The indigenous arbuscular mycorrhizal fungal colonisation potential in potato roots is affected by agricultural treatments

ArticlesThere is an urgent need to develop novel approaches to enhance sustainable agriculture while not reducing cr op yields. Arbuscular mycorrhizal (AM) fungi establish symbiotic associations with most crop plants improving plant performance and soil health. This study investigated the extent of colonisation of potato roots by indigenous AM fungi in the arable soil under conventional and organic farming systems. Potato roots had greater AM fungal colonisation levels under organic than conventional farming, though in general, root colonisation levels were extremely low in both farming systems . Pota to root AM fungal colonisation was lower with higher soil P content and higher with higher annual C input. Trap plant root AM fungal colonisation was considerably higher than in field potato roots and showed that soil mycorrhizal inoculum potential was hig her in organic than in conventional farming. Thus, the positive impact of manure application in organic fields to the potato AM fungal colonisation can be explained by previous higher total annual C fresh organic matter input and lower soil P content under treatment. Furthermore, the natural AM fungal abundance in the soil was sufficient to colonise trap plant roots, suggesting a low mycorrhizal dependence of the studied potato cultivar

Soil compaction effects on arbuscular mycorrhizal symbiosis in wheat depend on host plant variety

Background and aim sSupporting arbuscular mycorrhizal (AM) nutrient acquisition in crops may reduce the need for fertilizer inputs, leading to more cost effective and sustainable crop production. In wheat, AM fungal responsiveness and benefits of symbiosis vary among varieties. This study explored the role of soil compaction in this variation.Methods We examined in a field experiment how soil compaction affects AM fungal colonization and biomass in five spring wheat varieties, and how these varieties differ in their AM-mediated phosphorus (P) uptake. We also studied soil properties, and AM fungal community composition in roots and soil.Results Soil compaction increased AM fungal colonization in the variety Alderon, characterized by root traits that indicate inefficient P uptake. Wheat P concentration and P:N ratio in Alderon and Diskett increased with increased root AM fungal colonization and biomass. In Diskett, which is the most cultivated spring wheat variety in Sweden and has intermediate root traits, total P content per m2 also increased with root AM fungal colonization and biomass.Conclusions Some wheat varieties, potentially those characterized by P inefficient root traits, such as Alderon, may depend more on AM-mediated P uptake in compacted than in non-compacted soil. Increased P uptake with increased AM fungal colonization in Diskett suggests that efficient root and AM-mediated nutrient uptake can occur simultaneously in a modern variety. Breeding varieties that use roots and AM symbiosis as complementary strategies for nutrient uptake could improve nutrient uptake efficiency and help farmers achieve stable yields in varying conditions

Land-use intensity and host plant simultaneously shape the composition of arbuscular mycorrhizal fungal communities in a Mediterranean drained peatland

Land-use change is known to be a major threat to biodiversity and ecosystem services in Mediterranean areas. However, the potential for different host plants to modulate the effect of land-use intensification on community composition of arbuscular mycorrhizal fungi (AMF) is still poorly understood. To test the hypothesis that low land-use intensity promotes AMF diversity at different taxonomic scales and to determine whether any response is dependent upon host plant species identity, we characterised AMF communities in the roots of 10 plant species across four land use types of differing intensity in a Mediterranean peatland system. AMF were identified using 454 pyrosequencing. This revealed an overall low level of AMF richness in the peaty soils; lowest AMF richness in the intense cropping system at both virtual taxa and family level; strong modulation by the host plant of the impact of land-use intensification on AMF communities at the virtual taxa level; and a significant effect of land-use intensification on AMF communities at the family level. These findings have implications for understanding ecosystem stability and productivity and should be considered when developing soil-improvement strategies in fragile ecosystems, such as Mediterranean peatlands

Hedgerows increase the diversity and modify the composition of arbuscular mycorrhizal fungi in Mediterranean agricultural landscapes

