Abstract
Improving soil quality is critical for increasing rice yield, and biochar could be a beneficial soil amendment for high yield. This study was conducted to determine the effects of continuous (repeated seasonal) applications of biochar on nitrogen (N) uptake and utilization in rice. A fixed field experiment was done in Yongan Town, Hunan Province, China, in six continuous seasons (the early and late rice-growing seasons from 2015 to 2017). Results showed that biochar application did not significantly affect soil N uptake in the first four seasons. The effect of biochar application on fertilizer N uptake was not significant in three of the first four seasons. In the fifth and sixth seasons, biochar application resulted in 14-26% increases in soil N uptake but 19-26% decreases in fertilizer N uptake. Soil N availability did not explain the increased soil N uptake with biochar application. The decreased fertilizer N uptake with biochar application was attributed to both decreased fertilizer N availability and increased N loss through ammonia volatilization. As a consequence of a compensation between the increased soil N uptake and the decreased fertilizer N uptake, the effect of biochar application on total N uptake was not significant in the fifth and sixth seasons. However, biochar application led to 7-11% increases in internal N use efficiency in the fifth and sixth seasons and 6% increase in grain yield in the sixth season. Our study suggests that the effects of repeated seasonal applications of biochar on N uptake and utilization in rice depend on the duration of biochar application. Longer continuous applications of biochar can increase internal N use efficiency and grain yield in rice with insignificant change in total N uptake.
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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 10
Claim · model-written summary
Biochar application did not significantly affect soil N uptake in the first four seasons.
- Taxon
- rice
Oryza sativat0 - Treatment
- biochar applicatione0
- Outcome
- soil N uptakee0
- Direction
- no_changeinferrede0
- Qualifier
- in the first four seasonse0
- Setting
- Yongan Town, Hunan Province, Chinae1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Continuous applications of biochar to rice”
e1“A fixed field experiment was done in Yongan Town, Hunan Province, China”
e0“Results showed that biochar application did not significantly affect soil N uptake in the first four seasons”
Claim · model-written summary
Biochar application did not have a significant effect on fertilizer N uptake in three of the first four seasons.
- Taxon
- riceOryza sativat0
- Treatment
- biochar applicatione0
- Outcome
- fertilizer N uptakee0
- Direction
- no_changeinferrede0
- Qualifier
- in three of the first four seasonse0
- Setting
- Yongan Town, Hunan Province, Chinae1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Continuous applications of biochar to rice”
e1“A fixed field experiment was done in Yongan Town, Hunan Province, China”
e0“The effect of biochar application on fertilizer N uptake was not significant in three of the first four seasons”
Claim · model-written summary
In the fifth and sixth seasons, biochar application increased soil N uptake by 14-26%.
- Taxon
- riceOryza sativat0
- Treatment
- biochar applicatione0
- Outcome
- soil N uptakee0
- Direction
- increasese0
- Value
- 14-26%e0
- Qualifier
- In the fifth and sixth seasonse0
- Setting
- Yongan Town, Hunan Province, Chinae1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Continuous applications of biochar to rice”
e1“A fixed field experiment was done in Yongan Town, Hunan Province, China”
e0“In the fifth and sixth seasons, biochar application resulted in 14-26% increases in soil N uptake but 19-26% decreases in fertilizer N uptake”
Claim · model-written summary
In the fifth and sixth seasons, biochar application decreased fertilizer N uptake by 19-26%.
- Taxon
- riceOryza sativat0
- Treatment
- biochar applicatione0
- Outcome
- fertilizer N uptakee0
- Direction
- decreasese0
- Value
- 19-26%e0
- Qualifier
- In the fifth and sixth seasonse0
- Setting
- Yongan Town, Hunan Province, Chinae1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Continuous applications of biochar to rice”
e1“A fixed field experiment was done in Yongan Town, Hunan Province, China”
e0“In the fifth and sixth seasons, biochar application resulted in 14-26% increases in soil N uptake but 19-26% decreases in fertilizer N uptake”
Claim · model-written summary
The decreased fertilizer N uptake with biochar application is attributed to decreased fertilizer N availability and increased N loss through ammonia volatilization.
- Taxon
- riceOryza sativat0
- Outcome
- decreased fertilizer N uptakee0
- Qualifier
- decreased fertilizer N availability and increased N loss through ammonia volatilizatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Continuous applications of biochar to rice”
e0“The decreased fertilizer N uptake with biochar application was attributed to both decreased fertilizer N availability and increased N loss through ammonia volatilization”
Claim · model-written summary
Soil N availability did not explain the increase in soil N uptake under biochar application.
- Taxon
- riceOryza sativat0
- Treatment
- biochar applicatione0
- Outcome
- soil N uptakee0
- Qualifier
- Soil N availability did not explaine0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Continuous applications of biochar to rice”
e0“Soil N availability did not explain the increased soil N uptake with biochar application”
Claim · model-written summary
The effect of biochar application on total N uptake was not significant in the fifth and sixth seasons.
- Taxon
- riceOryza sativat0
- Treatment
- biochar applicatione0
- Outcome
- total N uptakee0
- Direction
- no_changeinferrede0
- Qualifier
- in the fifth and sixth seasonse0
- Setting
- Yongan Town, Hunan Province, Chinae1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Continuous applications of biochar to rice”
e1“A fixed field experiment was done in Yongan Town, Hunan Province, China”
e0“the effect of biochar application on total N uptake was not significant in the fifth and sixth seasons”
Claim · model-written summary
Biochar application increased internal N use efficiency by 7-11% in the fifth and sixth seasons.
- Taxon
- riceOryza sativat0
- Treatment
- biochar applicatione0
- Outcome
- internal N use efficiencye0
- Direction
- increasese0
- Value
- 7-11%e0
- Qualifier
- in the fifth and sixth seasonse0
- Setting
- Yongan Town, Hunan Province, Chinae1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Continuous applications of biochar to rice”
e1“A fixed field experiment was done in Yongan Town, Hunan Province, China”
e0“biochar application led to 7-11% increases in internal N use efficiency in the fifth and sixth seasons and 6% increase in grain yield in the sixth season”
Claim · model-written summary
Biochar application increased grain yield by 6% in the sixth season.
- Taxon
- riceOryza sativat0
- Treatment
- biochar applicatione0
- Outcome
- grain yielde0
- Direction
- increasee0
- Value
- 6%e0
- Qualifier
- in the sixth seasone0
- Setting
- Yongan Town, Hunan Province, Chinae1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Continuous applications of biochar to rice”
e1“A fixed field experiment was done in Yongan Town, Hunan Province, China”
e0“biochar application led to 7-11% increases in internal N use efficiency in the fifth and sixth seasons and 6% increase in grain yield in the sixth season”
Claim · model-written summary
The effects of repeated seasonal biochar applications on N uptake and utilization in rice depend on the duration of application.
- Taxon
- riceOryza sativat0
- Treatment
- repeated seasonal applications of biochare0
- Outcome
- N uptake and utilizatione0
- Qualifier
- depend on the duration of biochar applicatione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Continuous applications of biochar to rice”
e0“Our study suggests that the effects of repeated seasonal applications of biochar on N uptake and utilization in rice depend on the duration of biochar application”
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