State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an, China.
PLoS One. 2021 Jan 12;16(1):e0245365. doi: 10.1371/journal.pone.0245365. eCollection 2021.
The main forms of poly-γ-glutamic acid (γ-PGA) applied in agriculture include agricultural γ-PGA and γ-PGA super absorbent polymer (SAP). Laboratory experiments were conducted with a check treatment CK (no γ-PGA added) and two different forms of γ-PGA added to sandy loam soil (T and TM stand for γ-PGA and γ-PGA SAP) at four different soil mass ratios (0.05% (1), 0.10% (2), 0.15% (3) and 0.20% (4)) to determine their effects on sandy loam soil hydro-physical properties. Both of them could reduce the cumulative infiltration of soil water. The total available water (TAW) which the soil water content (SWC) from field water capacity (FC) to permanent wilting point (PWP) after γ-PGA added into sandy loam soil had no significant different compared with CK, and the TAW was highest at the treatment of γ-PGA with 0.10% addition amount into sandy loam soil. However, the TAW of sandy loam soil increased dramatically with the γ-PGA SAP addition amount increasing. TM3 had the highest soil water absorption among the treatments with γ-PGA SAP. The T1 to T4 treatments with γ-PGA addition slightly prolonged retention time (RT) when SWC varied from FC to PWP compared with CK. For γ-PGA SAP addition treatments, the time for SWC varied from FC to PWP was 1.48 times (TM1), 1.88 times (TM2), 2.01 times (TM3) and 2.87 times (TM4) longer than that of CK, respectively. The results of this study will provide further information for the use of these materials in agricultural application.
聚-γ-谷氨酸（γ-PGA）在农业中的主要应用形式包括农业用 γ-PGA 和 γ-PGA 高吸水性聚合物（SAP）。本研究通过室内培养试验，设置 CK（不添加 γ-PGA）和两种不同添加形式（γ-PGA、γ-PGA SAP）共四个土壤质量比（0.05%（1）、0.10%（2）、0.15%（3）和 0.20%（4））处理，研究了 γ-PGA 对砂壤土水力学性质的影响。两种 γ-PGA 处理均降低了土壤累积入渗量，与 CK 相比，添加 γ-PGA 后土壤总有效水（TAW）无明显差异，即在土壤质量比为 0.10%时 TAW 最大。而添加 γ-PGA SAP 后 TAW 随添加量的增加而显著增加，当添加量为 0.20%时 TAW 最大。在添加 γ-PGA SAP 的处理中，TM3 的土壤吸水能力最强。与 CK 相比，添加 γ-PGA 处理的土壤保留时间（RT）在土壤含水量（SWC）从田间持水量（FC）到永久萎蔫点（PWP）变化时略有延长。添加 γ-PGA SAP 处理时，SWC 从 FC 到 PWP 的时间分别比 CK 延长了 1.48 倍（TM1）、1.88 倍（TM2）、2.01 倍（TM3）和 2.87 倍（TM4）。本研究结果将为这些材料在农业应用中的应用提供进一步的信息。