Sustainable agriculture is essential to address global challenges such as climate change and biodiversity loss. Hedgerows enhance aboveground biodiversity and provide ecosystem services, but little is known about their impact on soil biota. Arbuscular mycorrhizal (AM) fungi are one of the key components of belowground biodiversity. We compared the diversity and composition of AM fungal communities at four farmland sites located in Central Spain, where 132 soil samples in total were collected to assess soil physical and chemical properties and the AM fungal communities. We compared the richness (number of AM fungal taxa), taxonomic, functional, and phylogenetic diversity, and structure of the AM fungal communities across three farmland habitat types, namely hedgerows, woody crops (olive groves and vineyard), and herbaceous crops (barley, sunfower, and wheat). Our results showed positive efects of hedgerows on most diversity metrics. Almost 60% of the AM fungal taxa were shared among the three farmland habitat types. Hedgerows increased AM fungal taxonomic richness (31%) and alpha diversity (25%), and especially so compared to herbaceous crops (45% and 28%, respectively). Hedgerows harbored elevated proportions of AM fungi with non-ruderal life-history strategies. AM fungal communities were more similar between hedgerows and woody crops than between hedgerows and adjacent herbaceous crops, possibly because of diferences in tillage and fertilization. Unexpectedly, hedgerows reduced phylogenetic diversity, which might be related to more selective associations of AM fungi with woody plants than with herbaceous crops. Overall, the results suggest that planting hedgerows contributes to maintain belowground diversity. Thus, European farmers should plant more hedgerows to attain the goals of the EU Biodiversity Strategy for 2030.Ministerio de Educación y Formación ProfesionalComunidad de Madrid, REMEDINALUniversidad de AlcaláFondo Europeo de Desarrollo Regional-FEDEREstonian Research Counci

Paljuliigilised vahekultuuride segud haljasväetisena mahepõllukultuuride külvikorras

Mahetaimekasvatuses on vahekultuuride ehk haljasväetiste kasvatamine üks olulisemaid mullaviljakuse säilitamise meetodeid. Traditsiooniliselt on kasutatavate haljasväetiste valik väga piiratud – enamasti kasutatakse punast või valget ristikut, kas puhaskülvis või põldheina segus ühe- või kaheaastase kultuurina külvikorras. Vahekultuuride õnnestunud kasvatamisel on võimalus vähendada ka umbrohtumust, mis on hetkel üks maheviljeluse suurematest probleemidest. Vahekultuuride lagunemisel mullas muutuvad toitained järgnevatele kultuuridele kättesaadavaks, parandades nii stabiilset varustatust toitainetega. Paljuliigilised vahekultuuride segud mõjutavad mulda laiemas võtmes kui seni valdavalt üksikliigina kasvatavad liblikõielised heintaimed

Mineraalide ja biostimulaatorite kompleksi hõlmav mahepõllukultuuride kasvatustehnoloogia

Maheviljeluses on võimalik maheväetiste ja biostimulaatorite kasutamisega põllukultuuride saaki ja saagi kvaliteeti tõsta, kuid tuleb arvestada, et see on keeruline ja võib ka kergesti ebaõnnestuda. Üldjuhul on mulda antavad maheväetised (peamiselt erinevad kivijahud) taimedele raskesti omastatavad ning vajavad taime jõudmiseks mullamikroobide abi

Structure and function of the soil microbiome underlying N2O emissions from global wetlands

Wetland soils are the greatest source of nitrous oxide (N2O), a critical greenhouse gas and ozone depleter released by microbes. Yet, microbial players and processes underlying the N2O emissions from wetland soils are poorly understood. Using in situ N2O measurements and by determining the structure and potential functional of microbial communities in 645 wetland soil samples globally, we examined the potential role of archaea, bacteria, and fungi in nitrogen (N) cycling and N2O emissions. We show that N2O emissions are higher in drained and warm wetland soils, and are correlated with functional diversity of microbes. We further provide evidence that despite their much lower abundance compared to bacteria, nitrifying archaeal abundance is a key factor explaining N2O emissions from wetland soils globally. Our data suggest that ongoing global warming and intensifying environmental change may boost archaeal nitrifiers, collectively transforming wetland soils to a greater source of N2O