Abstract
The differences in rhizosphere nitrification activities between high- and low- fertility soils appear to be related to differences in dissolved oxygen concentrations in the soil, implying a relationship to differences in the radial oxygen loss (ROL) of rice roots in these soils. A miniaturised Clark-type oxygen microelectrode system was used to determine rice root ROL and the rhizosphere oxygen profile, and rhizosphere nitrification activity was studied using a short-term nitrification activity assay. Rice planting significantly altered the oxygen cycling in the water-soil system due to rice root ROL. Although the oxygen content in control high-fertility soil (without rice plants) was lower than that in control low-fertility soil, high rice root ROL significantly improved the rhizosphere oxygen concentration in the high-fertility soil. High soil fertility improved the rice root growth and root porosity as well as rice root ROL, resulting in enhanced rhizosphere nitrification. High fertility also increased the content of nitrification-induced nitrate in the rhizosphere, resulting in enhanced ammonium uptake and assimilation in the rice. Although high ammonium pools in the high-fertility soil increased rhizosphere nitrification, rice root ROL might also contribute to rhizosphere nitrification improvement. This study provides new insights into the reasons that an increase in soil fertility may enhance the growth of rice. Our results suggest that an amendment of the fertiliser used in nutrient- and nitrification-poor paddy soils in the red soil regions of China may significantly promote rice growth and rice N nutrition.
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Claims 11
Claim · model-written summary
Rice planting significantly altered oxygen cycling in the water-soil system through root oxygen loss.
- Taxon
- Rice
Oryza sativae0 - Organ / stage
- rice roote0
- Outcome
- oxygen cycling in the water-soil systeme0
- Direction
- alterede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rice planting significantly altered the oxygen cycling in the water-soil system due to rice root ROL.”
Claim · model-written summary
Without rice, high-fertility soil had lower oxygen content than low-fertility soil.
- Taxon
- rice plantsOryza sativae0
- Outcome
- oxygen contente0
- Direction
- lowere0
- Comparator
- control low-fertility soile0
- Setting
- high-fertility soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the oxygen content in control high-fertility soil (without rice plants) was lower than that in control low-fertility soil”
Claim · model-written summary
High root oxygen loss increased rhizosphere oxygen in high-fertility soil.
- Taxon
- riceOryza sativae0
- Organ / stage
- roote0
- Outcome
- rhizosphere oxygen concentratione0
- Direction
- improvede0
- Qualifier
- high rice root ROLe0
- Setting
- high-fertility soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high rice root ROL significantly improved the rhizosphere oxygen concentration in the high-fertility soil.”
Claim · model-written summary
High fertility improved rice root growth and root porosity.
- Taxon
- riceOryza sativae0
- Organ / stage
- roote0
- Treatment
- High soil fertilitye0
- Outcome
- root growth and root porositye0
- Direction
- improvede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“High soil fertility improved the rice root growth and root porosity as well as rice root ROL, resulting in enhanced rhizosphere nitrification.”
Claim · model-written summary
High fertility improved rice root radial oxygen loss.
- Taxon
- riceOryza sativae0
- Treatment
- High soil fertilitye0
- Outcome
- rice root ROLe0
- Direction
- improvede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“High soil fertility improved the rice root growth and root porosity as well as rice root ROL, resulting in enhanced rhizosphere nitrification.”
Claim · model-written summary
High fertility enhanced rhizosphere nitrification.
- Taxon
- riceOryza sativae0
- Treatment
- High soil fertilitye0
- Outcome
- rhizosphere nitrificatione0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“High soil fertility improved the rice root growth and root porosity as well as rice root ROL, resulting in enhanced rhizosphere nitrification.”
Claim · model-written summary
High fertility increased rhizosphere nitrate produced by nitrification.
- Taxon
- riceOryza sativae0
- Treatment
- High fertilitye0
- Outcome
- content of nitrification-induced nitrate in the rhizospheree0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“High fertility also increased the content of nitrification-induced nitrate in the rhizosphere, resulting in enhanced ammonium uptake and assimilation in the rice.”
Claim · model-written summary
High fertility enhanced ammonium uptake and assimilation in rice.
- Taxon
- riceOryza sativae0
- Treatment
- High fertilitye0
- Outcome
- ammonium uptake and assimilatione0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“High fertility also increased the content of nitrification-induced nitrate in the rhizosphere, resulting in enhanced ammonium uptake and assimilation in the rice.”
Claim · model-written summary
The authors infer that high soil ammonium pools increased rhizosphere nitrification.
- Taxon
- riceOryza sativat0
- Outcome
- rhizosphere nitrificatione0
- Direction
- increasede0
- Qualifier
- high ammonium pools in the high-fertility soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high ammonium pools in the high-fertility soil increased rhizosphere nitrification”
t0“Rice”
Claim · model-written summary
Rice root oxygen loss may also contribute to improved rhizosphere nitrification.
- Taxon
- riceOryza sativae0
- Organ / stage
- roote0
- Outcome
- rhizosphere nitrification improvemente0
- Direction
- improvemente0
- Qualifier
- rice root ROLe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“rice root ROL might also contribute to rhizosphere nitrification improvement.”
Claim · model-written summary
The authors recommend fertilizer amendment in nutrient- and nitrification-poor paddy soils of red-soil China to promote rice growth and nitrogen nutrition.
- Taxon
- riceOryza sativae0
- Treatment
- amendment of the fertilisere0
- Outcome
- rice growth and rice N nutritione0
- Direction
- promotee0
- Setting
- red soil regions of Chinae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Our results suggest that an amendment of the fertiliser used in nutrient- and nitrification-poor paddy soils in the red soil regions of China may significantly promote rice growth and rice N nutrition.”
The same questions in other papers
soil · growth · Oryza sativa (rice)Positive and negative results
3 papers in the same direction as this paper · 2 in the opposite direction
- no effect
- no effect
- positive
2 papers more in this group
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