Abstract
The response of soybean [ Glycine max (L.) Merr.] to foliar fertilization during early growth stages has received little attention. Recent Iowa research showed a 15% probability of positive yield response to a 3–15–8 (N–P–K) fertilizer applied at the V5 growth stage. This study evaluated the effects of fertilizers varying in N–P–K ratio on soybean grain yield and tissue nutrient composition. Twenty‐seven field trials were conducted in soils that tested at or above optimum soil P and K levels for soybean. Six treatments included a control and nonfactorial combinations of rates and application frequency of 28 to 56 L ha −1 of 3–8–15, 10–4–8, and 8–0–7 fertilizers sprayed at the V5 stage. Differences between treatments were inconsistent across sites. Some or all treatments increased or decreased yields significantly at six sites. The mean yield increase or decrease for responsive sites was 400 kg ha −1 . The 3–8–15 fertilizer caused no leaf damage and other fertilizers caused little or no damage, although the damage was not clearly related with yield decreases. Analyses by site showed that fertilization seldom increased tissue N–P–K composition, nutrient uptake, photosynthesis, or plant weight measured at the R2 growth stage. Multivariate analyses across sites showed that 27% of the variation in yield response was explained by a combination of N, P, and K availability, vegetative growth, and rainfall. Positive yield responses tended to occur when soil or weather conditions reduced plant growth and nutrient availability. Foliar fertilization across all conditions will not offset the application costs.
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Claims 11
Claim · model-written summary
Foliar fertilizer treatments significantly increased yields at some of six responsive sites.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Some or all treatments increased or decreased yields significantly at six sites.”
t0“Soybean”
Claim · model-written summary
Foliar fertilizer treatments significantly decreased yields at some of six responsive sites.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Some or all treatments increased or decreased yields significantly at six sites.”
t0“Soybean”
Claim · model-written summary
The mean yield increase or decrease at responsive sites was 400 kg ha −1.
- Taxon
- soybean
Glycine maxt0 - Outcome
- mean yield increase or decreasee0
- Value
- 400 kg ha −1e0
- Setting
- responsive sitese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The mean yield increase or decrease for responsive sites was 400 kg ha −1 .”
t0“Soybean”
Claim · model-written summary
The 3–8–15 fertilizer caused no leaf damage.
- Taxon
- soybeanGlycine maxt0
- Treatment
- 3–8–15 fertilizere0
- Outcome
- leaf damagee0
- Direction
- no leaf damagee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The 3–8–15 fertilizer caused no leaf damage and other fertilizers caused little or no damage”
t0“Soybean”
Claim · model-written summary
Other fertilizers caused little or no leaf damage.
- Taxon
- soybeanGlycine maxt0
- Treatment
- other fertilizerse0
- Outcome
- damagee0
- Direction
- little or no damagee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The 3–8–15 fertilizer caused no leaf damage and other fertilizers caused little or no damage”
t0“Soybean”
Claim · model-written summary
Leaf damage was not clearly related to yield decreases.
- Taxon
- soybeanGlycine maxt0
- Organ / stage
- damagee0
- Outcome
- yield decreasese0
- Qualifier
- not clearly relatede0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the damage was not clearly related with yield decreases”
t0“Soybean”
Claim · model-written summary
Foliar fertilization seldom increased tissue N–P–K composition, nutrient uptake, or photosynthesis at R2.
- Taxon
- soybeanGlycine maxt0
- Organ / stage
- R2 growth stagee0
- Treatment
- fertilizatione0
- Outcome
- tissue N–P–K composition, nutrient uptake, photosynthesise0
- Direction
- seldom increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fertilization seldom increased tissue N–P–K composition, nutrient uptake, photosynthesis, or plant weight measured at the R2 growth stage.”
t0“Soybean”
Claim · model-written summary
Foliar fertilization seldom increased plant weight at R2.
- Taxon
- soybeanGlycine maxt0
- Organ / stage
- R2 growth stagee0
- Treatment
- fertilizatione0
- Outcome
- plant weighte0
- Direction
- seldom increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fertilization seldom increased tissue N–P–K composition, nutrient uptake, photosynthesis, or plant weight measured at the R2 growth stage.”
t0“Soybean”
Claim · model-written summary
A combination of nutrient availability, vegetative growth, and rainfall explained 27% of variation in yield response.
- Taxon
- soybeanGlycine maxt0
- Organ / stage
- vegetative growthe0
- Outcome
- variation in yield responsee0
- Value
- 27%e0
- Qualifier
- N, P, and K availability, vegetative growth, and rainfalle0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“27% of the variation in yield response was explained by a combination of N, P, and K availability, vegetative growth, and rainfall.”
t0“Soybean”
Claim · model-written summary
Positive yield responses tended to occur when soil or weather reduced plant growth and nutrient availability.
- Taxon
- soybeanGlycine maxt0
- Outcome
- yield responsese0
- Direction
- Positivee0
- Qualifier
- tended to occure0
- Setting
- soil or weather conditionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Positive yield responses tended to occur when soil or weather conditions reduced plant growth and nutrient availability.”
t0“Soybean”
Claim · model-written summary
Foliar fertilization across all conditions will not offset application costs.
- Taxon
- soybeanGlycine maxt0
- Treatment
- Foliar fertilizatione0
- Outcome
- will not offset the application costse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Foliar fertilization across all conditions will not offset the application costs.”
t0“Soybean”
The same questions in other papers
fertilization · pest · Glycine max (soybean)Positive and negative results
25 papers in the same direction as this paper · 10 in the opposite direction
- negative
- negative
- negative
32 papers more in this group
See all 36 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.