Abstract
Crop management practices can affect the soil microbial community, but it is not clear whether the effect of these practices is measurable at the wheat root–soil interface, where the plant exerts significant influence through root exudation. In this study, wheat plants were grown in soil amended with milled canola, lucerne, lupin, pea, and wheat residues with and without lime, to determine what changes occur to microbial community structure in the rhizosphere. Rhizosphere soil collected from wheat plants at the 5-leaf stage was assessed for overall microbial functional diversity using BIOLOG analysis and the diversity of the functional gene nifH using the polymerase chain reaction (PCR), terminal restriction fragment length polymorphism (T-RFLP), and cloning. Plant development was reduced in all residue amendments except lucerne, and a high positive correlation in the non-limited treatments between plant residue nitrogen (N) content and wheat shoot N suggested microbial competition for available N. Results from BIOLOG analysis indicated significant differences in rhizosphere microbial community structure due to lime, and to a lesser extent, residue type. Diversity, measured by the Shannon Diversity Index, was higher in limed rhizosphere soil, in addition to an increase in soils amended with lucerne, lupin, and pea residues compared with amendment with wheat, canola, and control soil. Each residue amendment promoted unique microbial communities determined by multi-dimensional scaling (MDS) and analysis of similarities (ANOSIM) of the BIOLOG data; the strongest effect was produced by addition of canola residues. N-fixing bacteria were also affected by lime, but residue effects were less apparent, especially between limed samples. The factor that correlated best with both BIOLOG and nifH T-RFLP data in non-limed soil was a combination of residue sodium (Na), copper (Cu), and manganese (Mn). In limed soil, phosphorus (P), calcium (Ca), and pH correlated well with BIOLOG data, and N, potassium (K), and iron (Fe) correlated with nifH T-RFLP data. A clone library of nifH sequences from control and limed, pea-amended soils revealed significant diversity amongst nifH sequences, most clustering with α-proteobacteria, and in some instances with Geobacter sulfurreducens. Clone distribution was significantly different for control soil and pea/lime soil, especially amongst the α-proteobacteria. The results suggest that rhizosphere microorganisms can be influenced by soil amendments, and change, depending on the type of residue applied. The addition of lime, however, produced the most significant changes in microbial community structure and nifH-containing rhizobacteria, highlighting the significant functional changes that occur when soil pH is increased.
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 16
Claim · model-written summary
Plant development fell under all residue amendments except lucerne.
- Taxon
- wheat
Triticum aestivumt0 - Treatment
- residue amendmentse0
- Outcome
- Plant developmente0
- Direction
- reducede0
- Qualifier
- except lucernee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plant development was reduced in all residue amendments except lucerne”
t0“wheat”
Claim · model-written summary
Residue nitrogen content positively correlated with wheat shoot nitrogen in non-limed treatments.
