Abstract
“4 per 1000 Initiative” launched at COP21 has strongly recommended that increasing soil organic carbon (SOC) is a global imperative. However, the strategies to improve agricultural soil functioning and health by an increase in soil C have been poorly addressed. In a rice farm trail, topsoil samples were collected in 2015 respectively in a field amended with biochar (BA) (equivalent to 10 t ha−1) in 2009 and an adjacent field with no biochar (NB). Soil aggregation, biochemical activities and microbial communities of the samples were analyzed with microscopic, micro-biochemical and molecular assays respectively. Compared to NB field, SOC storage increased by 45%, total and available nitrogen pool enhanced by approximately 30% while the bulk density decreased and soil pH unchanged in BA field. A 25% increase in mean weight diameter of water stable aggregates was observed in the BA compared to NB field. Correspondingly, microbial biomass nitrogen and enzyme activities in BA field was enhanced both by approximately 30% compared to NB field. Furthermore, with community structure altered, a moderate (32%) increase in total bacterial abundance and a significant decrease in microbial abundance of amino acid metabolism and fungal pathotrophs were observed in BA field compared to NB field. This could link to the higher (10%) grain yield with lower yield inter-annual variability in BA field compared to NB field, reported previously. All these changes clearly demonstrated a legacy of paddy soil health improvement over years following one time biochar amendment. Overall, addition of biochar to the clayey nutrient rich paddy soil could sustain an increase in SOC, soil aggregation and soil health functioning, with positive changes in microbial community over years. Thus, carbon increase as per required by the “4 per 1000 Initiative” could be a mechanistic driver to enhance soil fertility and improve soil-(plant) health for ensuring food production in world rice agriculture facing land degradation and climate change impacts, which could be assisted by biochar from crop residue in an approach of circular economy.
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Claims 10
Claim · model-written summary
Biochar amendment increased soil organic carbon storage by 45% relative to the unamended field.
- Taxon
- rice
Oryza sativat0 - Treatment
- amended with biochar (BA)e1
- Outcome
- SOC storagee2
- Direction
- increasede2
- Value
- 45%e2
- Comparator
- NB fielde2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“A rice farm trial”
e1“in a field amended with biochar (BA) (equivalent to 10 t ha−1) in 2009 and an adjacent field with no biochar (NB)”
e2“Compared to NB field, SOC storage increased by 45%, total and available nitrogen pool enhanced by approximately 30% while the bulk density decreased and soil pH unchanged in BA field”
Claim · model-written summary
Biochar amendment enhanced total and available nitrogen pool by approximately 30% relative to the unamended field.
- Taxon
- riceOryza sativat0
- Treatment
- amended with biochar (BA)e1
- Outcome
- total and available nitrogen poole2
- Direction
- enhancede2
- Value
- approximately 30%e2
- Comparator
- NB fielde2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“A rice farm trial”
e1“in a field amended with biochar (BA) (equivalent to 10 t ha−1) in 2009 and an adjacent field with no biochar (NB)”
e2“Compared to NB field, SOC storage increased by 45%, total and available nitrogen pool enhanced by approximately 30% while the bulk density decreased and soil pH unchanged in BA field”
Claim · model-written summary
Biochar amendment decreased soil bulk density relative to the unamended field.
- Taxon
- riceOryza sativat0
- Treatment
- amended with biochar (BA)e1
- Outcome
- bulk densitye2
- Direction
- decreasede2
- Comparator
- NB fielde2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“A rice farm trial”
e1“in a field amended with biochar (BA) (equivalent to 10 t ha−1) in 2009 and an adjacent field with no biochar (NB)”
e2“Compared to NB field, SOC storage increased by 45%, total and available nitrogen pool enhanced by approximately 30% while the bulk density decreased and soil pH unchanged in BA field”
Claim · model-written summary
Biochar amendment left soil pH unchanged relative to the unamended field.
- Taxon
- riceOryza sativat0
- Treatment
- amended with biochar (BA)e1
- Outcome
- soil pHe2
- Direction
- unchangede2
- Comparator
- NB fielde2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“A rice farm trial”
e1“in a field amended with biochar (BA) (equivalent to 10 t ha−1) in 2009 and an adjacent field with no biochar (NB)”
e2“Compared to NB field, SOC storage increased by 45%, total and available nitrogen pool enhanced by approximately 30% while the bulk density decreased and soil pH unchanged in BA field”
Claim · model-written summary
Biochar amendment increased the mean weight diameter of water-stable aggregates by 25% relative to the unamended field.
