关键词: 盐碱地, 土壤改良, 生长, 玉米, 腐植酸

Abstract: To obtain an understanding of the resource status of Coregonus ussuriensis, 953 samples were collected at seven stations located in the middle reaches of Amur River basin in 2013-2017. The range of fork length and body weight was 148-588 mm and 109.0-2854.9 g, respectively. Stock biomass was estimated by lengthbased cohort analysis (LCA), while population dynamics was evaluated by BevertonHolt dynamic model. The results showed that the natural mortality coefficient, total mortality coefficient, and fishing mortality coefficient was 0.284 a^-1,0.476 a^-1 and 0.192 a^-1, respectively. The current exploitation rate was 0.403. The average stock number and biomass of C. ussuriensis in the middle reaches of Amur River was 6.89×10⁶ individuals and 5463.89 t, respectively. The initial stock biomass was 6867.07 t. Results from the analysis of relative yield per recruit and biomass per recruit showed that the exploitation of C. ussuriensis resources is relatively sufficient, with no overfishing. Population decline of C. ussuriensis was mainly attributed to anthropogenic deterioration of habitat. To achieve sustainable utilization of C. ussuriensis resources and mitigate the impacts of human activities on fish stocks, regulation of harvest needs to be implemented, such as habitat restoration, increasing minimum length limits and so on.

Key words: saline-alkali soil, humic acid, growth, soil improvement, maize