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.

Silicon nutrition counteracts salt-induced damage associated with changes in biochemical responses in apple

“…Magnesium (Mg) is the key element of chlorophyll (Chen et al 2017) and iron (Fe) is used for chlorophyll formation (Miller et al 1984). Silicon may induce internal Fe and Mg transport, leading to the synthesis of chlorophyll.…”

Interactive Effects of Nutrients and Bradyrhizobium japonicum on the Growth and Root Architecture of Soybean (Glycine max L.)

“…The effects of nutrients present in growth media on Rhizobium -legume symbioses and nitrogen fixation have been reported (Olivera et al, 2004 ; Chaudhary et al, 2008 ). Rhizobia require adequate mineral nutrients, such as carbon, nitrogen, phosphorus, potassium, magnesium, and several microelements for the metabolism involved in invading and successfully colonizing the host root system in order to establish an effective legume-plant host symbiosis (Paliya et al, 2014 ; Egamberdieva et al, 2016 , 2017 ; Chen et al, 2017 ). In the rhizosphere, high competition for nutrients and niches occurs among various kinds of organisms, including the indigenous microflora, and rhizobia colonization depends on nutrient availability (Kuzyakov and Xu, 2013 ).…”

“…Magnesium (Mg), phosphorus (P), and nitrogen (N) are essential nutrient elements in plant growth and development and are involved in photosynthesis, nucleic acid metabolism, protein synthesis, enzyme activity, carbohydrate metabolism, and nitrogen fixation (Qin et al, 2012 ; Niste et al, 2014 ; Chen et al, 2017 ). The conversion of atmospheric N into ammonium (NH 4 ), which is available to plants through the intervention of rhizobia, requires P as an essential component (Dakora and Keya, 1997 ).…”

Magnesium accumulation, partitioning and remobilization in spring maize (Zea mays L.) under magnesium supply with straw return in northeast China

“…Choudhury and Khanif also showed that the effects of soil, N and Mg on total Mg uptake (grain and straw) were significant in rice. Chen et al . explained that an adequate supply of Mg could significantly increase Mg concentrations of leaves in maize.…”

“…52 Choudhury and Khanif 53 also showed that the effects of soil, N and Mg on total Mg uptake (grain and straw) were significant in rice. Chen et al 54 explained that an adequate supply of Mg could significantly increase Mg concentrations of leaves in maize. However, Gaj et al 14 demonstrated that mineral fertilization with appropriate levels of K and P significantly influenced Mg accumulations in maize organs, except for the cob cores.…”