Intervention effectmodel-written summary

Cowpea biomass increased as NPK fertilizer rose to 100%.

A claim from Assessment of the effects of NPK fertilizer on edible yield and agro-biological parameters in a cowpea–amaranth intercrop · 2023

Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Cowpea biomass increased as NPK fertilizer rose to 100%.

Treatment
increased fertilizer application up to the level of 100% nitrogen, phosphorus, and potassium (NPK) fertilizere0
Outcome
biomass of amaranth and cowpeae0
Direction
increasede0

Not reportedMaterialGeneCompoundOrgan / stageInteractorInteractor roleSecond interactorSecond interactor roleComparatorSettingValueQualifier

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Vigna unguiculata
Vigna unguiculata · TaxonHeraldDesa at English Wikipedia · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

e0

“The biomass of amaranth and cowpea increased with increased fertilizer application up to the level of 100% nitrogen, phosphorus, and potassium (NPK) fertilizer.”

✓ located verbatim in the source · abstract, characters 622–782

Title

Assessment of the effects of NPK fertilizer on edible yield and agro-biological parameters in a cowpea–amaranth intercrop

Buhlebelive Mndzebele; Bhekumthetho Ncube; Melake Fessehazion; et al. Frontiers in Sustainable Food Systems 2023. doi:10.3389/fsufs.2023.1210984

Other claims from this paper (6)

Record rev-30a63fcfda74e64109a47161f1d31ccca4d723512e75ab10f78903c94d9713c1 · schema claims-v0.9 · position 2 in the model’s answer

phosphorus · growth · Vigna unguiculata (cowpea)Results differ

56 papers: 52 positive, 4 negative or no effect

51 papers in the same direction as this claim · 4 in the opposite direction

  1. negative
    Leaf area of cowpea was reduced under low P

    Acid phosphatase activity in bean and cowpea plants grown under phosphorus stress · 1994 · compared with 1.0

    Opposite direction

  2. negative
    Phosphorus combined with different doses of manipueira had a negative effect on the initial development (V4 stage) of cowpea in a greenhouse, relative to mineral fertilization.

    Growth and formation of bean phytomass (Vigna unguiculata L.) fertilized with mineral fertilizer and manipueira · 2018 · compared with mineral fertilization

    Opposite direction

  3. no effect
    Plant height and leaf number did not vary with varieties or phosphorus.

    Response of fodder cowpea (Vigna unguiculata) varieties to application of phosphorus · 2001

    Opposite direction

  4. no effect
    Phosphorus did not significantly affect cowpea growth parameters.

    Performance of cowpea varieties under different phosphorus levels and spacing in Tanzania · 2025

    Opposite direction

  5. positive
    Phosphorus increased cowpea shoot dry weight and shoot and grain nitrogen content across locations.

    Growth and Yield Responses of Cowpea to Inoculation and Phosphorus Fertilization in Different Environments · 2017

    Same direction

  6. positive
    Phosphorus application significantly improved cowpea growth.

    Organic acids in the rhizosphere and root characteristics of soybean (Glycine max) and cowpea (Vigna unguiculata) in relation to phosphorus uptake in poor savanna soils · 2008

    Same direction

  7. positive
    Phosphorus application significantly enhanced shoot and root dry weight and total biomass of cowpea genotypes.

    Phosphorus Response Efficiency in Cowpea Genotypes · 2011

    Same direction

  8. positive
    Single super phosphate gave a higher total biomass than phosphate rocks in maize and cowpea.

    Effects of phosphate rock application on dry matter yield and phosphorus recovery of maize and cowpea grown in sequence · 2010 · compared with phosphate rocks (PR)

    Same direction

47 papers more in this group

See all 56 papers →

potassium · growth · Vigna unguiculata (cowpea)Positive and negative results

19 papers: 18 positive, 1 negative or no effect

17 papers in the same direction as this claim · 1 in the opposite direction

  1. negative
    Higher potassium rates with salinity depressed main stem growth relative to salinity alone.

    Growth and gas exchange in the cowpea under saline irrigation and rates of potassium = Crescimento e trocas gasosas de plantas de feijão-caupi sob irrigação salina e doses de potássio · 2015 · compared with isolated effect of salinity

    Opposite direction

  2. positive
    Potassium promoted growth of both mungbean and cowpea under suboptimal soil moisture.

