StripCrop: Stribedyrkning for øget biodiversitet og modstandskraft i afgrøde og jord

Baggrund: I dag dominerer de store monokulturer det danske landskab, og det sætter biodiversiteten under pres, fordi skadedyr og sygdomme får optimale betingelser og dermed udfordrer jordens frugtbarhed. Derfor har vi brug for nye dyrkningsmetoder, der øger biodiversiteten i landskabet og samtidig fastholder høstudbytterne. Stribedyrkning med 3-5 forskellige afgrøder i striber på 3-12 meters bredde har vist sig at have positive effekter i flere udenlandske forsøg. Typisk resulterer stribedyrkning i højere biodiversitet, mere modstandsdygtige afgrøder, mere frugtbar jord, færre angreb fra skadedyr, færre sygdomme og mindre jorderosion. Formål: Resultaterne fra projektets forsøg skal gøre det muligt for økologiske landbrugere at træffe kvalificerede beslutninger med henblik på at øge biodiversiteten og samtidig øge afgrødernes robusthed samt fastholde udbytterne

Evaluation of metabarcoding primers for analysis of soil nematode communities

While recent advances in next-generation sequencing technologies have accelerated research in microbial ecology, the application of high throughput approaches to study the ecology of nematodes remains unresolved due to several issues, e.g., whether to include an initial nematode extraction step or not, the lack of consensus on the best performing primer combination, and the absence of a curated nematode reference database. The objective of this method development study was to compare different primer sets to identify the most suitable primer set for the metabarcoding of nematodes without initial nematode extraction. We tested four primer sets for amplicon sequencing: JB3/JB5 (mitochondrial, I3-M11 partition of COI gene), SSU_04F/SSU_22R (18S rRNA, V1-V2 regions), and Nemf/18Sr2b (18S rRNA, V6-V8 regions) from earlier studies, as well as MMSF/MMSR (18S rRNA, V4-V5 regions), a newly developed primer set. We used DNA from 22 nematode taxa, 10 mock communities, 20 soil samples, 4 root samples, and one bulk soil. We amplified the target regions from the DNA samples with the four different primer combinations and sequenced the amplicons on an Illumina MiSeq sequencing platform. We found that the Nemf/18Sr2b primer set was superior for detecting soil nematodes compared to the other primer sets based on our sequencing results and on the annotation of our sequence reads at the genus and species ranks. This primer set generated 74% reads of Nematoda origin in the soil samples. Additionally, this primer set did well with the mock communities, detecting all the included specimens. It also worked better in the root samples than the other primer set that was tested. Therefore, we suggest that the Nemf/18Sr2b primer set could be used to study rhizosphere soil and root associated nematodes, and this can be done without an initial nematode extraction step

Breeding selection imposed a differential selective pressure on the wheat root-associated microbiome

Plants-microbiome associations are the result of millions of years of co-evolution. Due to breeding-accelerated plant evolution in non-native and highly managed soil, plant-microbe links could have been lost. We hypothesized that post-domestication breeding of wheat changed the root-associated microbiome. To test this, we analyzed root-associated fungal and bacterial communities shortly after emergence of seedlings representing a transect of wheat evolution including modern wheat, landraces and ancestors. Numbers of observed microbial taxa were highest in landraces bred in low-input agricultural systems, and lowest in ancestors that had evolved in native soils. The microbial communities of modern cultivars were different from those of landraces and ancestors. Old wheat accessions enriched Acidobacteria and Actinobacteria, while modern cultivars enriched OTUs from Candidatus Saccharibacteria, Verrucomicrobia and Firmicutes. The fungal pathogens Fusarium, Neoascochyta and Microdochium enriched in modern cultivars. Both bacterial and fungal communities followed a neutral assembly model when bulk soil was considered as the source community, but accessions of the ancient Triticum turgidum and T. monococcum created a more isolated environment in their roots. In conclusion, wheat root-associated microbiomes have dramatically changed through a transect of breeding history

Bæredygtighedsvurdering af stribedyrkning som biodiversitetstiltag i økologisk planteavl

Rapporten belyser og vurderer det fremtidige potentiale for stribedyrkning og dyrkningssystemets bæredygtighed under danske forhold. Det sker ud fra resultater og erfaringer fra Organic RDD 6-projektet StripCrop, som gennemføres i perioden 2021 – 2024 på forskningsplatforme og hos økologiske land-mænd i et samarbejde mellem Innovationscenter for Økologisk Landbrug, Aarhus Universitet, Københavns Universitet, Nordic Beet Research (NBR) og Agrointelli/BenFarm. I rapporten er der fokus på både funktionel biodiversitet, agronomiske aspekter samt praktiske erfaringer i forbindelse med brugen af landbrugsmaskiner og autonome robotter, og stribedyrkningssystemets fordele og udfordringer. Projektets resultater sammenlignes med forskning fra sammenlignelige klimazoner

Risk assessment of the biocontrol product Nemaslug 2.0 with the active organisms Phasmarhabditis californica (strain P19D) and Moraxella osloensis

publishedVersio

Nyt projekt om stribedyrkning og biodiversitet (StripCrop)

Indenfor de seneste årtier har der været en stigende interesse for samtidig dyrkning af flere afgrøder stribevis i en mark (stribedyrkning). StripCrop er et nyt dansk projekt, som beskæftiger sig med emnet. I artiklen introduceres projektet