Abstract
In this work, a novel natural pozzolan-incorporated super-absorbent polymer composites (SAPCs), a potential soil-additive to increase water holding capacity and water use efficiency of soil, was synthesized and characterized. Consequently, barley plants have been grown on the produced SAPCs under (1) well-watered and (2) water-deficient conditions. Results showed that SAPCs could reach the highest theoretical equilibrium swelling capacities of 20,000% and 3260% (wt/wt) in pure water and saltwater. Natural pozzolan (NP) incorporation with super-absorbent polymer improves water absorption capacity and thermal stability. Under the water-deficit condition, the amendment of soil with %1 SAPCs and %1 NP suppressed the reduction of relative water content as 4-8%, while it was recorded as 14% in control plants. These results confirmed that SAPC-amended soil could hold significant amounts of water and release it to plant roots gradually as needed. In conclusion, poly(AA-co-AM)/NP SAPCs can be used as a soil additive to reduce water loss, especially in arid/semi-arid regions.