Abstract
Effects of arbuscular mycorrhizal fungi (AMF), elevated carbon dioxide (eCO2), and their interaction on nutrient accumulation of leguminous plants and soil fertility is unknown. Plant growth, concentrations of tissue nitrogen (N), phosphorus (P), and potassium (K) in 12-week-old nodulated faba bean (Vicia faba, inoculated with Rhizobium leguminosarum bv. NM353), and nutrient use efficiency were thus assessed under ambient CO2 (410/460 ppm, daytime, 07:00 a.m.–19:00 p.m./nighttime, 19:00 p.m.–07:00 a.m.) and eCO2 (550/610 ppm) for 12 weeks with or without AM fungus of Funneliformis mosseae inoculation. eCO2 favored AMF root colonization and nodule biomass production. eCO2 significantly decreased shoot N, P and K concentrations, but generally increased tissue N, P and K accumulation and their use efficiency with an increased biomass production. Meanwhile, eCO2 enhanced C allocation into soil but showed no effects on soil available N, P, and K, while AM symbiosis increased accumulation of C, N, P, and K in both plant and soil though increased soil nutrient uptake under eCO2. Moreover, plant acquisition of soil NO3−–N and NH4+–N respond differently to AMF and eCO2 treatments. As a result, the interaction between AM symbiosis and eCO2 did improve plant C accumulation and soil N, P, and K uptake, and an alternative fertilization for legume plantation should be therefore taken under upcoming atmosphere CO2 rising. Future eCO2 studies should employ multiple AMF species, with other beneficial fungal or bacterial species, to test their interactive effects on plant performance and soil nutrient availability in the field, under other global change events including warming and drought.
Highlights
The atmospheric carbon dioxide (ACO2) is predicted to exceed 550 ppm by the end of this century from the 416 ppm in March 2021
Both arbuscular mycorrhizal fungi (AMF) and elevated CO2 (eCO2) significantly increased nodule biomass, and the highest nodule biomass was observed in AMF plants grown under eCO2 (Table 1)
ECO2 significantly increased shoot, root, and total plant biomass production and decreased root/shoot ratio, regardless of whether the faba beans were colonized by F. mosseae or not (P < 0.01, Table 1)
Summary
The atmospheric carbon dioxide (ACO2) is predicted to exceed 550 ppm by the end of this century from the 416 ppm in March 2021 (https://www.co2.earth, accessed on 1 May 2021). An elevated CO2 (eCO2) concentration has a direct effect on photosynthesis, and enhancements of carbon fixation and dry matter accumulation [1,2,3,4]. The beneficial effect of eCO2 on dry matter accumulation caused changes in C, nitrogen (N), phosphorous (P), and potassium (K) concentration, and nutrient cycling from soil to plants [9]. Increased biomass productivity of plants needs more supply of nutrients to match their increased carbon assimilation under eCO2 [9,10,11]. Soil nutrient availability might decrease over oneto-seven-year eCO2 exposure owing to an increased nutrient demand by eCO2-stimulated growth [12,13]. Decreases in soil nutrient supply modulate the magnitude of the eCO2 effect on plant biomass [14]. The availability of soil nutrients plays crucial roles in determining the response of plants to eCO2
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
