Abstract: It’s inevitable trend to study water-absorbent slow release fertilizers (WASRF) incorporated fertilizer and water all in one. The characteristics and performance of water-absorbent slow release nitrogen fertilizer(WASRNF) prepared by chemical polymerization. The results indicate that water absorbency and nitrogen analysis of WASRNF is 103g/g and 30%, respectively, and WASRNF exhibits approximately neutral in pH and has very low salt index. The interpret of Infrared spectroscopy(IR) show that WASRN is copolymer of nitrogen fertilizer and water-absorbent material by hydrogen bond association, and there are many hydrophilic groups in WASRNF, which is chemical mechanism to absorb and retain water in it themselves. The results of WASRNF soaked in water indicate that WASRNF is gel swelled and not dissolved in water. The results of SEM(Scanning Electronic Microscopy) show that there exist whole heterogenous and locally homogenous, physical void and miroscopic network structure in WASNF, which is physical structure to absorb and retain water in it themselves. The results of DSC(Differential Scanning Calorimetry) and TGA(Thermogravimetry analysis) indicate that the water retained in WASRNF exist free and freezing free water state, account for more than 95% water retained in WASRNF, and non freezing water less than 5% water retained in WASRNF. The results of 7 day’s solution rate show that WASRNF exhibits the function which delay release of nitrogen in it, and is a new WASRNF.

Key words: Water-absorbent slow release nitrogen fertilizer, Characteristics, Performance