Abstract
Abstract Application of phosphate rock is of interest to low‐input systems in the humid tropics, because phosphate rock is less expensive than ordinary superphosphate and releases P quickly in acid soils. However, the lack of incorporation in zero‐tillage systems may result in low availability of surface‐applied P. This study was directed toward determining the effects of these two P sources under no‐till and rotovation tillage systems on crop production in a fine‐loamy siliceous, isohyperthermic Typic Paleudult of Yurimaguas, Peru. A rotation of Al‐tolerant cultivars of rice ( Oryza sativa L.)‐rice‐cowpea ( Vigna unguiculata ) was followed for seven consecutive harvests. Grain yields increased with rotovation in the first crop, were not affected by tillage methods during the second and third crops, but decreased with rotovation from the third to the seventh crops. Sechura phosphate rock at a soil pH of 4.5 was as effective as superphosphate in supplying available P. A total of 13.9 Mg ha −1 of rice and 2.5 Mg ha −1 of cowpea grain was produced in seven harvests in newly cleared fields without lime or P application. There were significant responses to P fertilization in one rice crop and in both cowpea crops. On the average, however, rice yield did not respond to P. A single application of 22 kg P ha‐' was sufficient to produce 85% of the maximum yield of cowpea for 2 yr. The results with cowpea indicate that broadcast phosphate rock is a good source of P for low‐input systems on acid soils where acid‐tolerant cultivars are used.
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Claims 11
Claim · model-written summary
Rotovation increased first-crop grain yield.
- Taxon
- rice
Oryza sativae7 - Treatment
- rotovatione0
- Outcome
- Grain yieldse0
- Direction
- increasede0
- Qualifier
- first crope0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grain yields increased with rotovation in the first crop, were not affected by tillage methods during the second and third crops, but decreased with rotovation from the third to the seventh crops.”
e7“rice ( Oryza sativa L.)‐rice‐cowpea ( Vigna unguiculata )”
Claim · model-written summary
Tillage methods did not affect grain yields in the second and third crops.
- Taxon
- riceOryza sativae7
- Treatment
- tillage methodse0
- Outcome
- grain yieldse0
- Direction
- not affectede0
- Qualifier
- second and third cropse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grain yields increased with rotovation in the first crop, were not affected by tillage methods during the second and third crops, but decreased with rotovation from the third to the seventh crops.”
e7“rice ( Oryza sativa L.)‐rice‐cowpea ( Vigna unguiculata )”
Claim · model-written summary
Rotovation decreased grain yields from the third to the seventh crops.
- Taxon
- cowpea
Vigna unguiculatae7 - Treatment
- rotovatione0
- Outcome
- grain yieldse0
- Direction
- decreasede0
- Qualifier
- third to the seventh cropse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grain yields increased with rotovation in the first crop, were not affected by tillage methods during the second and third crops, but decreased with rotovation from the third to the seventh crops.”
e7“rice ( Oryza sativa L.)‐rice‐cowpea ( Vigna unguiculata )”
Claim · model-written summary
At soil pH 4.5, Sechura phosphate rock supplied available P as effectively as superphosphate.
- Treatment
- Sechura phosphate rocke0
- Outcome
- available Pe0
- Direction
- as effectivee0
- Qualifier
- soil pH of 4.5e0
- Comparator
- superphosphatee0
Not reportedTaxon
Verbatim
e0“Sechura phosphate rock at a soil pH of 4.5 was as effective as superphosphate in supplying available P.”
Claim · model-written summary
rice produced 13.9 Mg ha −1 over seven harvests without lime or P application.
- Taxon
- riceOryza sativae0
- Outcome
- ricee0
- Value
- 13.9 Mg ha −1e0
- Qualifier
- seven harvests in newly cleared fields without lime or P applicatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A total of 13.9 Mg ha −1 of rice and 2.5 Mg ha −1 of cowpea grain was produced in seven harvests in newly cleared fields without lime or P application.”
Claim · model-written summary
cowpea produced 2.5 Mg ha −1 over seven harvests without lime or P application.
- Taxon
- cowpeaVigna unguiculatae0
- Outcome
- cowpea graine0
- Value
- 2.5 Mg ha −1e0
- Qualifier
- seven harvests in newly cleared fields without lime or P applicatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A total of 13.9 Mg ha −1 of rice and 2.5 Mg ha −1 of cowpea grain was produced in seven harvests in newly cleared fields without lime or P application.”
Claim · model-written summary
rice responded significantly to P fertilization in one rice crop.
- Taxon
- riceOryza sativae0
- Treatment
- P fertilizatione0
- Outcome
- responsese0
- Qualifier
- one rice crope0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There were significant responses to P fertilization in one rice crop and in both cowpea crops.”
Claim · model-written summary
cowpea responded significantly to P fertilization in both cowpea crops.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- P fertilizatione0
- Outcome
- responsese0
- Qualifier
- both cowpea cropse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There were significant responses to P fertilization in one rice crop and in both cowpea crops.”
Claim · model-written summary
Average rice yield did not respond to P.
- Taxon
- riceOryza sativae0
- Treatment
- Pe0
- Outcome
- rice yielde0
- Direction
- did not responde0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“On the average, however, rice yield did not respond to P.”
Claim · model-written summary
One application of 22 kg P ha‐' produced 85% of maximum cowpea yield for two years.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- A single application of 22 kg P ha‐'e0
- Outcome
- maximum yielde0
- Direction
- sufficiente0
- Value
- 85%e0
- Qualifier
- 2 yre0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A single application of 22 kg P ha‐' was sufficient to produce 85% of the maximum yield of cowpea for 2 yr.”
Claim · model-written summary
Broadcast phosphate rock is a good P source for low-input acid-soil systems using acid-tolerant cowpea cultivars.
- Taxon
- cowpeaVigna unguiculatae0
- Outcome
- broadcast phosphate rock is a good source of Pe0
- Qualifier
- low‐input systems on acid soils where acid‐tolerant cultivars are usede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The results with cowpea indicate that broadcast phosphate rock is a good source of P for low‐input systems on acid soils where acid‐tolerant cultivars are used.”
The same questions in other papers
phosphorus · yield · Vigna unguiculata (cowpea)Results differ
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See all 729 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.