Abstract
Farmer interest in Hawaiʻi for organic and biological inputs for crop nitrogen (N) management is increasing, however, there is little research about the how these inputs affect N losses in agricultural soils. Similarly, there has been little research examining the effect of biological fertilizers (e.g. plant growth promoting rhizobacteria) on the soil microbiome and how this might affect subsequent soil function including plant-soil-microbial nutrient flows. To address these knowledge gaps, a greenhouse study was conducted using radish plants and a special three-chambered pot design that allowed for greenhouse gas (CO2, N2O, and CH4) flux sampling and leachate collection. Treatments included a commercially available Beneficial Soil Microbe (BSM) inoculant, compost, urea, BSM + compost, and BSM + urea. Responses in above- and belowground plant growth, plant tissue micro and macronutrients, soil total nitrogen (N) and carbon (C), pH, soil nitrate and ammonium concentrations, and amount of leached nitrate and ammonium were measured. Fungal and prokaryotic community response was analyzed using a molecular barcoding approach of bacterial & archaeal 16S and fungal ITS rRNA marker genes, and drivers of community dynamics were determined using measured soil variables. Soil functional response was measured using MetaCyc predicted functional pathways for prokaryotes and FUNGuild trophic guild assignment for fungi. Results showed compost additions increased plant growth compared to the biological and synthetic fertilizer treatments. Urea increased the amount of ammonium leached from the soil, while compost increased the amount of nitrate leached. Treatments did not increase CO2 flux compared to the control. Relative to the control, urea treatments increased CH4 flux; and urea, BSM+ urea, and BSM increased N2O flux. Compost and BSM+ compost treatments shifted prokaryotic and fungal community structure relative to urea treatment or controls. No differences in soil function were found based on predicted prokaryotic functional pathways. Compost increased the amount of potential plant pathogens in the soil. Together these results showed that compost fertilizers can change soil microbial communities and nutrient availability in soils, but can also increase the prevalence of pathogenic fungi. Regular additions of high-nitrogen (N) composts to agricultural soils as part of a N fertilizer strategy are thought to be beneficial to the soil microbiome, while intensive, uninterrupted use of synthetic N fertilizers can be detrimental to soil health. Biological indicators of soil health include high microbial richness and diversity, and community composition that favors ecosystem services like efficient N nutrient cycling. Long-term trends have shown that continued, uninterrupted use of synthetic fertilization can negatively impact these factors and reduce soil function, but little is known about the ecological mechanisms behind such shifts. This study investigates treatment effects of organic and synthetic fertilizers on soil bacterial, archaeal and fungal communities, and elucidates how these inputs affect cross-domain microbial interactions. The study was conducted using a repeated measured design where radish plants were grown in the same pots for six full crop cycles after single additions of a high-N compost or urea. A molecular barcoding approach of bacterial & archaeal 16S and fungal ITS rDNA marker genes was used to determine treatment effects on microbial richness, community composition and dynamics, network “hub” taxa, and cross-domain microbial interactions. Results showed that a single addition of compost had lasting impacts on soil microbial communities, introduced new organisms into the soil system, and altered network interactions and hub taxa. Single additions of urea did not significantly alter the structure of soil microbial communities but did reduce network complexity and alter hub taxa. This study shows that nitrogen fertilization strategies have important impacts on the soil microbiome, and microbial network analyses can be a powerful tool in determining shifts in soil community ecology that might otherwise be missed when only looking at single metric indicators like richness and diversity.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. 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 18
Claim · model-written summary
Compost additions increased radish plant growth compared with the biological and synthetic fertilizer treatments.
- Taxon
- radish
Raphanus sativuse0 - Treatment
- compost additionse1
- Outcome
- plant growthe1
- Direction
- increasede1
- Comparator
- the biological and synthetic fertilizer treatmentse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a greenhouse study was conducted using radish plants”
e1“compost additions increased plant growth compared to the biological and synthetic fertilizer treatments”
Claim · model-written summary
Urea increased the amount of ammonium leached from the soil.
