Abstract
Abstract Acidity constraints in Oxisols of the Amazon may entail both Al toxicity and Ca deficiency. A field study was conducted in a Xanthic Hapludox near Manaus, Brazil, to evaluate lime and Ca requirements for corn ( Zea mays L.), cowpea ( Vigna unguiculata L.), soybean [ Glycine max (L.) Merr.], and peanut ( Arachis hypogea L.) during five consecutive years. Calcitic lime was applied once at rates of 0, 0.6, 1.2, 2.3, and 4.6 t of CaCO 3 equivalent per hectare. The effects of 1 t ha −1 of gypsum, applied to four crops, were evaluated with lime rates of 0, 1.2 and 2.3 t ha −1 . During the two initial years, maximum yields of corn and soybean occurred with 1.2 t of lime ha −1 . In subsequent years, maximum corn yields occurred to 4.6 t of lime ha −1 . Liming only increased cowpea yields in the third year. Peanut yields increased with liming to the highest lime rate in the fourth and fifth year. Gypsum increased yields for all crops to which it was applied. When averaged across time gypsum increased exchangeable Ca and reduced exchangeable Al by 0.41 and 0.20 cmol c kg −1 , respectively. Increased peanut shelling percent and peanut and cowpea leaf Ca concentrations with lime, gypsum, or both were indicative of improved soil Ca supply. Maximum corn and soybean yields occurred at 27% Al saturation, whereas the critical level for peanut was 54%. Regressions of relative yield for all lime and gypsum treatments on the exchangeable Ca:Al ratio gave R 2 values equal to those achieved with Al or Ca saturation. Critical Ca:Al ratio values would provide a useful index to ensure that lime recommendations based on Al saturation provide an adequate Ca supply.
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Claims 16
Claim · model-written summary
Maximum corn yield occurred with 1.2 t of lime per hectare in the two initial years.
- Taxon
- corn
Zea mays subsp. mayse0 - Treatment
- 1.2 t of lime ha −1e0
- Outcome
- yieldse0
- Direction
- maximume0
- Qualifier
- During the two initial yearse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“During the two initial years, maximum yields of corn and soybean occurred with 1.2 t of lime ha −1”
Claim · model-written summary
Maximum soybean yield occurred with 1.2 t of lime per hectare in the two initial years.
- Taxon
- soybean
Glycine maxe0 - Treatment
- 1.2 t of lime ha −1e0
- Outcome
- yieldse0
- Direction
- maximume0
- Qualifier
- During the two initial yearse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“During the two initial years, maximum yields of corn and soybean occurred with 1.2 t of lime ha −1”
Claim · model-written summary
Maximum corn yields occurred with 4.6 t of lime per hectare in subsequent years.
- Taxon
- cornZea mays subsp. mayse1
- Treatment
- 4.6 t of lime ha −1e1
- Outcome
- corn yieldse1
- Direction
- maximume1
- Qualifier
- In subsequent yearse1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“In subsequent years, maximum corn yields occurred to 4.6 t of lime ha −1”
Claim · model-written summary
Liming increased cowpea yields only in the third year.
- Taxon
- cowpea
Vigna unguiculatae2 - Treatment
- Liminge2
- Outcome
- cowpea yieldse2
- Direction
- increasede2
- Qualifier
- in the third yeare2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“Liming only increased cowpea yields in the third year”
Claim · model-written summary
Peanut yields increased with liming to the highest lime rate in the fourth and fifth year.
- Taxon
- Peanut
Arachis hypogaeae3 - Treatment
- liming to the highest lime ratee3
- Outcome
- Peanut yieldse3
- Direction
- increasede3
- Qualifier
- in the fourth and fifth yeare3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“Peanut yields increased with liming to the highest lime rate in the fourth and fifth year”
Claim · model-written summary
Gypsum increased yields of all crops to which it was applied.
Not reportedComparator
Verbatim
e4“Gypsum increased yields for all crops to which it was applied”
Claim · model-written summary
Gypsum increased exchangeable Ca by 0.41 cmol c kg −1 when averaged across time.
