The Effect of Adding Poly-γ-Glutamic Acid (γ-PGA) on the Moisture Content of Gypsiferous Soil Under Partial Drip Irrigation System

Abstract

The alternate partial root-zone irrigation APRI is a modern irrigation method to save irrigation water. A field experiment was conducted to study the effect of the conventional irrigation(CI) system and the APRI system, using different levels of poly-γ-glutamic acid (γ-PGA) (0, 15, 30, 60, and 120) kg ha-1 in Gypsiferous Soil, on soil moisture content and water use efficiency. The APRI method achieved the best water extraction efficiency of 3.25 kg.m-3. The depths of water added in the traditional irrigation method were (435.58, 420.52, 416.71, 410.98, and 398.67) mm, and in the alternating irrigation method, they were (390.42, 370.50, 361.27, 340.40, and 322.40) mm for the additional levels of (γ-). PGA), respectively. The APRI method achieved an abundance of irrigation water compared with the CI of (11.57, 13.50, 15.35, 20.74, and 23.66)% for the different addition levels of (γ-PGA), respectively. The decrease in moisture content with the increase in the applied water voltage. There is a direct relationship between the amount of water available to the plant and the level of addition of (γ-PGA).