Abstract
Low available soil phosphorus (P) is associated with its immobility, which renders it unavailable for plant uptake. In addition, farmers normally apply inorganic fertilisers to legumes to activate soil-bound phosphorus using root exudates. Sufficient soil mineral nutrition is key to sustainable crop production, and hence food and nutritional security. The aim of this study was to quantify the acid and alkaline phosphatase activity as an indicator of P supply and availability under varying levels of nitrogen, phosphorus and potassium (NPK) fertilization and different cropping systems. An intercropping (cowpea and amaranth) and fertiliser (control, 25%, 50%, and 100% of the recommended NPK levels) field trial was laid out in a 2 × 4 factorial treatment structure in a completely randomized design (CRD) with four replications. There was higher acid and alkaline phosphatase activity in the rhizosphere of cowpea and amaranth grown as sole crops compared to those from intercropping. The cowpea and amaranth plants grown without fertiliser or 25% NPK had the highest rhizospheric phosphatase activity, while 100% NPK application exhibited the least. The markedly higher phosphatase activity from the low fertiliser application treatments indicates the possible stimulation of microbial activity to supplement P demands for the crops. The study revealed that the application of lower rates inorganic fertilisers in a legume intercrop stimulates the activity of the phosphatase enzymes, which can subsequently liberate soil-bound phosphorus. Plant tissue phosphorus concentration of cowpea and amaranth plants increased proportionately to the increase in fertiliser application up to 50% of the recommended NPK level. The land equivalent ratio (LER) was greater than 1, indicating that it is more beneficial to intercrop cowpea and amaranth as opposed to growing them as sole crops. Overall, the application of NPK fertilizer to amounts of up to 50%, based on the results of this study, appear to be better than 100% in terms of biomass accumulation and phosphate activity.
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Claims 7
Claim · model-written summary
Sole cowpea had higher rhizosphere phosphatase activity than intercropped cowpea.
- Taxon
- cowpea
Vigna unguiculatae0 - Treatment
- sole cropse0
- Outcome
- acid and alkaline phosphatase activitye0
- Direction
- highere0
- Comparator
- intercroppinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“higher acid and alkaline phosphatase activity in the rhizosphere of cowpea and amaranth grown as sole crops compared to those from intercropping”
Claim · model-written summary
Sole amaranth had higher rhizosphere phosphatase activity than intercropped amaranth.
- Taxon
- amaranth
.JPG?width=60)
Amaranthus caudatuse0 - Treatment
- sole cropse0
- Outcome
- acid and alkaline phosphatase activitye0
- Direction
- highere0
- Comparator
- intercroppinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.JPG?width=500)
Verbatim
e0“higher acid and alkaline phosphatase activity in the rhizosphere of cowpea and amaranth grown as sole crops compared to those from intercropping”
Claim · model-written summary
No fertilizer or 25% NPK produced highest rhizosphere phosphatase activity.
- Taxon
- cowpea and amaranth plantsAmaranthus caudatusVigna unguiculatae0
- Treatment
- without fertiliser or 25% NPKe0
- Outcome
- rhizospheric phosphatase activitye0
- Direction
- higheste0
- Comparator
- 100% NPKe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cowpea and amaranth plants grown without fertiliser or 25% NPK had the highest rhizospheric phosphatase activity, while 100% NPK application exhibited the least”
Claim · model-written summary
Cowpea tissue phosphorus increased with fertilizer to 50% NPK.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- fertiliser application up to 50% of the recommended NPK levele0
- Outcome
- Plant tissue phosphorus concentratione0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plant tissue phosphorus concentration of cowpea and amaranth plants increased proportionately to the increase in fertiliser application up to 50% of the recommended NPK level”
Claim · model-written summary
Amaranth tissue phosphorus increased with fertilizer to 50% NPK.
- Taxon
- amaranthAmaranthus caudatuse0
- Treatment
- fertiliser application up to 50% of the recommended NPK levele0
- Outcome
- Plant tissue phosphorus concentratione0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plant tissue phosphorus concentration of cowpea and amaranth plants increased proportionately to the increase in fertiliser application up to 50% of the recommended NPK level”
Claim · model-written summary
Cowpea-amaranth intercropping had land equivalent ratio above one.
- Taxon
- cowpea and amaranthAmaranthus caudatusVigna unguiculatae0
- Outcome
- land equivalent ratio (LER)e0
- Direction
- greater thane0
- Value
- 1e0
- Comparator
- sole cropse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The land equivalent ratio (LER) was greater than 1, indicating that it is more beneficial to intercrop cowpea and amaranth as opposed to growing them as sole crops”
Claim · model-written summary
NPK up to 50% appears better than 100% for biomass accumulation and phosphatase activity.
- Treatment
- NPK fertilizer to amounts of up to 50%e0
- Outcome
- biomass accumulation and phosphate activitye0
- Direction
- bettere0
- Comparator
- 100%e0
Not reportedTaxon
Verbatim
e0“application of NPK fertilizer to amounts of up to 50%, based on the results of this study, appear to be better than 100% in terms of biomass accumulation and phosphate activity”
The same questions in other papers
fertilization · soil: biology · Vigna unguiculata (cowpea)Positive and negative results
6 papers in the same direction as this paper · 1 reporting no difference from an alternative
- positive
- no effect
- positive
4 papers more in this group
See all 8 papers →intercropping · soil: biology · Vigna unguiculata (cowpea)Results agree
2 papers in the same direction as this paper
- positive
- positive
fertilization · soil: biology · Amaranthus caudatus (amaranth)Results agree
2 papers in the same direction as this paper
- positive
- positive
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.