Abstract
Phosphorus is one of the critical elements that limit plant production, particularly in humid and semi-humid soils. For realization of African Green Revolution, use of rock phosphate (RP) by resource-poor farmers may be an alternative to more expensive water soluble phosphate (P). Utilization of RP was investigated in tomato (Lycopersicon esculentum Mill) var; Moneymaker in minirhizotrons at Hohenheim to assess root-induced chemical changes in the rhizosphere with two soil types: - Arenosol and C-horizon of Luvisol. Additionally, field experiments were conducted atKibwezi and Maseno (Luvisol and Ferralsol, respectively) in Kenya. All trials received RP and soluble P as source of P and nitrate and ammonium (stabilized with DMPP as nitrification inhibitor) as nitrogen sources. Ammonium treatment significantly reduced rhizosphere pH in minirhizotron treatment with Arenosol with corresponding increase in shoot P content (but with significant negative shoot biomass accumulation), while rhizoplane pH differed significantly from rhizosphere pH treatment with C-horizon of Luvisol and there was no RP benefit to plant. The buffer capacity of the Luvisol was quite high and the pH 2mm away from rhizoplane was similar to that of bulk soil. However, minimal NO3 - additions to ammonium treatment significantly improved biomass production in both soils. In both rhizobox experiments, NO3 - led to rhizosphere alkalinization. Both shoot and fruit biomass was enhanced by RP application at Maseno, while RP had a negative effect on tomato plant production at Kibwezi. Therefore, role of RP on improved tomato yield at Maseno may partly be attributed to secondary factors other than P, viz; alleviation of aluminium rhizotoxicity since the Al content was significantly reduced by RP treatment, while RP may have led to partial alkalinization at specific root/rhizoplane, leading to Zinc deficiency at Kibwezi site. The application of rock phosphate in addition to acidifying nitrogenous fertilizer with consideration to soil types has potential of improving crop production and phosphate capital of resource-poor farmers.Key words: Nitrogen forms, r-phosphate, soil-types, tomato
Abstract from the paper’s OpenAlex record; open copy licensed cc-by-nc-nd. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 12
Claim · model-written summary
Ammonium lowered rhizosphere pH in Arenosol.
- Taxon
- tomato
Solanum lycopersicumt0 - Treatment
- Ammonium treatmente0
- Outcome
- rhizosphere pHe0
- Direction
- reducede0
- Setting
- Arenosole0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ammonium treatment significantly reduced rhizosphere pH in minirhizotron treatment with Arenosol with corresponding increase in shoot P content (but with significant negative shoot biomass accumulation)”
t0“tomato”
Claim · model-written summary
Ammonium increased shoot P content in Arenosol.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- Ammonium treatmente0
- Outcome
- shoot P contente0
- Direction
- increasee0
- Setting
- Arenosole0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ammonium treatment significantly reduced rhizosphere pH in minirhizotron treatment with Arenosol with corresponding increase in shoot P content (but with significant negative shoot biomass accumulation)”
t0“tomato”
Claim · model-written summary
Ammonium reduced shoot biomass accumulation in Arenosol.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- Ammonium treatmente0
- Outcome
- shoot biomass accumulatione0
- Direction
- negativee0
- Setting
- Arenosole0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ammonium treatment significantly reduced rhizosphere pH in minirhizotron treatment with Arenosol with corresponding increase in shoot P content (but with significant negative shoot biomass accumulation)”
t0“tomato”
Claim · model-written summary
RP gave no benefit to plants in C-horizon Luvisol.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- RPe0
- Outcome
- benefit to plante0
- Direction
- no RP benefite0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“there was no RP benefit to plant”
t0“tomato”
Claim · model-written summary
Minimal nitrate additions improved biomass production in both soils.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- minimal NO3 - additions to ammonium treatmente0
- Outcome
- biomass productione0
- Direction
- improvede0
- Setting
- both soilse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“minimal NO3 - additions to ammonium treatment significantly improved biomass production in both soils”
