Abstract
Rhododendron, an important acidophilic plant, often faces challenges in urban soils that typically have an alkaline reaction and high bulk density due to low organic matter. Understanding how biochar alleviates urban soil stresses, promotes plant growth, and enhances nitrogen use efficiency (NUE) is crucial for advancing urban landscaping. A pot experiment was conducted to investigate the effects of different doses of biochar (0%–8% w/w) on the root development and NUE of Rhododendron , with a focus on the underlying micro-ecological mechanisms. Biochar amendment dose-dependently enhanced total fine root length (57.2–85.4%) and plant NUE (94.2–199%), along with increases in the fungal-to-bacterial ratio and mycorrhizal colonization. Illumina HiSeq sequencing revealed that biochar reshaped the soil microbial community by not only suppressing N-competing bacteria (e.g., Lysobacter ) and pathogenic fungi (e.g., Dactylonectria ) but also enriching beneficial fungi (e.g., Condenascus ) and copiotrophic bacteria (e.g., Pseudomonas ). These shifts likely influenced soil N transformations. Relevantly, biochar enhanced ammonia-oxidizing bacteria (AOB) abundance but reduced nirS abundance, with concurrent increases in potential nitrification and decreases in denitrification activity. At higher application rates (4%–8%), the decreased ( nirS + nirK )/ nosZ ratio indicated a potential reduction in N 2 O emissions. Partial least squares path modeling confirmed that AOB abundance was associated with soil fertility, while nirS was linked to soil pH, with both pathways ultimately governing NUE. Overall, this study demonstrated that weakly acidic biochar could enhance the growth and NUE of acidophilic plants by selectively reshaping functional microbial communities and steering inorganic N transformation toward more efficient pathways.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by-nc-nd. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 15
Claim · model-written summary
Biochar amendment dose-dependently enhanced total fine root length of Rhododendron by 57.2–85.4%.
- Taxon
- Rhododendron
Rhododendrone0 - Treatment
- Biochar amendmente2
- Outcome
- total fine root lengthe2
- Direction
- enhancede2
- Value
- 57.2–85.4%e2
- Qualifier
- dose-dependentlye2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhododendron, an important acidophilic plant”
e2“Biochar amendment dose-dependently enhanced total fine root length (57.2–85.4%) and plant NUE (94.2–199%), along with increases in the fungal-to-bacterial ratio and mycorrhizal colonization”
Claim · model-written summary
Biochar amendment enhanced plant nitrogen use efficiency of Rhododendron by 94.2–199%.
- Taxon
- RhododendronRhododendrone0
- Treatment
- Biochar amendmente2
- Outcome
- plant NUEe2
- Direction
- enhancede2
- Value
- 94.2–199%e2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhododendron, an important acidophilic plant”
e2“Biochar amendment dose-dependently enhanced total fine root length (57.2–85.4%) and plant NUE (94.2–199%), along with increases in the fungal-to-bacterial ratio and mycorrhizal colonization”
Claim · model-written summary
Biochar amendment increased the fungal-to-bacterial ratio and mycorrhizal colonization of Rhododendron roots.
- Taxon
- RhododendronRhododendrone0
- Treatment
- Biochar amendmente2
- Outcome
- fungal-to-bacterial ratio and mycorrhizal colonizatione3
- Direction
- increasese3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhododendron, an important acidophilic plant”
e2“Biochar amendment dose-dependently enhanced total fine root length (57.2–85.4%) and plant NUE (94.2–199%), along with increases in the fungal-to-bacterial ratio and mycorrhizal colonization”
e3“along with increases in the fungal-to-bacterial ratio and mycorrhizal colonization”
Claim · model-written summary
Biochar suppressed pathogenic fungi (Dactylonectria) in the Rhododendron soil.
- Taxon
- RhododendronRhododendrone0
- Treatment
- biochare5
- Interactor
- DactylonectriaDactylonectriae4pathogen
- Outcome
- pathogenic fungie4
- Direction
- suppressinge4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhododendron, an important acidophilic plant”
e4“suppressing N-competing bacteria (e.g., Lysobacter ) and pathogenic fungi (e.g., Dactylonectria )”
e5“Illumina HiSeq sequencing revealed that biochar reshaped the soil microbial community”
Claim · model-written summary
Biochar suppressed N-competing bacteria (Lysobacter) in the Rhododendron soil.
- Taxon
- RhododendronRhododendrone0
- Treatment
- biochare5
- Interactor
- Lysobacter
Lysobactere4other - Outcome
- N-competing bacteriae4
- Direction
- suppressinge4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhododendron, an important acidophilic plant”
e4“suppressing N-competing bacteria (e.g., Lysobacter ) and pathogenic fungi (e.g., Dactylonectria )”
e5“Illumina HiSeq sequencing revealed that biochar reshaped the soil microbial community”
Claim · model-written summary
Biochar enriched beneficial fungi (Condenascus) in the Rhododendron soil.