- Taxon
- radishRaphanus sativuse0
- Treatment
- Ureae1
- Outcome
- amount of ammonium leached from the soile1
- Direction
- increasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a greenhouse study was conducted using radish plants”
e1“Urea increased the amount of ammonium leached from the soil”
Claim · model-written summary
Compost increased the amount of nitrate leached.
- Taxon
- radishRaphanus sativuse0
- Treatment
- composte1
- Outcome
- amount of nitrate leachede1
- Direction
- increasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a greenhouse study was conducted using radish plants”
e1“compost increased the amount of nitrate leached”
Claim · model-written summary
Treatments did not increase CO2 flux compared with the control.
- Taxon
- radishRaphanus sativuse0
- Treatment
- Treatmentse1
- Outcome
- CO2 fluxe1
- Direction
- did not increasee1
- Comparator
- the controle1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a greenhouse study was conducted using radish plants”
e1“Treatments did not increase CO2 flux compared to the control”
Claim · model-written summary
Relative to the control, urea treatments increased CH4 flux.
- Taxon
- radishRaphanus sativuse0
- Treatment
- urea treatmentse1
- Outcome
- CH4 fluxe1
- Direction
- increasede1
- Comparator
- the controle1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a greenhouse study was conducted using radish plants”
e1“Relative to the control, urea treatments increased CH4 flux; and urea, BSM+ urea, and BSM increased N2O flux”
Claim · model-written summary
Relative to the control, urea increased N2O flux.
- Taxon
- radishRaphanus sativuse0
- Treatment
- ureae1
- Outcome
- N2O fluxe1
- Direction
- increasede1
- Comparator
- the controle1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a greenhouse study was conducted using radish plants”
e1“Relative to the control, urea treatments increased CH4 flux; and urea, BSM+ urea, and BSM increased N2O flux”
Claim · model-written summary
Relative to the control, BSM + urea increased N2O flux.
- Taxon
- radishRaphanus sativuse0
- Treatment
- BSM+ ureae1
- Outcome
- N2O fluxe1
- Direction
- increasede1
- Comparator
- the controle1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a greenhouse study was conducted using radish plants”
e1“Relative to the control, urea treatments increased CH4 flux; and urea, BSM+ urea, and BSM increased N2O flux”
Claim · model-written summary
Relative to the control, the BSM inoculant increased N2O flux.
- Taxon
- radishRaphanus sativuse0
- Treatment
- BSMe1
- Outcome
- N2O fluxe1
- Direction
- increasede1
- Comparator
- the controle1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a greenhouse study was conducted using radish plants”
e1“Relative to the control, urea treatments increased CH4 flux; and urea, BSM+ urea, and BSM increased N2O flux”
Claim · model-written summary
Compost shifted prokaryotic and fungal community structure relative to urea treatment or controls.
- Taxon
- radishRaphanus sativuse0
- Treatment
- Composte1
- Outcome
- prokaryotic and fungal community structuree1
- Direction
- shiftede1
- Comparator
- urea treatment or controlse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a greenhouse study was conducted using radish plants”
e1“Compost and BSM+ compost treatments shifted prokaryotic and fungal community structure relative to urea treatment or controls”
Claim · model-written summary
BSM + compost shifted prokaryotic and fungal community structure relative to urea treatment or controls.
- Taxon
- radishRaphanus sativuse0
- Treatment
- BSM+ composte1
- Outcome
- prokaryotic and fungal community structuree1
- Direction
- shiftede1
- Comparator
- urea treatment or controlse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a greenhouse study was conducted using radish plants”
e1“Compost and BSM+ compost treatments shifted prokaryotic and fungal community structure relative to urea treatment or controls”
Claim · model-written summary
No differences in soil function were found based on predicted prokaryotic functional pathways.
