Combination of Humic Substances and Arbuscular Mycorrhizal Fungi Affecting Corn Plant Growth

Abstract

This study evaluates the interaction effects on corn (Zea mays L.) growth between intact humic substances (HS) extracted in an alkaline medium from three different origins (an Organosol [HS-Org], an Andisol [HS-And], and vermicompost [HS-Vc]) and the arbuscular mycorrhizal fungus (AMF) Dentiscutata heterogama. The HS were characterized by spectroscopic techniques, and different biochemical, morphological, nutritional, and AMF colonization parameters were evaluated in corn plants. The experiment was conducted in a greenhouse, and low-fertility soils sterilized after solarization were used as the substrate. Hybrid corn BR-3025 was planted, and the HS concentrations used were 5, 10, and 20 mg carbon L −1 for HS-And, HS-Vc, and HS-Org, respectively, applied 15, 25, and 45 d after emergence close to the roots. The results show that HS application and D. heterogama inoculation significantly stimulated the biomass in relation to the treatments without AMF. Carbohydrate and protein content were stimulated by HS-AMF interaction. A higher leaf content of nutrients was observed in the AMF-and HS-inoculated plants. The HS-Vc application and AMF inoculation resulted in intense stimulation, which was confirmed with a high mycorrhizal efficiency. The spore density and glomalin content were also stimulated by the three different HS applications independently of their source. The HS-Vc has intermediate structural chemical characteristics in terms of polarity and aromaticity compared with HS-Org and HS-And. The HS-Vc more strongly stimulated the plant physiological parameters when combined with the AMF inoculation. These results may indicate that the HS formed in soil and characterized by structures that are more balanced may function more effectively.

Interaction between Humic Substances and Plant Hormones for Phosphorous Acquisition

“…Maize treated with HS and inoculated with heterogamous AMF Dentiscutata displayed an increased P content of 12% [151]. Remarkable absorption of P was also observed in lettuce treated with HS and Rhizophagus irregulares [157] and in lettuce treated with HA inoculated with AMF Rhizophagus irregulares and Funneliformis mosseae [158].…”

“…Combining microorganisms with organic matter maintains soil fertility and can result in a beneficial symbiosis for plants. Organic matter allows for the development of soil biota, responsible for nutrient mineralization and therefore, plant bioavailability [151]. In this sense, combining HS and ecto-and endomycorrhizal fungi positively affect plant growth and development [151].…”

“…Organic matter allows for the development of soil biota, responsible for nutrient mineralization and therefore, plant bioavailability [151]. In this sense, combining HS and ecto-and endomycorrhizal fungi positively affect plant growth and development [151]. The most studied plant symbiotic interactions are with arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF).…”

Current Understanding of the Use of Alkaline Extractions of Soils to Investigate Soil Organic Matter and Environmental Processes

“…The study by Pinos et al (2019) evaluated the interaction between humic substances extracted from three different materials (an Organosol [HS‐Org], an Andisol [HS‐And], and vermicompost [HS‐Vc]) and the arbuscular mycorrhizal fungus (AMF) Dentiscutata heterogama and studied how this interaction affected corn ( Zea mays L.) growth. Humic substances were characterized by spectroscopic techniques and biochemical, morphological, nutritional, and AMF colonization parameters were evaluated in corn plants.…”

Root colonization by arbuscular mycorrhizal fungi (AMF) in various age classes of revegetation post-coal mine

“…AMF is one of microorganism that has a very important role in almost every ecosystem (Chairul et al 2019;Pinos et al 2019), especially in post-mining lands (Krüger et al 2017). AMF can make the relationship between the abiotic and biotic components of the ecosystem (Kumar et al 2010).…”