| dc.description.abstract | Superabsorbent can be synthesized from onggok and polyacrylamide using ammonium persulfate and N,N'-methylene bis-acrylamide through grafting-crosslinking methods. Superabsorbent can be enriched with urea fertilizer with slow nutrient-release properties. This superabsorbent enrichment can overcome the losses caused by conventional urea use because urea contains nitrogen nutrient which utilization efficiency is difficult to be increased. Enrichment of superabsorbent with urea was carried out by soaking superabsorbent in urea solution. Maximum enrichment was obtained in superabsorbent soaked in 1000 ppm urea solution for 17 and 24 hours with loading percentage of 36.72 and 32.48%. The release of nitrogen was tested in static aqueous media. Superabsorbent immersed in 1000 ppm urea solution for 17 hours released nitrogen most slowly, in 5 days. Release rate of nitrogen was 0.0370 ppm/min, and the nitrogen release pattern was in accordance with the pattern of plant nutrient uptake. | en |
