Title : Effect of sodium alginate based superabsorbent polymer and irrigation deficit on water use efficiency, and growth of tomato
Today, the rapid development of technologies to improve food production while minimizing environmental impact is a top priority. Agriculture is one of the most important industries, but it consumes a considerable amount of water. Because agricultural soils, especially arid and semi-arid soils, have large pores, plants have difficulty retaining water and fertilizer. The agricultural industry has benefited from smart polymeric materials with high water and mineral retention capacity. To improve soil water retention, we synthesized a biosourced superabsorbent hydrogel (SAP) based on alginate and reinforced with caroxylated cellulose as a soil supplement. We evaluated the effects of SAP on germination and growth and development of tomatoes. The soils were amended with different rates of alginate-based SAP (i.e., 0% SAP, 0.1% SAP and 0.5% SAP) under different stress rates (0%, 30% and 70%). The results of the germination test under normal irrigation and under water stress show the absence of phytotoxicity in normal irrigation and a positive effect on germination in water stress. The results also indicate that alginate-based SAP significantly improved plant growth parameters compared to treatments without SAP. Moreover, the highest number of leaves, chlorophyll content, stem diameter, fresh and dry matter production and fertilizer uptake capacity was found in the treatment with 0.5% SAP. Therefore, by keeping more water and nutrients in the active rooting zone and reducing nutrient runoff, the application of alaginate-based SAP can increase tomato production under drought stress. It can also reduce environmental pollution.