Abstract
The impoverished Namibian soils can very well be enriched with nutrients by applying cattle manure, especially when resource-poor farmers are unable to purchase expensive chemical fertilizers. In this study, effects of cattle manure on different cropping patterns, i.e., mono- and mixed-cropping of pearl millet (Pennisetum glaucum L.) and cowpea (Vigna unguiculata L.) were compared across three cropping seasons at manure application rates of 0, 31 and 62 Mg ha−1. The experimental plots were laid out in a randomized complete-block design with four replications. The parameters measured were growth and yield of the crops, soil organic carbon (SOC), total soil N, available soil P, and exchangeable soil K. The SOC was determined by the Black-Walkley protocol, total N by the modified Kjeldahl method, available P by the Olsen method, and exchangeable K by ammonium acetate extraction. Application of 31 Mg ha−1 cattle manure increased SOC, total soil N, available P, and exchangeable K 1.3, 1.2, 1.2, and 1.4 times, respectively, over the control; the respective increase by the addition of 62 Mg ha−1 was 1.7, 1.5, 1.3, and 2.1 times. However, differences between 31 and 62 Mg ha−1 manure were not significant for SOC, total soil N, and available P, except for exchangeable K. Both grain yield and biomass yield of pearl millet increased with the application of 31 Mg ha−1 manure, but declined with the application of 62 Mg ha−1 manure, whereas grain yield and biomass yield of cowpea declined with the addition of 62 Mg ha−1 manure. Both cowpea and pearl millet yielded more when intercropped than when grown as monocultures.
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Claims 15
Claim · model-written summary
31 Mg ha−1 manure increased soil organic carbon 1.3 times over control.
- Taxon
- pearl millet and cowpea
Vigna unguiculata
Cenchrus americanust0 - Treatment
- 31 Mg ha−1 cattle manuree0
- Outcome
- SOCe0
- Direction
- increasede0
- Value
- 1.3e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Application of 31 Mg ha−1 cattle manure increased SOC, total soil N, available P, and exchangeable K 1.3, 1.2, 1.2, and 1.4 times, respectively, over the control”
t0“pearl millet and cowpea”
Claim · model-written summary
31 Mg ha−1 manure increased total soil N 1.2 times.
- Taxon
- pearl millet and cowpeaVigna unguiculataCenchrus americanust0
- Treatment
- 31 Mg ha−1 cattle manuree0
- Outcome
- total soil Ne0
- Direction
- increasede0
- Value
- 1.2e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Application of 31 Mg ha−1 cattle manure increased SOC, total soil N, available P, and exchangeable K 1.3, 1.2, 1.2, and 1.4 times, respectively, over the control”
t0“pearl millet and cowpea”
Claim · model-written summary
31 Mg ha−1 manure increased available soil P 1.2 times.
- Taxon
- pearl millet and cowpeaVigna unguiculataCenchrus americanust0
- Treatment
- 31 Mg ha−1 cattle manuree0
- Outcome
- available Pe0
- Direction
- increasede0
- Value
- 1.2e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Application of 31 Mg ha−1 cattle manure increased SOC, total soil N, available P, and exchangeable K 1.3, 1.2, 1.2, and 1.4 times, respectively, over the control”
t0“pearl millet and cowpea”
Claim · model-written summary
31 Mg ha−1 manure increased exchangeable soil K 1.4 times.
- Taxon
- pearl millet and cowpeaVigna unguiculataCenchrus americanust0
- Treatment
- 31 Mg ha−1 cattle manuree0
- Outcome
- exchangeable Ke0
- Direction
- increasede0
- Value
- 1.4e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Application of 31 Mg ha−1 cattle manure increased SOC, total soil N, available P, and exchangeable K 1.3, 1.2, 1.2, and 1.4 times, respectively, over the control”
t0“pearl millet and cowpea”
Claim · model-written summary
62 Mg ha−1 manure increased SOC 1.7 times.
- Taxon
- pearl millet and cowpeaVigna unguiculataCenchrus americanust0
- Treatment
- 62 Mg ha−1e0
- Outcome
- soil propertiest0
- Direction
- increasee0
- Value
- 1.7e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the respective increase by the addition of 62 Mg ha−1 was 1.7, 1.5, 1.3, and 2.1 times.”
t0“soil properties and growth and yield of pearl millet and cowpea”
Claim · model-written summary
62 Mg ha−1 manure increased total soil N 1.5 times.
- Taxon
- pearl millet and cowpeaVigna unguiculataCenchrus americanust0
- Treatment
- 62 Mg ha−1e0
- Outcome
- soil propertiest0
- Direction
- increasee0
- Value
- 1.5e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the respective increase by the addition of 62 Mg ha−1 was 1.7, 1.5, 1.3, and 2.1 times.”
