Abstract
Abstract Mechanistic models need to be validated before being widely used. The Barber‐Cushman mechanistic nutrient uptake model has successfully predicted phosphorus (P) uptake in high‐P soils, but it has not been tested in soils with low available P. Some assumptions of this model (no influence of mycor‐rhizae and root hairs on nutrient uptake) may have different implications according to the soil P level. The objective of this study was to test the ability of the Barber‐Cushman model to predict P uptake for corn in an Oxisol with low P values as influenced by mycorrhizae inoculation. The experiment was carried out in a greenhouse, in a factorial with two levels of P (25 and 100 mg/kg), of limestone (pH 4.7 and 5.5), and of mycorrhizae inoculation (with and without). Observed P uptake was determined in the roots and in the shoots of 46‐day‐old corn plants. The predicted P uptake by the model was calculated using a computer program. There was a good agreement between observed and predicted P uptake (r2 = 0.97). The model, however, underpredicted the amount of P taken up by corn plants, probably due to the contribution of root hairs. Inoculation with mycorrhizae did not affect corn yield and had a small influence on both observed and predicted P uptake. The model predicted, respectively, 31% and 41% of the P taken up by plants for treatments with and without mycorrhizae inoculation. Sensitivity analysis demonstrated that P in the soil solution and the rate of root growth were the parameters that most influenced predicted P uptake, and that plant uptake kinetics had a small contribution.
Abstract from the paper’s OpenAlex record; open copy licensed other-oa. 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 7
Claim · model-written summary
Observed and predicted corn phosphorus uptake agreed closely.
- Taxon
- corn
Zea mays subsp. mayse1 - Outcome
- agreement between observed and predicted P uptakee0
- Value
- r2 = 0.97e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There was a good agreement between observed and predicted P uptake (r2 = 0.97).”
e1“P uptake for corn in an Oxisol”
Claim · model-written summary
The model underpredicted corn phosphorus uptake.
- Taxon
- cornZea mays subsp. mayse0
- Outcome
- amount of P taken up by corn plantse0
- Direction
- underpredictede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The model, however, underpredicted the amount of P taken up by corn plants”
Claim · model-written summary
Mycorrhizal inoculation did not significantly affect corn yield.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- Inoculation with mycorrhizaee0
- Interactor
- mycorrhizaee0symbiont
- Outcome
- corn yielde0
- Direction
- did not affecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Inoculation with mycorrhizae did not affect corn yield”
Claim · model-written summary
Mycorrhizal inoculation had a small influence on observed and predicted phosphorus uptake.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- Inoculation with mycorrhizaee0
- Interactor
- mycorrhizaee0symbiont
- Outcome
- observed and predicted P uptakee0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Inoculation with mycorrhizae did not affect corn yield and had a small influence on both observed and predicted P uptake.”
Claim · model-written summary
The model predicted 31% of measured P uptake with mycorrhizal inoculation.
- Taxon
- cornZea mays subsp. mayse1
- Treatment
- mycorrhizae inoculatione0
- Interactor
- mycorrhizaee0symbiont
- Outcome
- P taken up by plantse0
- Value
- 31%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The model predicted, respectively, 31% and 41% of the P taken up by plants for treatments with and without mycorrhizae inoculation.”
e1“P uptake for corn in an Oxisol”
Claim · model-written summary
The model predicted 41% of measured P uptake without mycorrhizal inoculation.
- Taxon
- cornZea mays subsp. mayse1
- Treatment
- without mycorrhizae inoculatione0
- Outcome
- P taken up by plantse0
- Value
- 41%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The model predicted, respectively, 31% and 41% of the P taken up by plants for treatments with and without mycorrhizae inoculation.”
e1“P uptake for corn in an Oxisol”
Claim · model-written summary
Soil solution P and root growth rate most influenced predicted uptake; plant uptake kinetics contributed little.
- Taxon
- cornZea mays subsp. mayse1
- Outcome
- predicted P uptakee0
Not reportedComparatorValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Sensitivity analysis demonstrated that P in the soil solution and the rate of root growth were the parameters that most influenced predicted P uptake, and that plant uptake kinetics had a small contribution.”
e1“P uptake for corn in an Oxisol”
The same questions in other papers
mycorrhiza · yield · Zea mays (maize)Results differ
8 papers in the same direction as this paper · 104 in the opposite direction
- positive
- positive
- positive
109 papers more in this group
See all 113 papers →inoculation · yield · Zea mays (maize)Positive and negative results
58 papers in the same direction as this paper · 479 in the opposite direction
- positive
- positive
- positive
534 papers more in this group
See all 538 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.