Biodegradable alginate hydrogel incorporated of selenide polysaccharide to improve slow-release and selenium enrichment of vegetable.

Abstract

Selenium fertilizers (Se-fertilizers) were applied to promote the growth of plant and improve the Se content in crops. However, traditional Se-fertilizers have low utilization efficiency of Se due to adsorption or leaching. Herein, Alg-g-Polyacrylamide/Se orange peel polysaccharide (AP/SeOPP) hydrogel was prepared and characterized by FT-IR, SEM, XRD and XPS. The swelling behaviors of AP8/SeOPP3 in different saline solution were investigated. Meanwhile, the rheological properties of AP8/SeOPP3 were studied. The water-retention ratio of AP8/SeOPP3 at -0.08 MPa were 84.9 %. The water-holding capacities of soil with AP8/SeOPP3 (1 wt%) was 33.8 % at 20th day. The pot experiments showed that the Se content of Chinese cabbage treated by AP8/SeOPP3 of 2 wt% was 2.67 mg/kg. Compared with control treatment, the average stem height and fresh weight of Chinese cabbage fertilizered by AP8/SeOPP3 were higher than that treated by AP8 hydrogel. The release mechanism indicated that there was the ion exchange between Cl-, PO43-, SO42- in sandy soil and SeO32- in AP8/SeOPP3 hydrogel. This work provides a feasible strategy for promoting vegetable growth and achieving Se-enrichment of crops in arid and semi-arid region.