under waterlogged condition, ammonification tests showed that, only small portion (2-17) per cent of nitrogen contained) of these compounds converted into ammonia in the soil within 4-10 weeks incubation, where as significant quantities of guanidine carbonate in a soil appeared to have a strong reducing power especially in association with reduced iron. 3. Pot experiments were carried out, in which effectiveness of these compounds were compared with ammonim sulfate or urea. Both barley and rice did not responsive to melamine, nitrate, melamine phosphate and ammeline. It was suggested that guanidine carbonate substantially evidenced the yield of rice grain, but injured on vegetation of barley, when supplied in learger amounts.
