| The effects of nitrogen fertilizers on water absorbent and nutrients holding ability of water retaining agent(WRA) were studied by determining water absorbent rate and amounts of absorbed and fixed fertilizers by WRA in different nitrogen fertilizers,such as urea,ammonium bicarbonate,ammonium nitrate,ammonium sulfate,and ammonium chloride.The results showed that the water absorbent ability of the WRA decreased obviously along with the increase of concentrations of various fertilizers.Nitrogen fertilizers had stronger influence on polyacrylic salt polymer than on polyacrylic salt-polyacry lamide polymer.The effects of nitrogen fertilizers on the water absorbent rate were: urea |