Leguminous cover crops and soya increased soil fungal diversity and suppressed pathotrophs caused by continuous cereal cropping

Abstract

The enrichment of soil-borne fungal pathogens and a high input of mineral fertilizer in the continuous cropping of cereal crops have raised a concern about soil health deterioration. Conversion of continuous cereal cropping to a legume-involved system alters the soil fungal community. However, when a leguminous cover crop is grown with a succeeding legume grain crop such as soya (Glycine max L. Merril), the effects on the soil fungal community when two legumes are involved in the crop system remain unclear. Thus, the effects of the cover crop on the soil fungal community under a succession of soya and a succession of maize (Zea mays L.) were clarified: a continuous wheat (Triticum aestivum L.)–maize cropping system was converted to new rotation systems with three cover crop treatments: leguminous vetch (Vicia sativa L.), a mixture of vetch and rye (Secale cereale L.), and fallow, succeeded by soya or maize in this study. The soil fungal community at the harvest of soya and maize were determined using high-throughput sequencing of ITS2 amplicons. Compared to a wheat–maize rotation system, all of the new rotation systems that involved leguminous crops or fallow increased the soil fungal diversity and suppressed pathotrophs by reducing the soil NH4+, NO3−, available K, and available P concentrations. Different cover crops changed the fungal community composition, but their effect was overwhelmed by the strong effect of succeeding soya, which induced minor shifts among the cover crop treatments under soya than maize. The Vetch–Soya system exhibited the highest fungal diversity, which have been due to an increase of symbiotrophs. Replacing wheat with mixed vetch and rye most greatly suppressed the pathotrophs, and this suppression effect was stronger when succeeded by maize than by soya. These results showed the short-term benefits of legume–legume succession and legume–cereal mixed cover crops for increasing fungal diversity and suppressing pathotrophs. Further study is needed to examine the long-term effects of Vetch–Soya on the accumulation of legume-associated pathogens.

Winter cover crop suppression methods influence on sunflower growth and rhizosphere communities

“…10. 3389/fmicb.2024.1405842 Frontiers in Microbiology 10 frontiersin.org beneficial alterations to the soil habitat due to the presence of cover crop to host more diverse fungal taxa, supporting the notion that cover crop can enrich soil biodiversity and function (Jousset et al, 2017;Yu et al, 2022). The positive correlation between enhanced fungal richness and critical sunflower growth metrics highlights the potential benefits of a diverse fungal community for plant productivity, a finding that echoes the work of Zhang et al (2022) on the role of fungal diversity in plant growth.…”

Impact of Straw Incorporation on the Physicochemical Profile and Fungal Ecology of Saline–Alkaline Soil

“…In terms of fungal function prediction, straw application increased symbiotroph and pathotroph relative abundance; however, increased pathotroph abundance is negative for soil health, which may be related to the texture of saline soils. Yu et al 2022 suggested that legume cover crops can suppress pathotrophic fungal microorganisms [ 2 , 64 ], which could inform further saline improvement trials later. We concluded that the implementation of straw returning resulted in a notable enhancement in the abundance and diversity of soil fungus, as compared to the control group.…”

Dynamic changes in fungal communities and functions in different air-curing stages of cigar tobacco leaves

“…Curvularia is the main pathotroph in tobacco leaves and is detrimental to crop quality ( Fajola, 1979 ). Saprotrophs have antagonistic effects with pathotrophs ( Yu et al, 2022 ), which may be the reason why the main pathotrophs in tobacco leaves, Curvularia , increased with a decrease in saprotrophs, Filobasidium , in the early stage of the AC process. Curvularia reached its maximum in the yellowing stage, which is also the stage of massive water loss in tobacco leaves.…”