Abstract
Excessive application of nitrogen (N) fertilizer will cause many adverse consequences in paddy fields, especially for the reduction in N use efficiency. Biochar can be used to replace part of N fertilizer for rice production. A field experiment of 2-year/four-season was conducted to investigate the effects of N fertilizer reduction combined with rice straw biochar application on rice yield, soil fertility, and N use efficiency. The experiment contained six treatments: No N application (CK), customary N application (N100), 20% N reduction (N80), 20% N reduction + biochar (N80+BC), 40% N reduction (N60), and 40% N reduction + biochar (N60+BC). Compared with N100, N reduction alone had no significant impact on the number of tillers and aboveground biomass of rice, exceptfor N60 which slightly reduced grain yield, while biochar incorporation tended to obtain higher tillers, aboveground biomass, and grain yield of rice compared with N reduction alone. The average contribution of biochar to grain yield on the basis of N80 and N60 were 5.8% and 7.7%, respectively. Notably, biochar incorporation further improved the agronomic N efficiency (54.5–309.4% over N100) and apparent N recovery (25.7–150.5% over N100) on the basis of N reduction. Furthermore, biochar application could not only maintain N nutrition level of rice, but also improve soil fertility mainly by increasing soil pH and organic matter. Therefore, integrated application of mineral N fertilizer and biochar is a feasible nutrient management measure to increase rice yield and soil fertility, and improve N use efficiency in paddy ecosystem.
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Claims 10
Claim · model-written summary
N reduction alone had no significant effect on tiller number and aboveground biomass of rice compared with N100.
- Taxon
- rice
Oryza sativae1 - Treatment
- N reduction alonee1
- Outcome
- number of tillers and aboveground biomasse1
- Direction
- no significant impacte1
- Comparator
- N100e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Compared with N100, N reduction alone had no significant impact on the number of tillers and aboveground biomass of rice, exceptfor N60 which slightly reduced grain yield”
Claim · model-written summary
N60 slightly reduced rice grain yield compared with N100.
- Taxon
- riceOryza sativae1
- Treatment
- N60e1
- Outcome
- grain yielde1
- Direction
- slightly reducede1
- Comparator
- N100e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Compared with N100, N reduction alone had no significant impact on the number of tillers and aboveground biomass of rice, exceptfor N60 which slightly reduced grain yield”
Claim · model-written summary
Biochar incorporation tended to give higher tillers, aboveground biomass and grain yield of rice than N reduction alone.
- Taxon
- riceOryza sativae2
- Treatment
- biochar incorporatione2
- Outcome
- tillers, aboveground biomass, and grain yielde2
- Direction
- highere2
- Qualifier
- tendede2
- Comparator
- N reduction alonee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“biochar incorporation tended to obtain higher tillers, aboveground biomass, and grain yield of rice compared with N reduction alone”
Claim · model-written summary
Biochar contributed an average of 5.8% to rice grain yield on the basis of N80.
- Taxon
- riceOryza sativae1
- Treatment
- biochare3
- Outcome
- grain yielde3
- Direction
- increaseinferrede3
- Value
- 5.8%e3
- Qualifier
- on the basis of N80 and N60e3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“biochar incorporation tended to obtain higher tillers, aboveground biomass, and grain yield of rice compared with N reduction alone”
e3“The average contribution of biochar to grain yield on the basis of N80 and N60 were 5.8% and 7.7%, respectively”
Claim · model-written summary
Biochar contributed an average of 7.7% to rice grain yield on the basis of N60.
- Taxon
- riceOryza sativae1
- Treatment
- biochare3
- Outcome
- grain yielde3
- Direction
- increaseinferrede3
- Value
- 7.7%e3
- Qualifier
- on the basis of N80 and N60e3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“biochar incorporation tended to obtain higher tillers, aboveground biomass, and grain yield of rice compared with N reduction alone”
e3“The average contribution of biochar to grain yield on the basis of N80 and N60 were 5.8% and 7.7%, respectively”
Claim · model-written summary
Biochar incorporation further improved agronomic N efficiency of rice by 54.5–309.4% over N100.
- Taxon
- riceOryza sativae1
- Treatment
- biochar incorporatione4
- Outcome
- agronomic N efficiencye4
- Direction
- improvede4
- Value
- 54.5–309.4%e4
- Comparator
- N100e4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“biochar incorporation tended to obtain higher tillers, aboveground biomass, and grain yield of rice compared with N reduction alone”
e4“biochar incorporation further improved the agronomic N efficiency (54.5–309.4% over N100) and apparent N recovery (25.7–150.5% over N100)”
Claim · model-written summary
Biochar incorporation further improved apparent N recovery of rice by 25.7–150.5% over N100.
- Taxon
- riceOryza sativae1
- Treatment
- biochar incorporatione4
- Outcome
- apparent N recoverye4
- Direction
- improvede4
- Value
- 25.7–150.5%e4
- Comparator
- N100e4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“biochar incorporation tended to obtain higher tillers, aboveground biomass, and grain yield of rice compared with N reduction alone”
e4“biochar incorporation further improved the agronomic N efficiency (54.5–309.4% over N100) and apparent N recovery (25.7–150.5% over N100)”
Claim · model-written summary
Biochar application maintained the N nutrition level of rice.
- Taxon
- riceOryza sativae5
- Treatment
- biochar applicatione5
- Outcome
- N nutrition levele5
- Direction
- maintaine5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“biochar application could not only maintain N nutrition level of rice, but also improve soil fertility mainly by increasing soil pH and organic matter”
Claim · model-written summary
Biochar application improved soil fertility mainly by increasing soil pH and organic matter.
- Taxon
- riceOryza sativae5
- Treatment
- biochar applicatione5
- Outcome
- soil pH and organic mattere5
- Direction
- increasinge5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“biochar application could not only maintain N nutrition level of rice, but also improve soil fertility mainly by increasing soil pH and organic matter”
Claim · model-written summary
Integrated application of mineral N fertilizer and biochar is recommended as a feasible nutrient management measure for rice in paddy ecosystems.
- Taxon
- riceOryza sativae6
- Outcome
- integrated application of mineral N fertilizer and biochare6
- Setting
- paddy ecosysteme6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“integrated application of mineral N fertilizer and biochar is a feasible nutrient management measure to increase rice yield and soil fertility, and improve N use efficiency in paddy ecosystem”
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