- Taxon
- RhododendronRhododendrone0
- Treatment
- biochare5
- Interactor
- CondenascusCondenascuse7other
- Outcome
- beneficial fungie7
- Direction
- enrichinge7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhododendron, an important acidophilic plant”
e5“Illumina HiSeq sequencing revealed that biochar reshaped the soil microbial community”
e7“enriching beneficial fungi (e.g., Condenascus ) and copiotrophic bacteria (e.g., Pseudomonas )”
Claim · model-written summary
Biochar enriched copiotrophic bacteria (Pseudomonas) in the Rhododendron soil.
- Taxon
- RhododendronRhododendrone0
- Treatment
- biochare5
- Interactor
- Pseudomonas
Pseudomonase7other - Outcome
- copiotrophic bacteriae7
- Direction
- enrichinge7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhododendron, an important acidophilic plant”
e5“Illumina HiSeq sequencing revealed that biochar reshaped the soil microbial community”
e7“enriching beneficial fungi (e.g., Condenascus ) and copiotrophic bacteria (e.g., Pseudomonas )”
Claim · model-written summary
Biochar enhanced the abundance of ammonia-oxidizing bacteria (AOB) in the Rhododendron soil.
- Taxon
- RhododendronRhododendrone0
- Treatment
- biochare1
- Interactor
- ammonia-oxidizing bacteria (AOB)Nitrosomonadalese1other
- Outcome
- ammonia-oxidizing bacteria (AOB) abundancee1
- Direction
- enhancede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhododendron, an important acidophilic plant”
e1“biochar enhanced ammonia-oxidizing bacteria (AOB) abundance but reduced nirS abundance, with concurrent increases in potential nitrification and decreases in denitrification activity”
Claim · model-written summary
Biochar reduced nirS gene abundance in the Rhododendron soil.
- Taxon
- RhododendronRhododendrone0
- Treatment
- biochare1
- Gene
- nirSe1
- Outcome
- nirS abundancee1
- Direction
- reducede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhododendron, an important acidophilic plant”
e1“biochar enhanced ammonia-oxidizing bacteria (AOB) abundance but reduced nirS abundance, with concurrent increases in potential nitrification and decreases in denitrification activity”
Claim · model-written summary
Biochar increased potential nitrification in the Rhododendron soil.
- Taxon
- RhododendronRhododendrone0
- Treatment
- biochare1
- Outcome
- potential nitrificatione1
- Direction
- increasese1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhododendron, an important acidophilic plant”
e1“biochar enhanced ammonia-oxidizing bacteria (AOB) abundance but reduced nirS abundance, with concurrent increases in potential nitrification and decreases in denitrification activity”
Claim · model-written summary
Biochar decreased denitrification activity in the Rhododendron soil.
- Taxon
- RhododendronRhododendrone0
- Treatment
- biochare1
- Outcome
- denitrification activitye1
- Direction
- decreasese1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhododendron, an important acidophilic plant”
e1“biochar enhanced ammonia-oxidizing bacteria (AOB) abundance but reduced nirS abundance, with concurrent increases in potential nitrification and decreases in denitrification activity”
Claim · model-written summary
At higher application rates (4%–8%) biochar decreased the (nirS + nirK)/nosZ ratio, indicating a potential reduction in N2O emissions.
- Taxon
- RhododendronRhododendrone0
- Treatment
- At higher application rates (4%–8%)e2
- Outcome
- ( nirS + nirK )/ nosZ ratioe2
- Direction
- decreasede2
- Qualifier
- potential reduction in N 2 O emissionse2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhododendron, an important acidophilic plant”
e2“At higher application rates (4%–8%), the decreased ( nirS + nirK )/ nosZ ratio indicated a potential reduction in N 2 O emissions”
Claim · model-written summary
Soil fertility was associated with AOB abundance in the Rhododendron soil (partial least squares path model).
- Taxon
- RhododendronRhododendrone0
- Interactor
- AOBe3other
- Outcome
- soil fertilitye3
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhododendron, an important acidophilic plant”
e3“Partial least squares path modeling confirmed that AOB abundance was associated with soil fertility”
Claim · model-written summary
Soil pH was linked to nirS in the Rhododendron soil (partial least squares path model).
- Taxon
- RhododendronRhododendrone0
- Gene
- nirSe4
- Outcome
- soil pHe4
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhododendron, an important acidophilic plant”
e4“while nirS was linked to soil pH”
Claim · model-written summary
Both AOB-related and nirS-related pathways ultimately govern nitrogen use efficiency of Rhododendron (author interpretation).
- Taxon
- RhododendronRhododendrone0
- Outcome
- NUEe5
- Qualifier
- both pathwayse5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhododendron, an important acidophilic plant”
e5“with both pathways ultimately governing NUE”
The same questions in other papers
biochar · growth · RhododendronPositive and negative results
1 in the opposite direction
- negative
Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.