t0“tomato”
Claim · model-written summary
Nitrate alkalinized the rhizosphere in both rhizobox experiments.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- NO3 -e0
- Outcome
- rhizosphere alkalinizatione0
- Direction
- alkalinizatione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In both rhizobox experiments, NO3 - led to rhizosphere alkalinization”
t0“tomato”
Claim · model-written summary
RP enhanced shoot biomass at Maseno.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- RP applicatione0
- Outcome
- shoot and fruit biomasse0
- Direction
- enhancede0
- Setting
- Masenoe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both shoot and fruit biomass was enhanced by RP application at Maseno”
t0“tomato”
Claim · model-written summary
RP enhanced fruit biomass at Maseno.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- RP applicatione0
- Outcome
- fruit biomasse0
- Direction
- enhancede0
- Setting
- Masenoe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both shoot and fruit biomass was enhanced by RP application at Maseno”
t0“tomato”
Claim · model-written summary
RP negatively affected tomato production at Kibwezi.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- RPe0
- Outcome
- tomato plant productione0
- Direction
- negativee0
- Setting
- Kibwezie0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“RP had a negative effect on tomato plant production at Kibwezi”
Claim · model-written summary
RP reduced Al content.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- RP treatmente0
- Outcome
- Al contente0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the Al content was significantly reduced by RP treatment”
t0“tomato”
Claim · model-written summary
Authors suggest RP may alleviate aluminium rhizotoxicity at Maseno.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- RPe0
- Outcome
- improved tomato yielde0
- Qualifier
- alleviation of aluminium rhizotoxicitye0
- Setting
- Masenoe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“role of RP on improved tomato yield at Maseno may partly be attributed to secondary factors other than P, viz; alleviation of aluminium rhizotoxicity”
Claim · model-written summary
Authors suggest RP may induce Zinc deficiency at Kibwezi.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- RPe0
- Outcome
- Zinc deficiencye0
- Qualifier
- partial alkalinization at specific root/rhizoplanee0
- Setting
- Kibwezie0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“RP may have led to partial alkalinization at specific root/rhizoplane, leading to Zinc deficiency at Kibwezi site”
t0“tomato”
The same questions in other papers
nitrogen · nutrient: content · Solanum lycopersicum (tomato)Results differ
58 papers in the same direction as this paper · 17 in the opposite direction · 1 reporting no difference from an alternative
- negative
- no effect
- negative
73 papers more in this group
See all 77 papers →phosphorus · yield · Solanum lycopersicum (tomato)Results differ
20 papers in the same direction as this paper · 80 in the opposite direction
- positive
- positive
- positive
97 papers more in this group
See all 101 papers →nitrogen · soil: chemistry · Solanum lycopersicum (tomato)Positive and negative results
3 papers in the same direction as this paper · 2 in the opposite direction
- negative
- no effect
- positive
2 papers more in this group
See all 6 papers →phosphorus · molecular: metabolites · Solanum lycopersicum (tomato)Positive and negative results
14 papers in the same direction as this paper · 7 in the opposite direction
- no effect
- no effect
- no effect
18 papers more in this group
See all 22 papers →phosphorus · growth · Solanum lycopersicum (tomato)Positive and negative results
63 papers in the same direction as this paper · 12 in the opposite direction
- no effect
- negative
- negative
72 papers more in this group
See all 76 papers →nitrogen · growth · Solanum lycopersicum (tomato)Positive and negative results
44 papers in the same direction as this paper · 108 in the opposite direction
- negative
- positive
- positive
149 papers more in this group
See all 153 papers →nitrogen · yield · Solanum lycopersicum (tomato)Positive and negative results
171 papers in the same direction as this paper · 31 in the opposite direction · 7 reporting no difference from an alternative
- negative
- negative
- negative
206 papers more in this group
See all 210 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.