Abstract:

To explore the effects of different amendments on the soil bacterial community structure and oat growth in soda saline-alkali land, and provide a basis for efficient improvement of saline-alkali land and the high-yield cultivation of oats, a field experiment was carried out in Dongfeng Farm, Daqing City. Five treatments were set up, namely, without amendment (CK), aluminum sulfate (AS), desulfurized gypsum (DG), vinegar residue (VR) and biochar (BC). High-throughput sequencing technology was used to analyze the structure and diversity of soil bacterial communities, and the agronomic traits of oats were measured. The results showed that the four improvers significantly increased the soil bacterial community diversity (P<0.05). Among them, the number of OTUs, Chao1 index, and Ace index were the highest in the DG treatment, the Shannon index was the highest in the VR treatment, and the Simpson index was the lowest in the BC treatment. At the phylum level, Pseudomonadota, Acidobacteriota and Actinomycetota were the main phyla. The relative abundance of Pseudomonadota was the highest (29.47%) in the BC treatment, the relative abundance of Acidobacteriota was the lowest (17.12%) in the AS treatment, and the relative abundance of Actinomycetota was the lowest (11.00%) in the DG treatment. At the genus level, norank_Pyrinomonadaceae, norank_Gemmatimonadaceae and norank_Vicinamibacterales were the main genera. After the application of amendments, the plant height, spike length, 1000-grain weight, fresh weight and dry weight of oats all increased. The BC treatment effect was the most prominent. The plant height of oats was 130.37 cm, the spike length was 21.80 cm, the 1000-grain weight was 27.00 g, and the fresh weight and dry weight reached 8337.35 kg/hm² and 7141.30 kg/hm², respectively. The DG and AS treatments also promoted the growth of oats. In terms of fresh weight and dry weight, they were not as good as the BC treatment. The promoting effect of the VR treatment was relatively weak. The traits of oat plants were closely related to the α-diversity index of the soil bacterial community. In conclusion, the four amendments, aluminum sulfate, desulfurized gypsum, vinegar residue and biochar, could all improve the soil bacterial community structure and promote the growth of oats. Biochar had the best effect, followed by desulfurized gypsum and aluminum sulfate, and vinegar residue had a relatively weak effect.

Key words: soil amendments, soda saline-alkali land, oat, bacterial community, high-throughput sequencing