- Taxon
- cropse6
- Treatment
- gypsume5
- Outcome
- exchangeable Cae5
- Direction
- increasede5
- Value
- 0.41e5
- Qualifier
- When averaged across timee5
Not reportedComparator
Verbatim
e5“When averaged across time gypsum increased exchangeable Ca and reduced exchangeable Al by 0.41 and 0.20 cmol c kg −1”
e6“applied to four crops”
Claim · model-written summary
Gypsum reduced exchangeable Al by 0.20 cmol c kg −1 when averaged across time.
- Taxon
- cropse6
- Treatment
- gypsume5
- Outcome
- exchangeable Ale5
- Direction
- reducede5
- Value
- 0.20 cmol c kg −1e5
- Qualifier
- When averaged across timee5
Not reportedComparator
Verbatim
e5“When averaged across time gypsum increased exchangeable Ca and reduced exchangeable Al by 0.41 and 0.20 cmol c kg −1”
e6“applied to four crops”
Claim · model-written summary
Lime, gypsum or both increased peanut shelling percent, indicating improved soil Ca supply.
- Taxon
- peanutArachis hypogaeae7
- Treatment
- lime, gypsum, or bothe7
- Outcome
- peanut shelling percente7
- Direction
- Increasede7
- Qualifier
- indicative of improved soil Ca supplye7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“Increased peanut shelling percent and peanut and cowpea leaf Ca concentrations with lime, gypsum, or both were indicative of improved soil Ca supply”
Claim · model-written summary
Lime, gypsum or both increased peanut leaf Ca concentrations, indicating improved soil Ca supply.
- Taxon
- peanutArachis hypogaeae7
- Treatment
- lime, gypsum, or bothe7
- Outcome
- leaf Ca concentrationse7
- Direction
- Increasede7
- Qualifier
- indicative of improved soil Ca supplye7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“Increased peanut shelling percent and peanut and cowpea leaf Ca concentrations with lime, gypsum, or both were indicative of improved soil Ca supply”
Claim · model-written summary
Lime, gypsum or both increased cowpea leaf Ca concentrations, indicating improved soil Ca supply.
- Taxon
- cowpeaVigna unguiculatae7
- Treatment
- lime, gypsum, or bothe7
- Outcome
- leaf Ca concentrationse7
- Direction
- Increasede7
- Qualifier
- indicative of improved soil Ca supplye7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“Increased peanut shelling percent and peanut and cowpea leaf Ca concentrations with lime, gypsum, or both were indicative of improved soil Ca supply”
Claim · model-written summary
Maximum corn yield occurred at 27% Al saturation.
- Taxon
- cornZea mays subsp. mayse7
- Outcome
- yieldse7
- Direction
- Maximume7
- Value
- 27%e7
- Qualifier
- at 27% Al saturatione7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“Maximum corn and soybean yields occurred at 27% Al saturation, whereas the critical level for peanut was 54%”
Claim · model-written summary
Maximum soybean yield occurred at 27% Al saturation.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“Maximum corn and soybean yields occurred at 27% Al saturation, whereas the critical level for peanut was 54%”
Claim · model-written summary
The critical Al saturation level for peanut was 54%.
- Taxon
- peanutArachis hypogaeae7
- Outcome
- critical levele7
- Value
- 54%e7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“Maximum corn and soybean yields occurred at 27% Al saturation, whereas the critical level for peanut was 54%”
Claim · model-written summary
Relative yield regressed on the exchangeable Ca:Al ratio gave R 2 values equal to those for Al or Ca saturation.
Not reportedDirection
Verbatim
e6“applied to four crops”
e7“Regressions of relative yield for all lime and gypsum treatments on the exchangeable Ca:Al ratio gave R 2 values equal to those achieved with Al or Ca saturation”
Claim · model-written summary
Critical Ca:Al ratio values would give a useful index to ensure adequate Ca supply in lime recommendations based on Al saturation.
Verbatim
e6“applied to four crops”
e7“Critical Ca:Al ratio values would provide a useful index to ensure that lime recommendations based on Al saturation provide an adequate Ca supply”
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lime · nutrient: content · Arachis hypogaea (peanut)Results differ
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- no effect
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184 papers in the same direction as this paper · 31 in the opposite direction · 3 reporting no difference from an alternative
- no effect
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See all 219 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.