Poly-γ-glutamic Acid Enhances the Wheat Yield, Water Use Efficiency and Soil Physicochemical Properties of the Arid Area in the Northwest China

ABSTRACTPoly-γ-glutamic acid (γ-PGA) is an environment-friendly super absorbent polymer that can be used as a soil conditioner, which is promising to improve crop productivity and cope with soil degradation. The objectives of this study are to study the effects of γ-PGA on soil physicochemical properties and winter wheat (Triticum aestivum L. cv. Xinong 975) production in arid region of Northwest China. According to the mass ratio of γ-PGA and soil, experiment treatments consisted of four different γ-PGA application rates, which were designated as 0 (CK), 0.05% (P0.05), 0.1% (P0.1), and 0.15% (P0.15), respectively. The mixed soil samples were uniformly filled into identical plastic pots. Each treatment had three replicates randomly distributed within 12 pots. The results indicated that γ-PGA significantly increased saturated water content by 6.3-11.5%, field capacity by 8.4-15.3%, and plant available water by 5.1-12.5% compared with the CK. γ-PGA increased soil NO3−-N content and residue, and enhanced the proportions of soil macro-aggregates compared with the CK. γ-PGA increased winter wheat yield by 29.3-34.7%, and WUE by 21.2-33.3% compared with the CK. The main conclusion γ-PGA application amount of 0.05-0.1% can be used to improve soil physicochemical properties and winter wheat production in degraded soil.KEYWORDS: Poly-γ-glutamic aciddegraded soilsoil aggregatewater use efficiencywinter wheat yield Disclosure statementWe declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted.Supplementary materialSupplemental data for this article can be accessed online at https://doi.org/10.1080/03650340.2023.2170363Additional informationFundingThis study was supported by the National Natural Science Foundation of China (No. 42077011).