Inconsistent effects of agricultural practices on soil fungal communities across 12 European long‐term experiments

Abstract

Cropping practices have a great potential to improve soil quality through changes in soil biota. Yet the effects of these soil-improving cropping systems on soil fungal communities are not well known. Here, we analysed soil fungal communities using standardized measurements in 12 long-term experiments and 20 agricultural treatments across Europe. We were interested in whether the same practices (i.e., tillage, fertilization, organic amendments and cover crops) applied across different sites have predictable and repeatable effects on soil fungal communities and guilds. The fungal communities were very variable across sites located in different soil types and climatic regions. The arbuscular mycorrhizal fungi (AMF) were the fungal guild with most unique species in individual sites, whereas plant pathogenic fungi were most shared between the sites. The fungal communities responded to the cropping practices differently in different sites and only fertilization showed a consistent effect on AMF and plant pathogenic fungi, whereas the responses to tillage, cover crops and organic amendments were site, soil and crop-species specific. We further show that the crop yield is negatively affected by cropping practices aimed at improving soil health. Yet, we show that these practices have the potential to change the fungal communities and that change in plant pathogenic fungi and

Soil Microbiomes in Apple Orchards Are Influenced by the Type of Agricultural Management but Never Match the Complexity and Connectivity of a Semi-natural Benchmark

“…Whereas the response of AMF to herbicide applications has been reported to be highly variable, AMF may negatively respond to mechanical weeding in organic crop rows, likely explaining the increased occurrence of AMF in IPM orchards ( Turrini et al, 2017 ; Mandl et al, 2018 ; Hage-Ahmed et al, 2019 ). On the other hand, we found no management effects on the number of plant pathogen reads, aligning with recent work ( Hannula et al, 2021 ). While AMF were more abundant in drive rows, pathogenic fungi were more abundant in crop rows.…”

“…Surprisingly, the number of AMF reads in organic drive rows was lower than in IPM drive rows, while we found no difference in AMF abundance between IPM and the benchmark grasslands. This is in contrast to reduced AMF abundances found under synthetic fertilization compared to a non-fertilized control and reduced AMF richness in grasslands compared to arable systems ( Hannula et al, 2021 ; Zhu et al, 2021 ). Instead, other factors may influence AMF abundance in drive rows.…”

Pasture age impacts soil fungal composition while bacteria respond to soil chemistry

“…Several of these factors interacted with each other, as identified within our variation partitioning analysis (Figure 5) leading to the need to condition analysis upon the differences in soil pH in order to identify microbial taxa that respond to soil quality indicators across the wide range of farms. This is consistent with our understanding that the impact of farm management decisions is context-dependent (Hannula et al, 2021;Kibblewhite et al, 2008). Soil pH was more associated with bacterial composition than fungal composition, consistent with previous studies of microbial composition in temperate habitats (George et al, 2019).…”

The Askov long‐term field experiment (1894–2021) represents a unique research platform#

“…Hannula et al. (2021) analyzed the fungal communities in soils from 12 long‐term European experiments, located in Belgium, Denmark, Hungary, and the United Kingdom, and including the Askov‐LTE treatments: unmanured, 1 NPK, and 1 AM. The soil fungal community response to crop management differed among different experiments, and fertilization showed only a consistent effect on arbuscular mycorrhizal fungi and plant pathogens.…”