Effects of two super absorbent polymers on water retention capacity of soil

The effects of two super absorbent polymers,Sodium Polyacrylate(SP) and Polyacrylamide(PAM),on water retention capacity of sand,loam,and clay were evaluated by using centrifugal method.Five concentrations of these polymers,0,0.01%,0.08%,0.2%,and 1%(on dry weight basis),were added to these three soils.The results show that the amount of water retained by the soil at each suction over the range of 0.01 MPa to 1.5 MPa significantly increased with the increasing of the two polymers;The effects on sand were more obviously than loam and clay;The concentration of the two polymers were better controlled from 0.08% to 0.20% by weight,then the crop would use 83.7% of the water kept by the polymer;The effects of the two polymers on the soil water retention were nearly the same.