The effect of plant mycotrophy and soil disturbance on soil microbial activity

Abstract

In cropping systems, the choices adopted for the tillage system used and plants cultivated can strongly influence the soil microbial population and its functional profile. Arbuscular mycorrhizal fungi are an important component of soil microbiome and their mutualistic symbiosis with the majority of higher plants grant the latter a wide range of benefits. The extraradical mycelium developed by these fungi expands the volume of soil influenced and harbours a diversity of microbes establishing a distinct environment of complementary interactions. We assessed how growing plants with different levels of mycotrophy modifies the biological activity profile in the soil under Mn toxicity and whether this is modified by soil disturbance. Following mycotrophic plants, soil contained a more active microbiome than after the non-mycotrophic plants, as expressed by higher values of soil basal respiration or dehydrogenase activity. Additionally, the count of phosphorus solubilizes and activity of phosphatase were greater after mycotrophic plants.Even among mycotrophic plants, different profiles of biological activity can be distinguished after growing a legume or grass. ERM disruption by soil disturbance decreased most of the parameters studied and for phosphatase activity and P solubilizers in a more significant way. These results indicate that even under Mn toxicity, the microbiome associated with AMF symbiosis following mycotrophic plants growth presented a higher biological activity and had a differential biological response towards the stress imposed by soil disturbance, when compared with the microbiome associated with non-mycotrophic roots.

Soil health and ecosystem services

“…Arbuscular mycorrhizal fungi (AMF) are naturally occurring in agricultural soils, forming symbiotic relationships with 72% of plant species, and contribute to phosphorus uptake by crops (Christensen et al, 2022). The mycelium developed by AMF expands the volume of soil from which soil nutrients can be extracted from, and also results in diverse response to soil disturbance (Conceição et al, 2023).…”

Cumulative Impact of Herbicides and Tillage on the Soil Microbiome, Fungal Diversity and Crop Productivity under Conservation Agriculture

“…Conventional agricultural systems with intensive tillage practices decrease the activities of soil microbes and enzymes, change microbial diversity, and delay nutrient cycling, consequently reducing the stability or resilience of the soil functional status [13]. By altering the SOM content, cropping systems could also shift the balance of rhizosphere soil enzymes, microbial activities and populations toward biodiversity and function [14].…”

Cumulative Impact of Herbicides and Tillage on Soil Microbiome, Fungal Diversity and Crop Productivity under Conservation Agriculture

“…Conventional agricultural systems with intensive tillage practice decline the activities of soil microbes, enzyme, change microbial diversity, shatter nutrient cycling and consequently reduce stability or resilience of soil functional status [13]. Alteration in SOM content, cropping systems could also shift the balance of rhizosphere soil enzymes, microbial activities and population into biodiversity and function [14].…”