t0“soil properties and growth and yield of pearl millet and cowpea”
Claim · model-written summary
62 Mg ha−1 manure increased available soil P 1.3 times.
- Taxon
- pearl millet and cowpeaVigna unguiculataCenchrus americanust0
- Treatment
- 62 Mg ha−1e0
- Outcome
- soil propertiest0
- Direction
- increasee0
- Value
- 1.3e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the respective increase by the addition of 62 Mg ha−1 was 1.7, 1.5, 1.3, and 2.1 times.”
t0“soil properties and growth and yield of pearl millet and cowpea”
Claim · model-written summary
62 Mg ha−1 manure increased exchangeable soil K 2.1 times.
- Taxon
- pearl millet and cowpeaVigna unguiculataCenchrus americanust0
- Treatment
- 62 Mg ha−1e0
- Outcome
- soil propertiest0
- Direction
- increasee0
- Value
- 2.1 timese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the respective increase by the addition of 62 Mg ha−1 was 1.7, 1.5, 1.3, and 2.1 times.”
t0“soil properties and growth and yield of pearl millet and cowpea”
Claim · model-written summary
SOC, total soil N and available P did not differ significantly between manure rates.
- Taxon
- pearl millet and cowpeaVigna unguiculataCenchrus americanust0
- Outcome
- SOC, total soil N, and available Pe0
- Direction
- not significante0
- Comparator
- 31 and 62 Mg ha−1 manuree0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“differences between 31 and 62 Mg ha−1 manure were not significant for SOC, total soil N, and available P”
t0“pearl millet and cowpea”
Claim · model-written summary
Exchangeable K differed significantly between manure rates.
- Taxon
- pearl millet and cowpeaVigna unguiculataCenchrus americanust0
- Outcome
- exchangeable Ke0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“except for exchangeable K.”
t0“pearl millet and cowpea”
Claim · model-written summary
31 Mg ha−1 manure increased pearl millet grain and biomass yield.
- Taxon
- pearl milletCenchrus americanuse0
- Treatment
- 31 Mg ha−1 manuree0
- Outcome
- grain yield and biomass yield of pearl millete0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both grain yield and biomass yield of pearl millet increased with the application of 31 Mg ha−1 manure”
Claim · model-written summary
62 Mg ha−1 manure decreased pearl millet grain and biomass yield.
- Taxon
- pearl milletCenchrus americanust0
- Treatment
- 62 Mg ha−1 manuree0
- Outcome
- growth and yield of pearl millett0
- Direction
- declinede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“declined with the application of 62 Mg ha−1 manure”
t0“growth and yield of pearl millet”
Claim · model-written summary
62 Mg ha−1 manure decreased cowpea grain and biomass yield.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- 62 Mg ha−1 manuree0
- Outcome
- grain yield and biomass yield of cowpeae0
- Direction
- declinede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“grain yield and biomass yield of cowpea declined with the addition of 62 Mg ha−1 manure”
Claim · model-written summary
Intercropped cowpea yielded more than monoculture cowpea.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- intercroppede0
- Outcome
- yieldede0
- Direction
- moree0
- Comparator
- monoculturese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both cowpea and pearl millet yielded more when intercropped than when grown as monocultures.”
Claim · model-written summary
Intercropped pearl millet yielded more than monoculture pearl millet.
- Taxon
- pearl milletCenchrus americanuse0
- Treatment
- intercroppede0
- Outcome
- yieldede0
- Direction
- moree0
- Comparator
- monoculturese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both cowpea and pearl millet yielded more when intercropped than when grown as monocultures.”
The same questions in other papers
intercropping · yield · Cenchrus americanus (pearl millet)Results differ
46 papers in the same direction as this paper · 11 in the opposite direction · 2 reporting no difference from an alternative
- negative
- negative
- negative
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See all 60 papers →intercropping · yield · Vigna unguiculata (cowpea)Results differ
62 papers in the same direction as this paper · 33 in the opposite direction · 7 reporting no difference from an alternative
- negative
- negative
- no effect
99 papers more in this group
See all 103 papers →fertilization · soil: chemistry · Vigna unguiculata (cowpea)Positive and negative results
13 papers in the same direction as this paper · 3 in the opposite direction · 1 reporting no difference from an alternative
- no effect
- negative
- negative
14 papers more in this group
See all 18 papers →fertilization · soil: chemistry · Cenchrus americanus (pearl millet)Positive and negative results
21 papers in the same direction as this paper · 1 in the opposite direction
- no effect
- positive
- positive
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See all 23 papers →fertilization · yield · Cenchrus americanus (pearl millet)Positive and negative results
248 papers in the same direction as this paper · 9 in the opposite direction · 1 reporting no difference from an alternative
- positive
- no effect
- negative
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See all 259 papers →fertilization · yield · Vigna unguiculata (cowpea)Positive and negative results
16 papers in the same direction as this paper · 275 in the opposite direction
- positive
- positive
- positive
288 papers more in this group
See all 292 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.