Abstract:Taken biohythane residue of straw as materials, the granulation technology and fertilizer characterization of organic-inorganic granular-fertilizers were studied. The straw residue contained abundant materials such as lignin and cellulose, as well as poor viscosity. It needs to be added to the binder to increase the rate of grain of granular-fertilizers, instead of to be produced directly. While bentonite processed a wide source, low cost, excellent viscosity and expansibility, which could be used as a good soil conditioner. Besides, polyacrylamide (PAM) was a high viscosity water-soluble polymer, which could be used widely. In order to improve the physicochemical property of biohythane residue and reduce the cost of granular-fertilizer, these two binders were used to develop the granular experiment under the content of organic and nutrient for 18 formulas, which belonged to four groups. Though the comparisons of particle size, compressive strength, content of organic and total nutrient, pipe particles, water absorption, water retention and expansion, the technology and formula was optimized. The results showed that the range of particle size and compressive strength of biohythane residue respectively were(3.16±0.15)~(4.39±0.36)mm, and(6.82±0.59)~(42.95±4.78)N. Using the bentonite PAM composite binder, T3 group, of which the content of organic and total nutrient could respectively reach up to 28.86% and 15.40%, can meet the requirement of national organic inorganic fertilizer type Ⅰ. T32 showed the best capacity of water retention among T3 group, and the water absorption, water retention, expansion rate achieved to 128%, 50% and 10.02%, respectively.