Introduction of Dalbergia odorifera enhances nitrogen absorption on Eucalyptus through stimulating microbially mediated soil nitrogen-cycling

Abstract

Background There is substantial evidence that Eucalyptus for nitrogen (N) absorption and increasing the growth benefit from the introduction of N-fixing species, but the underlying mechanisms for microbially mediated soil N cycling remains unclear. Methods We investigated the changes of soil pH, soil water content (SWC), soil organic carbon (SOC), total N (TN), inorganic N (NH4+-N and NO3−-N), microbial biomass and three N-degrading enzyme activities as well as the biomass and N productivity of Eucalyptus between a pure Eucalyptus urophylla × grandis plantation (PP) and a mixed Dalbergia odorifera and Eucalyptus plantation (MP) in Guangxi Zhuang Autonomous Region, China. Results Compared with the PP site, soil pH, SWC, SOC and TN in both seasons were significantly higher at the MP site, which in turn enhanced microbial biomass and the activities of soil N-degrading enzymes. The stimulated microbial activity at the MP site likely accelerate soil N mineralization, providing more available N (NH4+-N in both seasons and NO3−-N in the wet-hot season) for Eucalyptus absorption. Overall, the N productivity of Eucalyptus at the MP site was increased by 19.7% and 21.9%, promoting the biomass increases of 15.1% and 19.2% in the dry-cold season and wet-hot season, respectively. Conclusion Our results reveal the importance of microbially mediated soil N cycling in the N absorption on Eucalyptus. Introduction of D. odorifera enhances Eucalyptus biomass and N productivity, improve soil N availability and increased soil C and N concentration, which hence can be considered to be an effective sustainable management option of Eucalyptus plantations.

A transcriptional activator from Rhizophagus irregularis regulates phosphate uptake and homeostasis in AM symbiosis during phosphorous starvation

“…Eucalyptus wood can be used as an important raw material for industrial pulp and paper making, fuel and charcoal production because of its high-density property (Rockwood et al, 2008;Kato and Hibino, 2009). Because of its economic and ecological values, it is important to enhance the productivity of Eucalyptus limited by environmental factors such as P and N (Santos et al, 2016;Yao et al, 2021;Che et al, 2022). AM symbiosis is an environmentally friendly strategy to promote the Eucalyptus plants nutrient absorption when compared with fertilizer excessive use (Smethurst, 2010).…”

Intercropping and nitrogen enhance eucalyptus productivity through the positive interaction between soil fertility factors and bacterial communities along with the maintenance of soil enzyme activities

“…Since plant growth and adaptability are intricately linked to the highly diverse array of microorganisms in the rhizosphere, a reasonable planting strategy should sustain soil microbial activity and be beneficial for the microbial community structure (Li et al, 2022; Zhang et al, 2021), including increasing soil pH, enzyme activity, organic matter, and N content (Tian et al, 2019). Introducing Dalbergia odorifera with eucalyptus has been proven to support considerable increases in biomass/yield compared with the application of synthetic fertilizer while increasing N availability and maintaining soil fertility (Yao, Goodale, et al, 2021; Yao, Zhang, et al, 2021). Furthermore, a combination of eucalyptus and Acacia mangium enhanced soil quality and increased soil microbial diversity (Koutika et al, 2020; Zagatto et al, 2019), as well as the soil organic carbon content (Forrester et al, 2010; Koutika et al, 2019).…”

Differential responses and mechanistic controls of soil phosphorus transformation in Eucalyptus plantations with N fertilization and introduced N2‐fixing tree species

“…Here, we conducted a field experiment including a pure plantation of E. urophylla × E. grandis without nitrogen fertilization (Pure) or with N‐fertilization (Fert N), and a mixed plantation of E. urophylla × E. grandis by introducing an N 2 ‐fixing tree of Dalbergia odorifera T. Chen without fertilization (N‐fixer). The great N 2 fixation efficiency and interspecific N transfer of D. odorifera have been reported in many previous studies (Lu et al ., 2013; Yao et al ., 2019), which has been widely considered as one of the effective measures for improving Eucalyptus plantations in China (Yao et al ., 2021; Zhang et al ., 2021). The main aim of this study was to explore how N fertilization or introduced N 2 ‐fixing tree species to impact soil P transformation in Eucalyptus plantations.…”