The interactions between different N

P

K fertilizers and super absorbent polymers(SAP) with different water absorbent rate (WAR) such as polyacry lamide

polyacrylic salt

and starch graft polymer were studied by determining WAR and amounts of absorbed and fixed fertilizers by SAP. The results showed that chemical fertilizers could obviously decrease the WARs of SAPs

and the WARs of SAPs were markedly decreased with the fertilizer concentration increased. However

different fertilizers had different affecting degrees. The effects of fertilizer on the WARs were: super phosphate > monoammonium phosphate > potassium sulfate > ammonium chloride > ammonium sulfate > potassium chloride> urea. When SAPs swelled in water

they absorbed and fixed the fertilizers dissolved in water while they absorbed water. The amounts of absorbed and fixed fertilizers differed with SAPs and fertilizer types. Up to a certain fertilizer concentration

it decreased with the WARs decreased. Polyacry lamide and polyacrylic salt graft polymer had stronger resistance to fertilizers than starch graft polymer.