2.1 Soil Sampling for incubation experiments
Saline-sodic soils for incubation experiments were collected from a degraded wetland on 4 April 2018 in the Momoge region, Jilin Province, China. The predominant vegetation cover was Leymus chinensis (Trin.) Tzvel. with a total vegetative cover of less than 10%. The climatic averages for the year are 4.4 ℃ and a rainfall of 392 mm/y. Surface soils within 40 cm depth were collected and brought back to the laboratory. Soils were well mixed and passed through a 5 mm sieve to remove stones before incubation experiments.