Controlled‐release urea combined with fulvic acid enhanced carbon/nitrogen metabolic processes and maize growth

Abstract

BACKGROUND: Controlled-release urea (CRU) or fulvic acid (FA), when applied, have been shown to increase nitrogen (N) use efficiency (NUE) or to stimulate plant growth, yet their interactive effects are not well explored. The objective of this study was to investigate the synergistic mechanisms of CRU combined with FA (CRU + FA) on maize (Zea mays L.) growth. Through the experimental design with five treatments, the N metabolism through the transcriptomic analysis of maize leaf, endogenous hormones, photosynthesis enzymes in maize leaf and root, and maize yield and NUE were evaluated.RESULTS: Compared with CRU treatment, CRU + FA treatment significantly increased auxin, nitrate reductase, and glutamate dehydrogenase in leaf by 35.4%, 43.9%, 40.8% and 19.5%, respectively, as well as, the relative content of the leaf chlorophyll and photosynthetic rate by 14.8% and 45.6%, respectively, at 12-leaf collar stage; the carbon/nitrogen (C/N) metabolic process was significantly enriched in CRU + FA treatment by 312 and 418 genes, according to transcriptome profiles of C/N metabolic in leaves from various fertilizer treated maize; maize yield and NUE of CRU + FA treatment were increased by 6.3% and 38.4%, respectively.CONCLUSIONS: These results demonstrated that CRU + FA is a viable fertilization scheme that can enhance maize growth, yield and NUE through their synergies in improving N uptake, promoting photosynthesis, increasing C/N metabolic processes, and enhancing enzyme activities.

The Combined Application of Urea and Fulvic Acid Solution Improved Maize Carbon and Nitrogen Metabolism

“…The fertilizers and FA were applied at 225 kg N•ha −1 , 150 kg P 2 O 5 •ha −1 , 75 kg K 2 O•ha −1 , and 45 kg FA•ha −1 . The quantity of fertilizer used in the pot experiment was doubled, resulting in 4.0 g N•pot −1 , 2.6 g P 2 O 5 •pot −1 , 1.4 g K 2 O•pot −1 , and 5.4 g FA pot −1 [16,17]. These fertilizer rates were calculated based on the common practices in the area.…”

“…The color depth was shown to be positively associated with enzyme content in the sample. Using enzyme labeling equipment, measure the absorbance [optical density (OD) value] at 450 nm and use the standard curve to calculate the enzyme concentration in the sample [16,39].…”

“…Integrating inorganic fertilizer with organic amendments is an effective strategy for ensuring the sustainability of agricultural system [14,15]. Fulvic acid (FA) is a widely used amendment in soils environment that has been proved to be beneficial in promoting plant growth and increasing crop yields [16,17]. According to the extraction source of fulvic acid, it can be divided into natural and biochemical fulvic acid.…”

Regulatory effect of graphene on growth and carbon/nitrogen metabolism of maize (Zea mays L.)

“…The chlorophyll content affects the photosynthetic capacity of plants, and the level of chlorophyll content affects the efficiency of plants in absorbing carbon and accumulating carbohydrates. 33 Previous research has revealed that carbon nanotubes (CNTs) can be delivered to chloroplasts and mitochondria and can penetrate chloroplast membranes to increase light absorption due to their capacity to transfer energy. 11 Plant chloroplast volume and quantity are both increased by CNTs, which increases the chlorophyll content.…”

Fulvic acid alleviates the stress of low nitrogen on maize by promoting root development and nitrogen metabolism

“…The application of humic-like substances to maize seedlings has been shown to enhance nitrogen metabolism (Ertani et al, 2013). Furthermore, studies have demonstrated that the combined application of urea and FA solution significantly stimulated the activities of enzymes related to nitrogen metabolism in maize, leading to overall improved crop nitrogen use efficiency NUE (Gao et al, 2022;Li et al, 2022).…”