Abstract
Abstract Hawkeye (resistant to iron chlorosis) and PI54619–5–1 (susceptible to iron chlorosis) soybeans (Glycine max L.) were grown in calcareous Hacienda loam soil (fine‐loam, mixed, thermic Aquic Natrargid) for 26 days in a glasshouse. Objectives of the study included an evaluation of iron chlorosis as phosphorus and nitrogen were varied. The 2×2×2 factorial study with Fe, P and N (with and without each) provided the possibility for a look at three deficiencies simultaneously with some assessment of the use of the Colby (1968) technique for multiple stresses acting simultaneously. Iron addition (2 μg/g soil as FeEDDHA) overcame iron deficiency and increased yields. Nitrogen (200 μg N/g soil as NH4NO3) increased yields only when both iron and phosphorus were also applied with one cultivar (Hawkeye); nitrogen increased yield in combination with iron or with iron plus phosphorus with the second cultivar (PI54619–5–1). Phosphorus (100 μg P/g soil as CaH2PO4), on the average, had no effect on yields of either cultivar but, with both iron and nitrogen also added, it increased yields for both cultivars. With the PI54619–5–1 cultivar phosphorus increased yield also when iron but not nitrogen was added. Without added iron, nitrogen alone depressed plant yields to the plants especially with the PI54619–5–1 cultivar and nitrogen plus phosphorus without iron was even more depressive of yields. The effect of the nitrogen, however, was expressed as iron chlorosis. The experiment produced bonafide phosphorus‐induced iron chlorosis. Phosphorus alone was much less effective than both nitrogen and phosphorus in inducing the chlorosis expressed as yellow leaf chlorosis. Relative yields expressed by the Colby (1968) procedure indicated that with plants reasonably free of interactions, additive effects were obtained. For example, the nitrogen treatment with Hawkeye at 113% of the untreated and the iron‐treatment at 144% were essentially equal to the nitrogen plus iron treatment of 161% vs the 163% calculated (1.13 × 1.44 = 1.63). The iron plus phosphorus treatment at 141% and the iron plus nitrogen at 161% were close to the treatment with all three variables added with 213% for actual and 227% calculated (1.41 × 1.61 = 2.27). These effects have implications on the law of the minimum. Many interactions were expressed in the mineral analyses as well as in the yields. Some of these were related to dilution. Interactions on composition for mineral elements were present with one or more pairs of the added elements or for all three for phosphorus, iron, manganese, zinc, potassium, calcium, and some other elements. The PI54619–5–1 withmore iron chlorosis had more interactions than did the Hawkeye soybean.
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Claims 14
Claim · model-written summary
Iron addition overcame iron deficiency and increased soybean yields.
- Taxon
- soybeans
Glycine maxt0 - Treatment
- Iron addition (2 μg/g soil as FeEDDHA)e0
- Outcome
- yieldse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Iron addition (2 μg/g soil as FeEDDHA) overcame iron deficiency and increased yields.”
t0“soybeans”
Claim · model-written summary
Nitrogen increased Hawkeye yield only when both iron and phosphorus were applied.
- Taxon
- soybeansGlycine maxt0
- Material
- Hawkeyee0
- Treatment
- Nitrogen (200 μg N/g soil as NH4NO3)e0
- Outcome
- yieldse0
- Direction
- increasede0
- Qualifier
- only when both iron and phosphorus were also appliede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen (200 μg N/g soil as NH4NO3) increased yields only when both iron and phosphorus were also applied with one cultivar (Hawkeye)”
t0“soybeans”
Claim · model-written summary
Nitrogen increased PI54619–5–1 yield with iron, alone or with phosphorus.
- Taxon
- soybeansGlycine maxt0
- Material
- PI54619–5–1e0
- Treatment
- nitrogene0
- Outcome
- yielde0
- Direction
- increasede0
- Qualifier
- in combination with iron or with iron plus phosphoruse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“nitrogen increased yield in combination with iron or with iron plus phosphorus with the second cultivar (PI54619–5–1).”
t0“soybeans”
Claim · model-written summary
Phosphorus had no average yield effect in either soybean cultivar.
- Taxon
- soybeansGlycine maxt0
- Treatment
- Phosphorus (100 μg P/g soil as CaH2PO4)e0
- Outcome
- yieldse0
- Direction
- had no effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Phosphorus (100 μg P/g soil as CaH2PO4), on the average, had no effect on yields of either cultivar”
t0“soybeans”
Claim · model-written summary
Phosphorus increased yields of both cultivars when iron and nitrogen were also supplied.