- Taxon
- radishRaphanus sativuse0
- Outcome
- soil functione1
- Direction
- No differencese1
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a greenhouse study was conducted using radish plants”
e1“No differences in soil function were found based on predicted prokaryotic functional pathways”
Claim · model-written summary
Compost increased the amount of potential plant pathogens in the soil.
- Taxon
- radishRaphanus sativuse0
- Treatment
- Composte1
- Interactor
- potential plant pathogense1pathogen
- Outcome
- amount of potential plant pathogens in the soile1
- Direction
- increasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a greenhouse study was conducted using radish plants”
e1“Compost increased the amount of potential plant pathogens in the soil”
Claim · model-written summary
A single addition of compost had lasting impacts on soil microbial communities.
- Taxon
- radishRaphanus sativuse0
- Treatment
- a single addition of composte1
- Outcome
- lasting impacts on soil microbial communitiese1
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“radish plants were grown in the same pots for six full crop cycles after single additions of a high-N compost or urea”
e1“a single addition of compost had lasting impacts on soil microbial communities, introduced new organisms into the soil system, and altered network interactions and hub taxa”
Claim · model-written summary
A single addition of compost introduced new organisms into the soil system.
- Taxon
- radishRaphanus sativuse0
- Treatment
- a single addition of composte1
- Outcome
- introduced new organisms into the soil systeme1
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“radish plants were grown in the same pots for six full crop cycles after single additions of a high-N compost or urea”
e1“a single addition of compost had lasting impacts on soil microbial communities, introduced new organisms into the soil system, and altered network interactions and hub taxa”
Claim · model-written summary
A single addition of compost altered network interactions and hub taxa.
- Taxon
- radishRaphanus sativuse0
- Treatment
- a single addition of composte1
- Outcome
- network interactions and hub taxae1
- Direction
- alterede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“radish plants were grown in the same pots for six full crop cycles after single additions of a high-N compost or urea”
e1“a single addition of compost had lasting impacts on soil microbial communities, introduced new organisms into the soil system, and altered network interactions and hub taxa”
Claim · model-written summary
Single additions of urea did not significantly alter the structure of soil microbial communities.
- Taxon
- radishRaphanus sativuse0
- Treatment
- Single additions of ureae1
- Outcome
- structure of soil microbial communitiese1
- Direction
- did not significantly altere1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“radish plants were grown in the same pots for six full crop cycles after single additions of a high-N compost or urea”
e1“Single additions of urea did not significantly alter the structure of soil microbial communities but did reduce network complexity and alter hub taxa”
Claim · model-written summary
Single additions of urea reduced network complexity.
- Taxon
- radishRaphanus sativuse0
- Treatment
- Single additions of ureae1
- Outcome
- network complexitye1
- Direction
- reducee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“radish plants were grown in the same pots for six full crop cycles after single additions of a high-N compost or urea”
e1“Single additions of urea did not significantly alter the structure of soil microbial communities but did reduce network complexity and alter hub taxa”
Claim · model-written summary
Single additions of urea altered hub taxa.
- Taxon
- radishRaphanus sativuse0
- Treatment
- Single additions of ureae1
- Outcome
- hub taxae1
- Direction
- altere1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“radish plants were grown in the same pots for six full crop cycles after single additions of a high-N compost or urea”
e1“Single additions of urea did not significantly alter the structure of soil microbial communities but did reduce network complexity and alter hub taxa”
The same questions in other papers
fertilization · nutrient: content · Raphanus sativus (radish)Positive and negative results
2 papers in the same direction as this paper · 22 in the opposite direction
- positive
- positive
- positive
21 papers more in this group
See all 25 papers →fertilization · growth · Raphanus sativus (radish)Positive and negative results
89 papers in the same direction as this paper · 18 in the opposite direction · 3 reporting no difference from an alternative
- no effect
- negative
- negative
107 papers more in this group
See all 111 papers →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.