2.1 Field trial
The experiment was conducted at the agricultural science and technology innovation and demonstration base (33° 24’ N, 120° 09’ E) of Xin Yang Agricultural Experiment Station in Yancheng City, Jiangsu Province. The base contains ameliorated coastal mudflat land with a subtropical monsoon climate (average annual temperature of 14 ℃, total annual precipitation of 1100 mm, average annual sunshine of 2200 h, frost-free period of 210 d, and an altitude of less than 5 m). The soil texture of the test field was sandy loam.