- Taxon
- riceOryza sativat0
- Treatment
- amended with biochar (BA)e1
- Outcome
- mean weight diameter of water stable aggregatese3
- Direction
- increasee3
- Value
- 25%e3
- Comparator
- NB fielde3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“A rice farm trial”
e1“in a field amended with biochar (BA) (equivalent to 10 t ha−1) in 2009 and an adjacent field with no biochar (NB)”
e3“A 25% increase in mean weight diameter of water stable aggregates was observed in the BA compared to NB field”
Claim · model-written summary
Biochar amendment enhanced microbial biomass nitrogen and enzyme activities by approximately 30% relative to the unamended field.
- Taxon
- riceOryza sativat0
- Treatment
- amended with biochar (BA)e1
- Outcome
- microbial biomass nitrogen and enzyme activitiese4
- Direction
- enhancede4
- Value
- approximately 30%e4
- Comparator
- NB fielde4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“A rice farm trial”
e1“in a field amended with biochar (BA) (equivalent to 10 t ha−1) in 2009 and an adjacent field with no biochar (NB)”
e4“microbial biomass nitrogen and enzyme activities in BA field was enhanced both by approximately 30% compared to NB field”
Claim · model-written summary
Biochar amendment increased total bacterial abundance by 32% relative to the unamended field, with community structure altered.
- Taxon
- riceOryza sativat0
- Treatment
- amended with biochar (BA)e1
- Outcome
- total bacterial abundancee5
- Direction
- increasee5
- Value
- 32%e5
- Qualifier
- community structure alterede5
- Comparator
- NB fielde5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“A rice farm trial”
e1“in a field amended with biochar (BA) (equivalent to 10 t ha−1) in 2009 and an adjacent field with no biochar (NB)”
e5“with community structure altered, a moderate (32%) increase in total bacterial abundance and a significant decrease in microbial abundance of amino acid metabolism and fungal pathotrophs were observed in BA field compared to NB field”
Claim · model-written summary
Biochar amendment significantly decreased microbial abundance of amino acid metabolism and fungal pathotrophs relative to the unamended field.
- Taxon
- riceOryza sativat0
- Treatment
- amended with biochar (BA)e1
- Outcome
- microbial abundance of amino acid metabolism and fungal pathotrophse5
- Direction
- significant decreasee5
- Comparator
- NB fielde5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“A rice farm trial”
e1“in a field amended with biochar (BA) (equivalent to 10 t ha−1) in 2009 and an adjacent field with no biochar (NB)”
e5“with community structure altered, a moderate (32%) increase in total bacterial abundance and a significant decrease in microbial abundance of amino acid metabolism and fungal pathotrophs were observed in BA field compared to NB field”
Claim · model-written summary
Biochar amendment was linked to a higher (10%) rice grain yield relative to the unamended field, as reported previously.
- Taxon
- riceOryza sativat0
- Treatment
- amended with biochar (BA)e1
- Outcome
- grain yielde6
- Direction
- highere6
- Value
- 10%e6
- Comparator
- NB fielde6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“A rice farm trial”
e1“in a field amended with biochar (BA) (equivalent to 10 t ha−1) in 2009 and an adjacent field with no biochar (NB)”
e6“This could link to the higher (10%) grain yield with lower yield inter-annual variability in BA field compared to NB field, reported previously”
Claim · model-written summary
Biochar amendment was linked to lower rice yield inter-annual variability relative to the unamended field, as reported previously.
- Taxon
- riceOryza sativat0
- Treatment
- amended with biochar (BA)e1
- Outcome
- yield inter-annual variabilitye6
- Direction
- lowere6
- Comparator
- NB fielde6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“A rice farm trial”
e1“in a field amended with biochar (BA) (equivalent to 10 t ha−1) in 2009 and an adjacent field with no biochar (NB)”
e6“This could link to the higher (10%) grain yield with lower yield inter-annual variability in BA field compared to NB field, reported previously”
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