Agroecological Service Crops Drive Plant Mycorrhization in Organic Horticultural Systems

Abstract

Mycorrhizal symbiosis represents a valuable tool for increasing plant nutrient uptake, affecting system biodiversity, ecosystem services and productivity. Introduction of agroecological service crops (ASCs) in cropping systems may determine changes in weed community, that can affect the development of the mycorrhizal mycelial network in the rhizosphere, favoring or depressing the cash crop mycorrhization. Two no-till Mediterranean organic horticultural systems were considered: one located in central Italy, where organic melon was transplanted on four winter-cereals mulches (rye, spelt, barley, wheat), one located in southern Italy (Sicily), where barley (as catch crop) was intercropped in an organic young orange orchard, with the no tilled, unweeded systems taken as controls. Weed "Supporting Arbuscular Mycorrhiza" (SAM) trait, weed density and biodiversity indexes, mycorrhization of coexistent plants in the field, the external mycelial network on roots were analyzed by scanning electron microscopy, crop P uptake, yield and quality were evaluated. We verified that cereals, used as green mulches or intercropped, may drive the weed selection in favor of the SAM species, and promote the mycelial network, thus significantly increasing the mycorrhization, the P uptake, the yield and quality traits of the cash crop. This is a relevant economic factor when introducing sustainable cropping practices and assessing the overall functionality of the agroecosystem.

Can multi-cropping affect soil microbial stoichiometry and functional diversity, decreasing potential soil-borne pathogens? A study on European organic vegetable cropping systems

“…Although Glomeromycota phylum was not relevant in terms of relative abundance (Figure 8), the coexistence of rhizosphere microbial communities under cabbage-beetroot IC apparently reduced the strong inhibiting effect played by cabbage on mycorrhizal fungi population at AU site. The presence of weeds species with supporting arbuscular mycorrhizal trait, such as Capsella bursapastoris L., Senecio vulgaris L., Spergula arvensis L., and Plantago maior L. (results not shown), recorded in beetroot IC only, evidently promoted the beetroot mycorrhization (Figure 4B), overruling the inhibiting effect played by the nonmycorrhizal cabbage (Hajiboland et al, 2020;Trinchera et al, 2021). This finding underpinned the hypothesis that different species of plant in the field play a selection of rhizosphere microbiome according to the plant functional traits: here, by promoting the migration of beneficial fungi population toward the beetroot (Trinchera et al, 2016).…”

“…In fact, a positive effect of legume–cereal crop rotations on beneficial fungi (e.g., mycorrhizae) was found under Mediterranean conditions, being strongly correlated to SOC, and to occurrence and β-diversity of arbuscular mycorrhiza fungi genera (Pellegrino et al, 2020 ). In addition, crop diversification (e.g., IC, living mulch, and cover crops) seems to promote the beneficial plant–fungi symbiotic association (Trinchera et al, 2019 , 2021 ).…”

Arbuscular mycorrhizal fungi in cocoa plantation affected by different elevations and soil physical-chemical properties

“…A general point of view relates the between AMF and plants as different ecological strategies indicating functional groups form based on ecosystem conditions. The previous study has shown differences in the composition of the AMF community, for example, found in grasslands, vegetable crops, trees, forests or in certain plant species [36,[40][41][42][43].…”

Weeds: An Insidious Enemy or a Tool to Boost Mycorrhization in Cropping Systems?

“…The current agroecological approach attributes an important role to AM-host weeds, or spontaneous flora, in designing sustainable and performing agroecosystems [ 9 , 10 , 11 ]. Simard et al (2012) [ 12 ] found that different forest species are able to develop a belowground common mycorrhizal mycelial network (MMN), which implies also material transfer, such as organic C, nutrients, water, defense signals, and allelochemicals among AM plants.…”