杨树苗根系特性及根际土壤微生物多样性对施用味精废浆的响应

目的]探讨味精废浆有机肥对杨树根系特性及根际土壤微生物多样性的作用效果,为杨树苗的培育和造林以及味精废浆有机肥的推广应用提供理论依据和技术指导。方法]以一年生欧美I-107杨树苗为试材,通过盆栽模拟方式,研究CK(不施肥)、CF(单施化肥)、CM(味精废浆)和CM+CF(味精废浆和化肥各提供50%的氮)等处理对杨树苗根系构建水平、根系吸收面积、根际土壤微生物多样性指数及地径、苗高生长的影响。结果]施用味精废浆显著促进了杨树苗根系的生长,尤其增加了毛细根的数量及在根体系中的比例。同CF相比,CM+CF处理显著增加了根系的总吸收面积和活跃吸收面积,增幅分别为76.39%和121.48%;同时,CM+CF处理的微生物多样性指数达最高值,并显著高于其它处理。此外,该处理还明显促进了杨树苗地径、苗高的生长,其中地径分别较CK,CF和CM处理显著提高45.30%,22.62%和10.78%,苗高分别显著提高42.21%,20.65%和11.46%。结论]味精废浆有机肥与化肥配施有助于改善杨树苗根系特性,并提高根际土壤微生物多样性指数,进而促进杨树苗生长。

Responses of Root Characteristics and Microbial Diversity to Application of Monosodium Glutamate Wastewater in Rhizosphere Soil of Poplar Seedlings

Objective] Exploring the effects of monosodium glutamate wastewater on root characteristics and microbial diversity in rhizosphere soil of poplar, to provide theoretical basis and technical guidance for the breeding and forestation of poplar seedlings, and the popularization and application of monosodium glutamate wastewater as well.Methods] A pot experiment including four treatments, i. e., CK(neither urea nor monosodium glutamate wastewater was applied), CF(100% of nitrogen was provided by urea), CM(100% of nitrogen was provided by monosodium glutamate wastewater) and CM+CF(50% and 50% of nitrogen were provided by monosodium glutamate wastewater and urea, respectively), was performed. The present study was conducted to determine the effects of different treatments on root construction level, root absorption area, microbial diversity index in rhizosphere soil, and the growths of ground diameter and height of poplar seedlings.Results] The application of monosodium glutamate wastewater significantly promoted the root growth and construction of poplar seedlings, especially the promotions of the fine root weight and the ratio of fine root were obvious. In contrast to CF treatment, the CM+CF treatment significantly increased the total absorption area and active absorption area of roots, and the increments were 76.39% and 121.48%, respectively. At the same time, the maximum value of microbial diversity index was observed by the use of CM+CF, which had significant differences with other treatments. Additionally, this treatment also obviously improved the growths of ground diameter and height of poplar seedlings, indicative of 45.30%, 22.62% and 10.78% increases in ground diameter and 42.21%, 20.65% and 11.46% increases in height over the treatments of CK, CF and CM, respectively.Conclusion] As a result, monosodium glutamate wastewater combined with inorganic fertilizer was beneficial to improve root characteristics and microbial diversity index in rhizosphere soil, and to promote growth of poplar seedlings.