中国农业科学 ›› 2022, Vol. 55 ›› Issue (10): 1903-1916.doi: 10.3864/j.issn.0578-1752.2022.10.003

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

种间距离对玉米-大豆带状套作土壤理化性状及根系空间分布的影响

任俊波(),杨雪丽,陈平,杜青,彭西红,郑本川,雍太文(),杨文钰   

  1. 四川农业大学农学院/农业农村部西南作物生理生态与耕作重点实验室/四川省作物带状复合种植工程技术研究中心,成都611130
  • 收稿日期:2021-08-16 接受日期:2021-10-09 出版日期:2022-05-16 发布日期:2022-06-02
  • 联系方式: 任俊波,E-mail: 1094186424@qq.com。
  • 基金资助:
    国家科学自然基金(3187101212);国家现代农业(大豆)产业技术体系专项(CARS-04-03A)

Effects of Interspecific Distances on Soil Physicochemical Properties and Root Spatial Distribution of Maize-Soybean Relay Strip Intercropping System

REN JunBo(),YANG XueLi,CHEN Ping,DU Qing,PENG XiHong,ZHENG BenChuan,YONG TaiWen(),YANG WenYu   

  1. College of Agronomy, Sichuan Agricultural University/Key Laboratory of Crop Ecophysiology and Farming System in Southwest, Ministry of Agriculture and Rural Affairs/Sichuan Engineering Research Center for Crop Strip Intercropping System, Chengdu 611130
  • Received:2021-08-16 Accepted:2021-10-09 Published:2022-05-16 Online:2022-06-02

摘要:

【目的】探究玉米-大豆套作种间距离对土壤环境及根系空间分布的影响,以期为作物根系调控养分高效吸收提供理论依据。【方法】采用单因素随机区组试验设计,设置5种根系互作方式,其中玉米-大豆套作种间距分别为30 cm(MS30)、45 cm(MS45)、60 cm(MS60),单作玉米行间距100 cm(MM100),单作大豆行间距100 cm(SS100),研究玉米-大豆套作下土壤理化性状及根系空间分布的变化规律。【结果】玉米蜡熟期(R4)至成熟期(R6)、大豆始粒期(R5)至成熟期(R8),套作处理日平均土壤氧气含量、土壤呼吸速率随种间距离增加呈先增后减趋势;其中玉米土壤氧气含量MS45处理最高,MS30处理最低,而套作后的土壤呼吸速率均显著低于单作;大豆土壤呼吸速率以MS45处理最高,较SS100处理高130.00%,而套作后的土壤氧气含量均低于单作。与单作相比,套作玉米土壤中>5 mm水稳性团聚体含量、套作大豆土壤中5—2 mm水稳性团聚体含量、土壤NO- 3-N显著增加,其中均以MS45处理最高,较单作分别显著增加19.26%、4.49%、18.07%。共生期间,与单作相比,套作各处理玉米、大豆根系空间分布呈非对称性,套作玉米根系横向能延伸到大豆行的空间下方,纵向能下扎生长更深,套作大豆根系明显偏向大豆带生长,套作玉米和大豆根长、根表面积、根体积、根干重低于单作;玉米收获后,套作大豆根系恢复生长,在水平和垂直方向上进一步延伸,其中MS45处理的根体积高于单作。通过PCA分析,土壤养分含量和水稳性团聚体指标与根系形态参数呈正相关关系【结论】玉米-大豆带状套作合理的种间距离会促进土壤大团聚体的形成,增加土壤氧气含量,改善土壤通气环境及土壤养分状况,优化作物根系空间分布,促进根系生长发育。

关键词: 玉米-大豆套作, 种间距离, 土壤氧气含量, 土壤呼吸速率, 土壤水稳性团聚体, 根系空间分布

Abstract:

【Objective】The purpose of this study was to explore the effects of interspecific distance on soil environment and root spatial distribution of maize-soybean intercropping, so as to provide a theoretical basis for crop roots to regulate the efficient utilization of nutrients.【Method】The field experiments were used one-factor randomized block design with 5 root interaction modes: maize-soybean intercropping spacing 30 cm (MS30), 45 cm (MS45), 60 cm (MS60), maize monoculture row spacing 100 cm (MM100), and soybean monoculture row spacing 100 cm (SS100). The changes of soil oxygen content, soil respiration rate, soil nutrient content, soil aggregate and root distribution were investigated.【Result】From dough stage (R4) to maturity stage (R6) of maize, as well as from the beginning seed (R5) to full maturity (R8) of soybean, the daily average soil oxygen content and soil respiration rate of intercropping treatment initially increased and then decreased later with the increase of interspecific distance; The soil oxygen content of maize was the highest in MS45, the lowest under MS30, while the soil respiration rate of intercropping was significantly lower than the monoculture. The soil respiration rate of soybean was the highest under MS45, which was 130.00% higher than that under SS100, while the soil oxygen content of intercropping was lower than that of monoculture. Compared with monoculture, the content of water-stable aggregates >5 mm in the soil of intercropping maize, the content of water-stable aggregates of 5-2 mm in the soil of intercropping soybean and the soil NO- 3-N were significantly increased, by 19.26%, 4.49%, and 18.07%, respectively; Among which, those contens under MS45 was the highest. During the co-growing period, compared with monoculture, the spatial distribution of maize and soybean roots under each intercropping treatment was asymmetrical, and the intercropping maize roots could extend horizontally below the space of soybean rows and grow deeper vertically. The root system of intercropping soybean was obviously inclined to the growth of soybean belt, and the total root length, root surface area, root volume and root dry weight of intercropping maize and soybean were lower than that of monoculture. After the maize was harvested, the intercropping soybean root system resumed growth and further extended in the horizontal and vertical directions. The root volume of MS45 was higher than those of monoculture. PCA analysis showed that soil nutrient content and water stable aggregate index were positively correlated with root morphological parameters.【Conclusion】Reasonable interspecific distance promoted the formation of soil large aggregates, increased soil oxygen content, improved soil aeration environment and soil nutrient, optimized the spatial distribution of crop roots, and promoted root growth and development.

Key words: maize-soybean intercropping, interspecific distance, soil oxygen content, soil respiration rate, soil water-stable aggregates, roots distribution