Subsoil Arbuscular Mycorrhizal Fungi for Sustainability and Climate-Smart Agriculture: A Solution Right Under Our Feet?

Abstract

With growing populations and climate change, assuring food and nutrition security is an increasingly challenging task. Climate-smart and sustainable agriculture, that is, conceiving agriculture to be resistant and resilient to a changing climate while keeping it viable in the long term, is probably the best solution. The role of soil biota and particularly arbuscular mycorrhizal (AM) fungi in this new agriculture is believed to be of paramount importance. However, the large nutrient pools and the microbiota of subsoils are rarely considered in the equation. Here we explore the potential contributions of subsoil AM fungi to a reduced and more efficient fertilization, carbon sequestration, and reduction of greenhouse gas emissions in agriculture. We discuss the use of crop rotations and cover cropping with deep rooting mycorrhizal plants, and low-disturbance management, as means of fostering subsoil AM communities. Finally, we suggest future research goals that would allow us to maximize these benefits.

Potential Effects of Microplastic on Arbuscular Mycorrhizal Fungi

“…The association of a crop-host with AMF can have positive effects on nutrient uptake and biomass yield, can enhance drought-, metal-, and salinity-tolerance, reduce nutrient leaching, improve soil structure, and increase plant biodiversity ( Thirkell et al, 2017 ). AMF have been proposed to assist in stabilizing sustainable forest and agricultural productivity in the struggle with increasing impact of GCFs ( Solaiman et al, 2014 ; Sosa-Hernández et al, 2019 ), which now include MPs. However, the colonization by AMF can also reduce yields, depending on the crop species identity and soil nutrient status ( Hoeksema et al, 2010 ).…”

“…MP induced increase in microbial activity (and mobilization of N) and N inputs could lead to more N 2 O emissions from soil. Increased N release in the soil plus atmospheric N deposition could reduce AMF performance, possibly affecting AMF’s potential to reduce N emissions from soil ( Asghari and Cavagnaro, 2012 ; Storer et al, 2018 ; Sosa-Hernández et al, 2019 ), thus fostering greenhouse gas emissions from the soil to the atmosphere. MP thus has the potential to alter the nitrogen cycle and the role of AMF in the cycle, finally leading to increased turnover rates and reduced AMF activity.…”

Improved Protocol for DNA Extraction from Subsoils Using Phosphate Lysis Buffer

“…In agricultural systems, the distinction between top-and subsoil is made based on the present or historical tillage depth, which is commonly around 20 to 30 cm [1,2]. Although subsoil accounts for the vast majority of agricultural soil [2] and its management becomes increasingly important in light of resource scarcity, [3] our knowledge on soil processes and microbial communities in subsoils is scarce compared to topsoils. Fortunately, however, the number of scientific studies investigating both top-and subsoils is steadily increasing, as the methodologies for such studies become more refined and reliably reproducible.…”

Nitrogen Type and Availability Drive Mycorrhizal Effects on Wheat Performance, Nitrogen Uptake and Recovery, and Production Sustainability

“…In addition, AM fungi can influence the soil microbial community and soil aggregation and therefore processes such as mineralization, nitrification, and denitrification (Veresoglou et al, 2012;Leifheit et al, 2014;Cavagnaro et al, 2015). Moreover, because a significant amount of the total AM fungal biomass can be located in deeper layers of the soil (Higo et al, 2013), as highlighted by Sosa-Hernández et al (2019), a portion of N that migrates down the profile can be immobilized in the fungal biomass or delivered to the plant, thus further avoiding N loss. This notwithstanding, the role of AM fungi in N plant nutrition is controversial (Smith and Smith, 2011;Corrêa et al, 2015;Wang et al, 2018).…”