Paper · 2021 · Biochar

Effect of pyrolysis temperature on Si release of alkali-enhanced Si-rich biochar and plant response

Meng Wang; Negar D. Tafti; Jim J. Wang; et al.

6
claims
9
verbatim quotes
31
citations
2
research areas
✓
Open access · cc-by

Abstract

Abstract Recent studies have shown that silicon (Si) dissolution from biochar may be influenced by the pyrolysis temperature. In addition, the enhancement of biochar by treatment with alkali has been proposed to produce a Si source that can be used for environmentally friendly plant disease control. In this study, biochars from rice straw and rice husk pretreated with KOH, CaO and K 2 CO 3 and then pyrolyzed at 350, 450 and 550 °C were prepared to evaluate the effects of pyrolysis temperature on Si release and plant uptake from alkali-enhanced Si-rich biochar. Extractable Si and dissolution Si from the prepared biochars were assessed by different short-term chemical methods and long-term (30-day) release in dilute acid and neutral salt solutions, respectively, along with a rice potting experiment in greenhouse. For both rice straw- and husk-derived alkali-enhanced biochars (RS-10KB and HS-10K2B, respectively), increasing the pyrolysis temperature from 350 to 550 °C generally had the highest extractable Si and increased Si content extracted by 5-day sodium carbonate and ammonium nitrate (5dSCAN) designated for fertilizer Si by 61–142%, whereas non-enhanced biochars had more extractable Si at 350 °C. The alkali-enhanced biochars produced at 550 °C pyrolysis temperature also released 82–172% and 27–79% more Si than that of 350 °C produced biochar in unbuffered weak acid and neutral salt solutions, respectively, over 30 days. In addition, alkali-enhanced biochars, especially that derived from rice husk at 550 °C facilitated 6–21% greater Si uptake by rice and 44–101% higher rice grain yields than lower temperature biochars, non-enhanced biochars, or conventional Si fertilizers (wollastonite and silicate calcium slag). Overall, this study demonstrated that 550 °C is more efficient than lower pyrolysis temperature for preparing alkali-enhanced biochar to improve Si release for plant growth.

Abstract from the paper’s OpenAlex record; open copy licensed cc-by. 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 6

Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Higher pyrolysis temperature raised extractable silicon of alkali-enhanced rice biochars, with 61–142% more fertilizer silicon extract.

Treatment
increasing the pyrolysis temperature from 350 to 550 °Ce0
Outcome
Si content extracted by 5-day sodium carbonate and ammonium nitrate (5dSCAN)e0
Direction
increasede0
Value
61–142%e0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“For both rice straw- and husk-derived alkali-enhanced biochars (RS-10KB and HS-10K2B, respectively), increasing the pyrolysis temperature from 350 to 550 °C generally had the highest extractable Si and increased Si content extracted by 5-day sodium carbonate and ammonium nitrate (5dSCAN) designated for fertilizer Si by 61–142%”

✓ located verbatim in the source · abstract, characters 823–1151 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

Non-enhanced biochars had more extractable silicon at 350 °C.

Taxon
plantt0
Treatment
350 °Ce0
Outcome
extractable Sie0
Direction
moree0

Verbatim

e0

“non-enhanced biochars had more extractable Si at 350 °C”

✓ located verbatim in the source · abstract, characters 1161–1216 · show in text ↑
t0

“plant response”

✓ located verbatim in the source · title, characters 85–99 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Alkali-enhanced biochar made at 550 °C released 82–172% more silicon in weak acid than 350 °C biochar.

Taxon
plantt0
Treatment
550 °C pyrolysis temperaturee0
Outcome
Sie0
Direction
moree0
Value
82–172%e0
Qualifier
unbuffered weak acide0
Comparator
350 °C produced biochare0

Verbatim

e0

“alkali-enhanced biochars produced at 550 °C pyrolysis temperature also released 82–172% and 27–79% more Si than that of 350 °C produced biochar in unbuffered weak acid and neutral salt solutions, respectively, over 30 days”

✓ located verbatim in the source · abstract, characters 1222–1444 · show in text ↑
t0

“plant response”

✓ located verbatim in the source · title, characters 85–99 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Alkali-enhanced biochar made at 550 °C released 27–79% more silicon in neutral salt solution than 350 °C biochar.

Taxon
plantt0
Treatment
550 °C pyrolysis temperaturee0
Outcome
Sie0
Direction
moree0
Value
27–79%e0
Qualifier
neutral salt solutionse0
Comparator
350 °C produced biochare0

Verbatim

e0

“alkali-enhanced biochars produced at 550 °C pyrolysis temperature also released 82–172% and 27–79% more Si than that of 350 °C produced biochar in unbuffered weak acid and neutral salt solutions, respectively, over 30 days”

✓ located verbatim in the source · abstract, characters 1222–1444 · show in text ↑
t0

“plant response”

✓ located verbatim in the source · title, characters 85–99 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Alkali-enhanced biochars increased rice silicon uptake by 6–21% relative to the listed comparators.

Treatment
alkali-enhanced biocharse0
Outcome
Si uptakee0
Direction
greatere0
Value
6–21%e0
Comparator
lower temperature biochars, non-enhanced biochars, or conventional Si fertilizerse0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“alkali-enhanced biochars, especially that derived from rice husk at 550 °C facilitated 6–21% greater Si uptake by rice and 44–101% higher rice grain yields than lower temperature biochars, non-enhanced biochars, or conventional Si fertilizers (wollastonite and silicate calcium slag)”

✓ located verbatim in the source · abstract, characters 1459–1742 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Alkali-enhanced biochars increased rice grain yield by 44–101% relative to the listed comparators.

Treatment
alkali-enhanced biocharse0
Outcome
rice grain yieldse0
Direction
highere0
Value
44–101%e0
Comparator
lower temperature biochars, non-enhanced biochars, or conventional Si fertilizerse0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“alkali-enhanced biochars, especially that derived from rice husk at 550 °C facilitated 6–21% greater Si uptake by rice and 44–101% higher rice grain yields than lower temperature biochars, non-enhanced biochars, or conventional Si fertilizers (wollastonite and silicate calcium slag)”

✓ located verbatim in the source · abstract, characters 1459–1742 · show in text ↑

alkalinity · yield · Oryza sativa (rice)Positive and negative results

5 papers: 2 positive, 3 negative or no effect

1 paper in the same direction as this paper · 3 in the opposite direction

  1. negative
  2. negative
  3. negative

1 paper more in this group

See all 5 papers →

alkalinity · nutrient: content · Oryza sativa (rice)Positive and negative results

10 papers: 4 positive, 6 negative or no effect

3 papers in the same direction as this paper · 5 in the opposite direction · 1 reporting no difference from an alternative

  1. negative
  2. negative
  3. negative

6 papers more in this group

See all 10 papers →

biochar · nutrient: content · Oryza sativa (rice)Positive and negative results

86 papers: 81 positive, 5 negative or no effect

80 papers in the same direction as this paper · 4 in the opposite direction · 1 reporting no difference from an alternative

  1. positive
  2. negative
  3. no effect

82 papers more in this group

See all 86 papers →

biochar · yield · Oryza sativa (rice)Positive and negative results

147 papers: 135 positive, 12 negative or no effect

134 papers in the same direction as this paper · 12 in the opposite direction

  1. negative
  2. no effect
  3. no effect

143 papers more in this group

See all 147 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.