Super Absorbent Polymers and Soil Texture Affects on Zea mays L. Physiological Response, under Drought Stress Condition

BACKGROUND: Super absorbent polymers (SAP) have been studied as soil amendments in arid and semi-arid environments, but little is known about potential use for drought stress mitigation in different soil textures. OBJECTIVES: The objective of this survey was to evaluate the role of SAP under drought stress condition on antioxidant enzymes and Corn crop production. METHODS: Current research arranged in split-split plot experiment based on completely randomized block design with three replications. The primary plots included different types of soil, including sandy and clay-loam. The subplots were categorized into three levels of drought stress, 80, 100 and 120 mm of evaporation from the pan which is named severe drought stress, mild drought stress and well-watered conditions, respectively. Five value of SAP including 0, 10, 20, 40, and 80 kg.ha-1 were applied as the sub-subsidiary factor. RESULT: The results illustrated that drought caused a significant decrease in net photosynthesis rate, leaf stomatal conductance, chlorophyll (Chl.) a+b, relative water content (RWC), plant height, and grain yield of Maize. Catalase (CAT), Super oxide dismutase (SOD), Ascorbate peroxidase (APX), Relative electrolyte conductivity (REC), and proline were significantly elevated with increase in drought stress level. Relative to the control treatment, the moderate and severe drought conditions increased water use efficiency (WUE) on average by 5.8 and 11.7%, respectively. The maximum value of grain yield (491.8 g) was recorded for clay-loam soil texture. Applying SAP under drought condition enhanced the leaf gas exchange parameters, total chlorophyll, RWC, plant height, and grain yield, while it decreased REC, proline content, CAT, SOD, and APX activity. The highest and lowest Net photosynthesis rate, leaf stomatal conductance and Chl. a+b contents were related to amounts of 80 and 10 kg.ha-1 SAP respectively. A significant increase in leaf relative water content was observed with application of 40 and 80 kg.ha-1 SAP whilst the lower amounts (10 and 20 kg.ha-1 SAP) had no significant impact on the parameter in compared with control (0 kg.ha-1 SAP). CONCLUSION: Finally recommend using SAP at a dose of 80 kg.ha-1 for dealing with drought conditions in the sandy and clay-loam soils.