- Taxon
- soybeansGlycine maxt0
- Treatment
- Phosphorus (100 μg P/g soil as CaH2PO4)e1
- Outcome
- yieldse0
- Direction
- increasede0
- Qualifier
- with both iron and nitrogen also addede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“with both iron and nitrogen also added, it increased yields for both cultivars.”
e1“Phosphorus (100 μg P/g soil as CaH2PO4)”
t0“soybeans”
Claim · model-written summary
Phosphorus increased PI54619–5–1 yield when iron, but not nitrogen, was supplied.
- Taxon
- soybeansGlycine maxt0
- Material
- PI54619–5–1e0
- Treatment
- phosphoruse0
- Outcome
- yielde0
- Direction
- increasede0
- Qualifier
- when iron but not nitrogen was addede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With the PI54619–5–1 cultivar phosphorus increased yield also when iron but not nitrogen was added.”
t0“soybeans”
Claim · model-written summary
Without iron, nitrogen alone depressed soybean yields, particularly for PI54619–5–1.
- Taxon
- soybeansGlycine maxt0
- Material
- PI54619–5–1e0
- Treatment
- nitrogen alonee0
- Outcome
- plant yieldse0
- Direction
- depressede0
- Qualifier
- Without added irone0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Without added iron, nitrogen alone depressed plant yields to the plants especially with the PI54619–5–1 cultivar”
t0“soybeans”
Claim · model-written summary
Without iron, nitrogen plus phosphorus depressed yields even more.
- Taxon
- soybeansGlycine maxt0
- Treatment
- nitrogen plus phosphorus without irone0
- Outcome
- yieldse0
- Direction
- more depressivee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“nitrogen plus phosphorus without iron was even more depressive of yields.”
t0“soybeans”
Claim · model-written summary
Nitrogen effects appeared as iron chlorosis, and phosphorus-induced chlorosis was observed.
- Taxon
- soybeansGlycine maxt0
- Treatment
- nitrogene0
- Outcome
- iron chlorosise0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The effect of the nitrogen, however, was expressed as iron chlorosis. The experiment produced bonafide phosphorus‐induced iron chlorosis.”
t0“soybeans”
Claim · model-written summary
Phosphorus alone induced less yellow leaf chlorosis than phosphorus with nitrogen.
- Taxon
- soybeansGlycine maxt0
- Treatment
- Phosphorus alonee0
- Outcome
- yellow leaf chlorosise0
- Direction
- much less effectivee0
- Comparator
- both nitrogen and phosphoruse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Phosphorus alone was much less effective than both nitrogen and phosphorus in inducing the chlorosis expressed as yellow leaf chlorosis.”
t0“soybeans”
Claim · model-written summary
For Hawkeye, measured nitrogen plus iron relative yield was 161%, close to the 163% additive prediction.
- Taxon
- soybeansGlycine maxt0
- Material
- Hawkeyee0
- Outcome
- nitrogen plus iron treatmente0
- Value
- 161%e0
- Qualifier
- 163% calculatede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the nitrogen treatment with Hawkeye at 113% of the untreated and the iron‐treatment at 144% were essentially equal to the nitrogen plus iron treatment of 161% vs the 163% calculated”
t0“soybeans”
Claim · model-written summary
The triple treatment yielded 213% of untreated, close to the 227% additive prediction.
- Taxon
- soybeansGlycine maxt0
- Outcome
- treatment with all three variables addede0
- Value
- 213%e0
- Qualifier
- 227% calculatede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the treatment with all three variables added with 213% for actual and 227% calculated”
t0“soybeans”
Claim · model-written summary
Added nutrients interacted in soybean mineral composition across phosphorus, iron, manganese, zinc, potassium and calcium.
- Taxon
- soybeansGlycine maxt0
- Outcome
- Interactions on composition for mineral elementse0
- Qualifier
- phosphorus, iron, manganese, zinc, potassium, calcium, and some other elementse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Interactions on composition for mineral elements were present with one or more pairs of the added elements or for all three for phosphorus, iron, manganese, zinc, potassium, calcium, and some other elements.”
t0“soybeans”
Claim · model-written summary
PI54619–5–1, the more chlorotic cultivar, exhibited more nutrient interactions than Hawkeye.
- Taxon
- soybeanGlycine maxe0
- Material
- PI54619–5–1e0
- Outcome
- interactionse0
- Direction
- moree0
- Comparator
- Hawkeyee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The PI54619–5–1 withmore iron chlorosis had more interactions than did the Hawkeye soybean.”
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