Abstract
Two greenhouse experiments were conducted to determine if application of humic substances to creeping bentgrass ( Agrostis stolonifera L.) turf would improve root mass, root length, or nutrient uptake. A commercially mined granular humate, a commercial liquid humic acid (HA), and liquid HAs extracted from leonardite, peat, and soil were applied to creeping bentgrass growing in either sand or solution culture and maintained at a height of 6 mm. Foliar applications included monthly or biweekly applications of HAs at 0, 100, 200, or 400 mg HA L −1 . In sand culture, humate incorporated to a depth of 10 cm stimulated a 45% increase in root mass at the 0‐ to 10‐cm depth and a 38% increase in root mass at the 10‐ to 20‐cm depth compared with the control. Incorporation of granular humate increased maximum root length 15% compared with non‐treated turf in sand culture. No foliar applied HA source consistently provided rooting superior to the control in either sand or solution culture. Nitrogen, Ca, Mg, and Fe uptake were relatively unaffected by humic substance application. The phosphorous concentration of plants in sand culture was increased 3 to 5% by incorporated humate and foliar application of soil, peat, or Leonardite‐derived HA. In solution culture, however, P uptake was unaffected by HA application. The lack of improved rooting or increased P uptake in solution culture supports the hypothesis that humic acids may have limited growth promoting effects on plants adequately supplied with nutrients.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. 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 10
Claim · model-written summary
Humate incorporated to 10 cm depth increased root mass by 45% compared with the control in sand culture.
- Taxon
- Creeping Bentgrass
Agrostis stoloniferat0 - Treatment
- humate incorporated to a depth of 10 cme0
- Outcome
- root masse0
- Direction
- increasee0
- Value
- 45%e0
- Comparator
- controle1
- Setting
- In sand culturee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Creeping Bentgrass”
e0“In sand culture, humate incorporated to a depth of 10 cm stimulated a 45% increase in root mass”
e1“compared with the control”
Claim · model-written summary
Humate incorporated to 10 cm depth increased root mass by 38% in the lower layer compared with the control in sand culture.
- Taxon
- Creeping BentgrassAgrostis stoloniferat0
- Treatment
- humate incorporated to a depth of 10 cme0
- Outcome
- root masse1
- Direction
- increasee1
- Value
- 38%e1
- Comparator
- controle2
- Setting
- In sand culturee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Creeping Bentgrass”
e0“In sand culture, humate incorporated to a depth of 10 cm stimulated a 45% increase in root mass”
e1“a 38% increase in root mass”
e2“compared with the control”
Claim · model-written summary
Granular humate increased maximum root length by 15% compared with non-treated turf in sand culture.
- Taxon
- Creeping BentgrassAgrostis stoloniferat0
- Treatment
- Incorporation of granular humatee0
- Outcome
- maximum root lengthe0
- Direction
- increasede0
- Value
- 15%e0
- Comparator
- non‐treated turfe0
- Setting
- in sand culturee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Creeping Bentgrass”
e0“Incorporation of granular humate increased maximum root length 15% compared with non‐treated turf in sand culture”
Claim · model-written summary
No foliar-applied humic acid source consistently gave rooting superior to the control in sand or solution culture.
- Taxon
- Creeping BentgrassAgrostis stoloniferat0
- Treatment
- foliar applied HA sourcee0
- Outcome
- rootinge0
- Direction
- superiore0
- Comparator
- controle0
- Setting
- either sand or solution culturee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Creeping Bentgrass”
e0“No foliar applied HA source consistently provided rooting superior to the control in either sand or solution culture”
Claim · model-written summary
Nitrogen, calcium and magnesium uptake were relatively unaffected by humic substance application.
- Taxon
- Creeping BentgrassAgrostis stoloniferat0
- Treatment
- humic substance applicatione0
- Outcome
- Nitrogen, Ca, Mge0
- Direction
- unaffectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Creeping Bentgrass”
e0“Nitrogen, Ca, Mg, and Fe uptake were relatively unaffected by humic substance application”
Claim · model-written summary
Iron uptake was relatively unaffected by humic substance application.
- Taxon
- Creeping BentgrassAgrostis stoloniferat0
- Treatment
- humic substance applicatione0
- Outcome
- Fe uptakee0
- Direction
- unaffectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Creeping Bentgrass”
e0“Nitrogen, Ca, Mg, and Fe uptake were relatively unaffected by humic substance application”
Claim · model-written summary
Incorporated humate increased plant phosphorus concentration by 3 to 5% in sand culture.
- Taxon
- Creeping BentgrassAgrostis stoloniferat0
- Treatment
- incorporated humatee0
- Outcome
- phosphorous concentratione0
- Direction
- increasede0
- Value
- 3 to 5%e0
- Setting
- in sand culturee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Creeping Bentgrass”
e0“The phosphorous concentration of plants in sand culture was increased 3 to 5% by incorporated humate”
Claim · model-written summary
Foliar application of soil, peat or Leonardite-derived humic acid increased plant phosphorus concentration by 3 to 5% in sand culture.
- Taxon
- Creeping BentgrassAgrostis stoloniferat0
- Treatment
- foliar application of soil, peat, or Leonardite‐derived HAe0
- Outcome
- phosphorous concentratione0
- Direction
- increasede0
- Value
- 3 to 5%e0
- Setting
- in sand culturee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Creeping Bentgrass”
e0“The phosphorous concentration of plants in sand culture was increased 3 to 5% by incorporated humate and foliar application of soil, peat, or Leonardite‐derived HA”
Claim · model-written summary
In solution culture, humic acid application did not change P uptake by creeping bentgrass.
- Taxon
- Creeping BentgrassAgrostis stoloniferat0
- Treatment
- HA applicatione0
- Outcome
- P uptakee0
- Direction
- unaffectede0
- Setting
- In solution culturee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Creeping Bentgrass”
e0“In solution culture, however, P uptake was unaffected by HA application”
Claim · model-written summary
Humic acids may have limited growth-promoting effects on creeping bentgrass plants adequately supplied with nutrients (hypothesis).
- Taxon
- Creeping BentgrassAgrostis stoloniferat0
- Treatment
- humic acidse0
- Outcome
- growth promoting effectse0
- Qualifier
- on plants adequately supplied with nutrientse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Creeping Bentgrass”
e0“The lack of improved rooting or increased P uptake in solution culture supports the hypothesis that humic acids may have limited growth promoting effects on plants adequately supplied with nutrients”
The same questions in other papers
other · growth · Agrostis stolonifera (creeping bent grass)Positive and negative results
4 in the opposite direction
- positive
- positive
- positive
1 paper more in this group
See all 5 papers →application · growth · Agrostis stolonifera (creeping bent grass)Positive and negative results
1 paper in the same direction as this paper · 4 in the opposite direction
- positive
- positive
- positive
2 papers more in this group
See all 6 papers →other · nutrient: content · Agrostis stolonifera (creeping bent grass)Positive and negative results
3 papers in the same direction as this paper · 2 in the opposite direction
- no effect
- no effect
- negative
2 papers more in this group
See all 6 papers →application · molecular: metabolites · Agrostis stolonifera (creeping bent grass)Results agree
1 paper in the same direction as this paper
- positive
other · molecular: metabolites · Agrostis stolonifera (creeping bent grass)Results agree
2 papers in the same direction as this paper
- positive
- positive
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.