- Taxon
- wheatTriticum aestivume0
- Compound
- plant residue nitrogen (N) contente0
- Outcome
- wheat shoot Ne0
- Direction
- positivee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a high positive correlation in the non-limited treatments between plant residue nitrogen (N) content and wheat shoot N suggested microbial competition for available N”
Claim · model-written summary
Lime significantly altered wheat rhizosphere microbial community structure.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- limee0
- Outcome
- rhizosphere microbial community structuree0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“significant differences in rhizosphere microbial community structure due to lime”
t0“wheat”
Claim · model-written summary
Residue type also affected rhizosphere microbial community structure to a lesser extent.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- residue typee0
- Outcome
- rhizosphere microbial community structuree0
- Qualifier
- to a lesser extente0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“significant differences in rhizosphere microbial community structure due to lime, and to a lesser extent, residue type”
t0“wheat”
Claim · model-written summary
Microbial functional diversity was higher in limed rhizosphere soil.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- limede0
- Outcome
- Diversitye0
- Direction
- highere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Diversity, measured by the Shannon Diversity Index, was higher in limed rhizosphere soil”
t0“wheat”
Claim · model-written summary
Lucerne, lupin and pea residue increased diversity over wheat, canola and control soil.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- lucerne, lupin, and pea residuese0
- Outcome
- Diversitye0
- Direction
- increasee0
- Comparator
- wheat, canola, and control soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Diversity, measured by the Shannon Diversity Index, was higher in limed rhizosphere soil, in addition to an increase in soils amended with lucerne, lupin, and pea residues compared with amendment with wheat, canola, and control soil”
t0“wheat”
Claim · model-written summary
Each residue amendment promoted a distinct microbial community.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- Each residue amendmente0
- Outcome
- unique microbial communitiese0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Each residue amendment promoted unique microbial communities”
t0“wheat”
Claim · model-written summary
Canola residue had the strongest effect on microbial communities.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- addition of canola residuese0
- Outcome
- strongest effecte0
- Direction
- strongest effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the strongest effect was produced by addition of canola residues”
t0“wheat”
Claim · model-written summary
Lime affected nitrogen-fixing bacteria.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- limee0
- Outcome
- N-fixing bacteriae0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“N-fixing bacteria were also affected by lime”
t0“wheat”
Claim · model-written summary
Residue effects on nitrogen-fixing bacteria were less apparent, especially with lime.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- residuee0
- Outcome
- effectse0
- Direction
- less apparente0
- Qualifier
- especially between limed samplese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“residue effects were less apparent, especially between limed samples”
t0“wheat”
Claim · model-written summary
Residue sodium, copper and manganese best correlated with microbiome data in non-limed soil.
- Taxon
- wheatTriticum aestivumt0
- Compound
- residue sodium (Na), copper (Cu), and manganese (Mn)e0
- Outcome
- BIOLOG and nifH T-RFLP datae0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The factor that correlated best with both BIOLOG and nifH T-RFLP data in non-limed soil was a combination of residue sodium (Na), copper (Cu), and manganese (Mn)”
t0“wheat”
Claim · model-written summary
Phosphorus, calcium and pH correlated with BIOLOG data in limed soil.
- Taxon
- wheatTriticum aestivumt0
- Compound
- phosphorus (P), calcium (Ca)e0
- Outcome
- BIOLOG datae0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In limed soil, phosphorus (P), calcium (Ca), and pH correlated well with BIOLOG data”
t0“wheat”
Claim · model-written summary
Nitrogen, potassium and iron correlated with nifH data in limed soil.
- Taxon
- wheatTriticum aestivumt0
- Compound
- N, potassium (K), and iron (Fe)e0
- Outcome
- nifH T-RFLP datae0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“N, potassium (K), and iron (Fe) correlated with nifH T-RFLP data”
t0“wheat”
Claim · model-written summary
The nifH clone library showed significant sequence diversity.
- Taxon
- wheatTriticum aestivumt0
- Gene
- nifHe0
- Outcome
- diversity amongst nifH sequencese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A clone library of nifH sequences from control and limed, pea-amended soils revealed significant diversity amongst nifH sequences”
t0“wheat”
Claim · model-written summary
Most nifH sequences clustered with alpha-proteobacteria, and some with Geobacter sulfurreducens.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- clustering with α-proteobacteria, and in some instances with Geobacter sulfurreducense0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“most clustering with α-proteobacteria, and in some instances with Geobacter sulfurreducens”
t0“wheat”
Claim · model-written summary
nifH clone distribution differed significantly between control and pea/lime soil.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- pea/lime soile0
- Outcome
- Clone distributione0
- Direction
- differente0
- Comparator
- control soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Clone distribution was significantly different for control soil and pea/lime soil, especially amongst the α-proteobacteria”
t0“wheat”
The same questions in other papers
other · growth · Triticum aestivum (wheat)Positive and negative results
13 papers in the same direction as this paper · 100 in the opposite direction
- positive
- positive
- positive
110 papers more in this group
See all 114 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.