Abstract
Abstract It is essential to increase the pH of tropical soils in order to reduce acidity and promote soil and crop productivity. Therefore, experiments were carried out in 2020 and 2021 to assess the impacts of biochar and lime on the chemical properties, growth, nodulation, and yield of cowpea ( Vigna unguiculata ). The study involved various levels of lime (CaCO 3 ) and wood biochar (ranging from 0 to 10 t ha −1 ), organized in a factorial combination. The treatments were arranged in a randomized complete block design and replicated three times. The application of lime and biochar, either separately or in combination, led to improvements in soil chemical properties such as pH, nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sodium (Na), magnesium (Mg), and cation exchange capacity (CEC), as well as enhancements in the growth, nodulation, and yield of cowpea when compared to the control. Lime and biochar alone and combined reduced exchangeable acidity (Al + H) relative to the control. Cowpea yield increased with lime rate up to a point, but then decreases. The highest cowpea yield is achieved at a lime rate of 2.5 t ha −1 , whereas cowpea yield increased as the Biochar rate increased from 0 up to 10 t ha −1 . There was a significant correlation between pH and cowpea pod weight in both years (2020 and 2021). The R values were − 0.615 and − 0.444 for years 2020 and year 2021 respectively at P < 0.05. At higher lime levels combined with biochar, there were considerable reductions in cowpea yield, and this decrease can be attributed to unfavorable soil pH conditions. Relative to 2.5 t ha −1 lime + 5 t ha −1 biochar, 10 t ha −1 lime + 10 t ha −1 biochar, reduced cowpea grain yield by 853% in 2020 and 845% in 2021. Since there were no significant differences between the effects of 2.5 t ha −1 lime + 5 t ha −1 biochar, 2.5 t ha −1 lime + 7.5 t ha −1 biochar, and 2.5 t ha −1 lime + 10 t ha −1 biochar applications on cowpea yield, therefore to prevent waste of Biochar, 2.5 t ha −1 lime + 5 t ha −1 biochar is recommended for production of cowpea.
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Claims 11
Claim · model-written summary
Lime and biochar, separately or combined, improved soil chemical properties.
- Taxon
- cowpea
Vigna unguiculatae0 - Treatment
- The application of lime and biochare1
- Outcome
- soil chemical propertiese1
- Direction
- improvementse1
- Comparator
- controle2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“yield of cowpea ( Vigna unguiculata )”
e1“The application of lime and biochar, either separately or in combination, led to improvements in soil chemical properties”
e2“as well as enhancements in the growth, nodulation, and yield of cowpea when compared to the control”
Claim · model-written summary
Lime and biochar improved growth, nodulation and yield of cowpea compared with the control.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- The application of lime and biochare1
- Outcome
- growth, nodulation, and yielde2
- Direction
- enhancementse2
- Comparator
- controle2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“yield of cowpea ( Vigna unguiculata )”
e1“The application of lime and biochar, either separately or in combination, led to improvements in soil chemical properties”
e2“as well as enhancements in the growth, nodulation, and yield of cowpea when compared to the control”
Claim · model-written summary
Lime and biochar alone and combined reduced exchangeable acidity (Al + H) relative to the control.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- Lime and biochar alone and combinede3
- Outcome
- exchangeable acidity (Al + H)e3
- Direction
- reducede3
- Comparator
- controle3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“yield of cowpea ( Vigna unguiculata )”
e3“Lime and biochar alone and combined reduced exchangeable acidity (Al + H) relative to the control”
Claim · model-written summary
Cowpea yield increased with lime rate up to a point.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- lime ratee4
- Outcome
- Cowpea yielde4
- Direction
- increasede4
- Qualifier
- up to a pointe4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“yield of cowpea ( Vigna unguiculata )”
e4“Cowpea yield increased with lime rate up to a point, but then decreases”
Claim · model-written summary
At higher lime levels combined with biochar, cowpea yield was considerably reduced, which the authors attribute to unfavorable soil pH.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- higher lime levels combined with biochare5
- Outcome
- cowpea yielde5
- Direction
- reductionse5
- Qualifier
- unfavorable soil pH conditionse5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“yield of cowpea ( Vigna unguiculata )”
e5“At higher lime levels combined with biochar, there were considerable reductions in cowpea yield, and this decrease can be attributed to unfavorable soil pH conditions”
Claim · model-written summary
The highest cowpea yield was achieved at a lime rate of 2.5 t ha −1.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- lime rate of 2.5 t ha −1e6
- Outcome
- cowpea yielde6
- Direction
- higheste6
- Value
- 2.5 t ha −1e6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“yield of cowpea ( Vigna unguiculata )”
e6“The highest cowpea yield is achieved at a lime rate of 2.5 t ha −1”
Claim · model-written summary
Cowpea yield increased as biochar rate rose from 0 up to 10 t ha −1.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- Biochar ratee7
- Outcome
- cowpea yielde7
- Direction
- increasede7
- Value
- 0 up to 10 t ha −1e7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“yield of cowpea ( Vigna unguiculata )”
e7“whereas cowpea yield increased as the Biochar rate increased from 0 up to 10 t ha −1”
Claim · model-written summary
Pod weight was significantly correlated with pH in both years (R = −0.615 and −0.444 at P < 0.05).
- Taxon
- cowpeaVigna unguiculatae0
- Outcome
- pod weighte1
- Value
- − 0.615 and − 0.444e2
- Setting
- both years (2020 and 2021)e1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“yield of cowpea ( Vigna unguiculata )”
e1“There was a significant correlation between pH and cowpea pod weight in both years (2020 and 2021)”
e2“The R values were − 0.615 and − 0.444 for years 2020 and year 2021 respectively at P < 0.05”
Claim · model-written summary
Lime 10 t ha −1 with biochar 10 t ha −1 reduced cowpea grain yield by 853% in 2020 and 845% in 2021 relative to 2.5 t ha −1 lime with 5 t ha −1 biochar.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- 10 t ha −1 lime + 10 t ha −1 biochare1
- Outcome
- grain yielde1
- Direction
- reducede1
- Value
- 853% in 2020 and 845% in 2021e1
- Comparator
- 2.5 t ha −1 lime + 5 t ha −1 biochare1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“yield of cowpea ( Vigna unguiculata )”
e1“Relative to 2.5 t ha −1 lime + 5 t ha −1 biochar, 10 t ha −1 lime + 10 t ha −1 biochar, reduced cowpea grain yield by 853% in 2020 and 845% in 2021”
Claim · model-written summary
No significant difference in cowpea yield among 2.5 t ha −1 lime combined with 5, 7.5 or 10 t ha −1 biochar.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- 2.5 t ha −1 lime + 5 t ha −1 biochare1
- Outcome
- cowpea yielde1
- Direction
- no significant differencese1
- Comparator
- 2.5 t ha −1 lime + 7.5 t ha −1 biochare1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“yield of cowpea ( Vigna unguiculata )”
e1“Since there were no significant differences between the effects of 2.5 t ha −1 lime + 5 t ha −1 biochar, 2.5 t ha −1 lime + 7.5 t ha −1 biochar, and 2.5 t ha −1 lime + 10 t ha −1 biochar applications on cowpea yield”
Claim · model-written summary
2.5 t ha −1 lime with 5 t ha −1 biochar is recommended for cowpea production.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- 2.5 t ha −1 lime + 5 t ha −1 biochare1
- Outcome
- production of cowpeae1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“yield of cowpea ( Vigna unguiculata )”
e1“2.5 t ha −1 lime + 5 t ha −1 biochar is recommended for production of cowpea”
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See all 7 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.