关键词: 花生/高粱间作, 耐盐性, 养分含量, Na⁺/K⁺稳态, 邻体效应

Abstract: 【Objective】Soil salinization has become an important global ecological and environmental problem, and seriously threatens global agricultural sustainability and food security. The higher biodiversity of farmland (intercropping) has the capability to increase soil fertility and improve the environmental adaptability of crops.【Method】In this study, peanut cultivar “Huayu 25” and sorghum cultivar “Liaoza 15” with characteristics of salt tolerance and a high yield potential, were selected for the experiments to carry out the field planting box experiment for two consecutive years. Sole-cropped peanut (SP) and intercropped peanut (IP) experiments were then performed under normal (N) and salt stress (S) soil conditions, respectively. The experiment was comprised of four treatments: sole-cropped peanut under normal condition (N-SP), intercropped peanut under normal condition (N-IP), sole cropped peanut under salt stress condition (S-SP), and intercropped peanut under salt stress condition (S-IP). Therefore, the salt tolerance index (STI), relative interaction index (RII), Na⁺/K⁺, and rhizosphere nutrient of peanut were investigated in the present study to evaluate the response of peanut to salt stress under different planting patterns.【Result】In the peanut/sorghum intercropping system, both RII of peanut were negative. However, the negative RII was decreased significantly and the STI was increased significantly in S-IP under salt stress, especially after continuously being planted for two years. Of these, the negative RII of S-IP decreased by 66.78% in 2019 than that of in 2018, and the negative RII of S-IP decreased by 88.76% than N-IP. Furthermore, the STI of S-IP increased by 27.68% than S-SP in both 2018 and 2019. Peanut/sorghum intercropping has been found to change the overall root distribution and architecture by favoring the development of different types of roots, and also affects rhizosphere nutrients of peanut, the rhizosphere soil nutrient content of N-IP and S-IP increased by an average of 6.19% and 3.73% than N-SP and S-SP, respectively. Under salt stress, the content of soil potassium increased significantly compared with normal soil conditions, this may be the initial defensive response utilized by plants to maintain Na⁺/K⁺ homeostasis in rhizosphere soil, which regulate Na⁺/K⁺ homeostasis in peanut by influencing the Na⁺ and K⁺ selective absorption and transportation. Compared with S-SP, the leaf Na⁺/K⁺ ratio decreased by 20.63%, the leaf salinity hazard coefficient (LSHC) decreased by 53.95%, and the photosynthetic potential and light energy conversion efficiency were significantly improved. Ultimately the dry matter accumulation capacity and yield potential were improved, in which the yield potential of S-IP has the most obvious increase, and the yield of S-IP increased by 17.95% in 2019 compared with 2018.【Conclusion】Continuous peanut intercropped with sorghum under salt stress could be an effective technique to alleviate peanut negative interactions, which significantly improve STI and alleviate salt stress of peanut by improving soil nutrient status and regulating peanut Na⁺/K⁺ homeostasis, which ultimately maintained the dry matter accumulation capacity and increased yield potential.

Key words: peanut/sorghum intercropping, salt tolerance, nutrient content, Na⁺/K⁺ , homeostasis, relative interaction