Abstract:

In order to evaluate the regulative ability of modified materials on the adsorption and desorption of potassium in sandy soil, the effect of straw modified materials which were made of straw, bentonite and PAM, on the adsorption and desorption of potassium in sandy yellow soil was carried out. The results showed that the straw modified material significantly improved the adsorption property to potassium in the sandy soil, and enhanced the fixed ability to potassium of soil. With the adding amount of PAM increasing, the adsorption amount of potassium raised. Compared to treatment F0, during 10 days, 30 days, 60 days and 90 days, the average adsorption of F3 treatment reached the highest degree, which increased by 6.1%, 9.2%, 10.9% and 13.9%. Straw modified material promoted potassium to lose from soil, but the desorption still was lower than adsorption. While the proportion of PAM in straw modified material increased, the desorption rate of potassium also was improved significantly. Compared to F0, F3 treatment in 10 days, 30 day, 60 days and 90 days experiments, potassium desorption rate increased by 6.1%, 18.2%, 17.2% and 15.4%. Straw modified materials could improve the capacity to potassium of soil, which could be applied in restoration of degraded soil.