title: Magnesium Fertilizer-Induced Increase of Symbiotic Microorganisms Improves Forage Growth and Quality.
abstract: Magnesium (Mg) plays important roles in photosynthesis and protein synthesis; however, latent Mg deficiencies are common phenomena that can influence food quality. Nevertheless, the effects of Mg fertilizer additions on plant carbon (C):nitrogen (N):phosphorus (P) stoichiometry, an important index of food quality, are unclear and the underlying mechanisms unexplored. We conducted a greenhouse experiment using low-Mg in situ soil without and with a gradient of Mg additions to investigate the effect of Mg fertilizer on growth and stoichiometry of maize and soybean and also measure these plants' main symbiotic microorganisms: arbuscular mycorrhizal fungi (AMF) and rhizobium, respectively. Our results showed that Mg addition significantly improved both plant species' growth and also increased N and P concentrations in soybean and maize, respectively, resulting in low C:N ratio and high N:P ratio in soybean and low C:P and N:P ratios in maize. These results presumably stemmed from the increase of nutrients supplied by activation-enhanced plant symbiotic microorganisms, an explanation supported by statistically significant positive correlations between plant stoichiometry and plants' symbiotic microorganisms' increased growth with Mg addition. We conclude that Mg supply can improve plant growth and alter plant stoichiometry via enhanced activity of plant symbiotic microorganisms. Possible mechanisms underlying this positive plant-soil feedback include an enhanced photosynthetic product flow to roots caused by adequate Mg supply.
authors.affiliation: College of Agro-Grassland Science, Nanjing Agricultural University , Nanjing 210095, People's Republic of China.
authors.forename: Jihui
authors.initials: J
authors.lastname: Chen
authors.affiliation: College of Agro-Grassland Science, Nanjing Agricultural University , Nanjing 210095, People's Republic of China.
authors.forename: Yanpeng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Hengyang Red Soil Experimental Station, Chinese Academy of Agricultural Sciences , Hengyang 421001, People's Republic of China.
authors.forename: Shilin
authors.initials: S
authors.lastname: Wen
authors.affiliation: Center for Magnesium Education & Research , 13-1255 Malama Street, Pahoa, Hawaii 96778, United States.
authors.forename: Andrea
authors.initials: A
authors.lastname: Rosanoff
authors.affiliation: College of Agro-Grassland Science, Nanjing Agricultural University , Nanjing 210095, People's Republic of China.
authors.forename: Gaowen
authors.initials: G
authors.lastname: Yang
authors.affiliation: College of Agro-Grassland Science, Nanjing Agricultural University , Nanjing 210095, People's Republic of China.
authors.forename: Xiao
authors.identifier: http://orcid.org/0000-0001-6062-7647
authors.initials: X
authors.lastname: Sun
mesh_terms: D005308:Fertilizers / Q000032:analysis*; D008274:Magnesium / Q000032:analysis / Q000378:metabolism*; D038821:Mycorrhizae / Q000254:growth & development / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology; D012231:Rhizobium / Q000254:growth & development / Q000378:metabolism*; D012988:Soil Microbiology; D013025:Glycine max / Q000737:chemistry / Q000254:growth & development* / Q000382:microbiology* / Q000502:physiology; D013559:Symbiosis; D003313:Zea mays / Q000737:chemistry / Q000254:growth & development* / Q000382:microbiology / Q000502:physiology
chemical_list: D005308:Fertilizers; D008274:Magnesium
keywords: magnesium; maize; plant growth and stoichiometry; plant symbiotic microorganisms; soybean