    Influence of Soil Moisture and Fertilizer Potassium on the Vegetative Growth of Mungbean (Vigna radiata L. Wilczek) and Cowpea (Vigna unguiculata L. Walp) · 2001

    Same direction

  3. positive
    Cowpea dry matter increased significantly at 100 ppm humic acid and 300 kg/ha potassium.

    The effect of different levels of humic acid and potassium fertilizer on physiological indices of growth · 2014

    Same direction

  4. positive
    Inoculant followed by P and K fertilizer was effective for cowpea growth in field conditions.

    Combined Application of Inoculant, Phosphorus and Potassium Enhances Cowpea Yield in Savanna Soils · 2020

    Same direction

  5. positive
    T6 produced significantly higher plant height (204.6 cm) in fodder cowpea or postharvest soil.

    Effect of Organic and Inorganic Nutrient Sources on Growth, Yield, Nutrient Uptake and Economics of Fodder Cowpea [Vigna unguiculata (L.) Walp.] · 2020

    Same direction

  6. positive
    Low potassium alone significantly reduced cowpea shoot and leaf biomass.

    Influence of ultraviolet-B enhanced solar radiation on growth and photosynthesis of potassium deficient cowpea seedlings · 1999

    Same directionAbout lacking this nutrient, so it counts the other way round

  7. positive
    Potassium up to 129 kg. h-1 significantly increased plant length to 53.33 cm versus control.

    Response of Three Varieties of Cowpea( Vigna sinensis L.) to Different levels of potassium fertilizer under southern region conditions of Iraq · 2019 · compared with control

    Same direction

  8. positive
    The combined amendments increased plant fresh and dry weight.

    Effect of Feldspar, Compost and Biochar on Cultivating Cowpea (Vigna unguiculata ssp. unguiculata) Plant and Soil Sandy Clay Loam Properties · 2022

    Same direction

10 papers more in this group

See all 19 papers →

nitrogen · growth · Vigna unguiculata (cowpea)Positive and negative results

45 papers: 39 positive, 6 negative or no effect

38 papers in the same direction as this claim · 6 in the opposite direction

  1. negative
    Cerium affected root growth more adversely than shoot growth.

    Effect of cerium on growth, dry matter production, biochemical constituents and enzymatic activities of cowpea plants [Vigna unguiculata (L.) Walp.] · 2012 · compared with shoot growth

    Opposite direction

  2. no effect
    Nitrogen fertilizer did not significantly affect plant branching.

    Effect of nitrogen fertilizer on yield contributing character, biomass yield and nutritive value of cowpea forage · 1970

    Opposite direction

  3. no effect
    Nitrogen application did not improve growth of plants affected by light and temperature.

    Effects of light and temperature on nodulation of cowpea and hyacinth bean · 1975

    Opposite direction

  4. negative
    Urea with inoculation produced the lowest number and dry weight of nodules per plant.

    Effect of Rhizobium inoculation and various sources of nitrogen on growth and yield of cowpea [Vigna unguiculata (L.) Walp.] · 2005 · compared with Vermicompost x inoculation

    Opposite direction

  5. negative
    At 25 kg N/fad., cowpea phloem and xylem thickness and pith diameter were lower than at 35 kg N/fad.

    EFFECT OF LITHOVIT ON GROWTH, SEED YIELD COMPONENTS AND ANATOMY OF STEM AND LEAF OF COWPEA PLANTS UNDER DIFFERENT MINERAL NITROGEN LEVELS · 2018 · compared with 35 kg N/fad.

    Opposite direction

  6. negative
    Nitrogen fertilization gave cowpea the least weight across both years.

    SYMBIOTIC EFFECTIVENESS OF BRAZILIAN RHIZOBIAL STRAINS IN IMPROVING N-FIXATION AND PRODUCTIVITY OF COWPEA IN MINNA, SOUTHERN GUINEA SAVANNA OF NIGERIA · 2019

    Opposite direction

  7. positive
    Leaf-applied urea slightly increased Vigna top dry weight.

    Nodulation and nitrogen fixation by Vigna sinensis and Vicia atropurpurea : The influence of concentration, form, and site of application of combined nitrogen · 1970

    Same direction

  8. positive
    Inorganic nitrogen stimulated cowpea vegetative growth compared with effectively nodulated plants.

    Effects of short-term waterlogging on growth and yield of cowpea (Vigna unguiculata) · 1978 · compared with effectively nodulated plants

    Same direction

36 papers more in this group

See all 45 papers →

3 of 4 groups shown: named compounds and organisms first, then groups whose results differ (checked claim by claim), then those with positive and negative results, then the smaller groups.

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.