Laboratory simulation experiment of impact of polyacrylamide on transportation of soil water and nutrients from the loess sloping land

In order to study the impact of applied polyacrylamide (PAM) on the transportation of soil, water and nutrients from the loess sloping land during the heavy storms in the loess section, the stimulated rainfall experiment in laboratory was designed to investigate the influence of PAM on characteristics of runoff nutrients concentrations, nutrients losses and redistribution of soil water and NO-3-N in soil profile during the heavy rainstorm (rainfall intensity is 2 mm/min). The results show that, as compared with control experiments, PAM treatment has little effect on the NO-3-N loss process, however, affects significantly the variability with time of PO43--P and K＋ concentrations in runoff, and reduces the losses of PO43--P and K＋ in runoff by 82% and 84% respectively. PAM, a new type of effective soil structure-improved additive, decreases soil loss by 93%, as well as reduces the losses of NO-3-N, PO43--P and K＋ with sediment by 78%, 95% and 95% respectively. Applied PAM has changed soil water redistribution processes in soil profile, and degrades the potential hazard of the soil NO-3-N leaching loss.