Abstract
ABSTRACT The effect of humic substances on yield and nutrient uptake of grass, maize, potato and spinach was investigated in six field experiments and two pot experiments in a high input cropping system. The humic substances originating from leonardite formations in Canada were applied as liquid solution to the soil (Humifirst liquid) or as a solid incorporated in mineral fertilizers (Humifirst incorporated). Formal meta-analysis of the results of all executed experiments showed that the application of humic substances had an overall positive effect on dry matter yield of the crops and this effect was statistically significant for Humifirst incorporated. In the case of permanent grassland, humic substances promoted mainly the production of the first grass cut, which has the highest grass quality among all cuts during the growing season. Tuber production on the potato field trial showed a high response on the application of humic substances. Total potato yield increased with 13 and 17% for Humifirst liquid and Humifirst incorporated, respectively. The effect of humic substances on maize yield was limited, probably due to the rather high nutrient status of both soils. Finally, the formal meta-analysis showed a consequent increase in nitrogen and phosphorus uptake of all studied crops as well. The effect on potassium and magnesium uptake was also mainly positive, while sodium and calcium uptake were not affected in most of the experiments.
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Claims 10
Claim · model-written summary
Humic substances had an overall positive effect on dry matter yield of grass, maize, potato and spinach in the meta-analysis.
- Taxon
- grass, maize, potato and spinache0
- Treatment
- humic substancese1
- Outcome
- dry matter yielde1
- Direction
- increaseinferrede1
Not reportedComparator
Verbatim
e0“The effect of humic substances on yield and nutrient uptake of grass, maize, potato and spinach was investigated”
e1“the application of humic substances had an overall positive effect on dry matter yield of the crops”
Claim · model-written summary
The overall effect of Humifirst incorporated on dry matter yield was statistically significant.
Not reportedComparator
Verbatim
e0“The effect of humic substances on yield and nutrient uptake of grass, maize, potato and spinach was investigated”
e1“the application of humic substances had an overall positive effect on dry matter yield of the crops”
e2“this effect was statistically significant for Humifirst incorporated”
Claim · model-written summary
In permanent grassland, humic substances mainly promoted production of the first grass cut.
- Taxon
- grasse3
- Treatment
- humic substancese3
- Outcome
- production of the first grass cute3
- Direction
- promotede3
- Setting
- permanent grasslande3
Not reportedComparator
Verbatim
e3“In the case of permanent grassland, humic substances promoted mainly the production of the first grass cut”
Claim · model-written summary
Tuber production on the potato field trial showed a high response to humic substances.
- Taxon
- potato
Solanum tuberosume4 - Treatment
- application of humic substancese4
- Outcome
- Tuber productione4
- Direction
- increaseinferrede4
- Setting
- potato field triale4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Tuber production on the potato field trial showed a high response on the application of humic substances”
Claim · model-written summary
Total potato yield increased with Humifirst liquid (13%).
- Taxon
- potatoSolanum tuberosume5
- Treatment
- Humifirst liquide5
- Outcome
- Total potato yielde5
- Direction
- increasede5
- Value
- 13e5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“Total potato yield increased with 13 and 17% for Humifirst liquid and Humifirst incorporated, respectively”
Claim · model-written summary
Total potato yield increased with Humifirst incorporated (17%).
- Taxon
- potatoSolanum tuberosume5
- Treatment
- Humifirst incorporatede5
- Outcome
- Total potato yielde5
- Direction
- increasede5
- Value
- 17%e5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“Total potato yield increased with 13 and 17% for Humifirst liquid and Humifirst incorporated, respectively”
Claim · model-written summary
The effect of humic substances on maize yield was limited, probably due to the high nutrient status of both soils.
- Treatment
- humic substancese6
- Outcome
- maize yielde6
- Direction
- limitede6
- Qualifier
- probably due to the rather high nutrient status of both soilse6
Zea maysNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“The effect of humic substances on maize yield was limited, probably due to the rather high nutrient status of both soils”
Claim · model-written summary
Meta-analysis showed a consequent increase in nitrogen and phosphorus uptake of all studied crops.
- Taxon
- grass, maize, potato and spinache0
- Treatment
- humic substancese1
- Outcome
- nitrogen and phosphorus uptakee7
- Direction
- increasee7
Not reportedComparator
Verbatim
e0“The effect of humic substances on yield and nutrient uptake of grass, maize, potato and spinach was investigated”
e1“the application of humic substances had an overall positive effect on dry matter yield of the crops”
e7“the formal meta-analysis showed a consequent increase in nitrogen and phosphorus uptake of all studied crops as well. The effect on potassium and magnesium uptake was also mainly positive, while sodium and calcium uptake were not affected in most of the experiments”
Claim · model-written summary
The effect of humic substances on potassium and magnesium uptake was mainly positive.
- Taxon
- grass, maize, potato and spinache0
- Treatment
- humic substancese1
- Outcome
- potassium and magnesium uptakee7
- Direction
- mainly positivee7
Not reportedComparator
Verbatim
e0“The effect of humic substances on yield and nutrient uptake of grass, maize, potato and spinach was investigated”
e1“the application of humic substances had an overall positive effect on dry matter yield of the crops”
e7“the formal meta-analysis showed a consequent increase in nitrogen and phosphorus uptake of all studied crops as well. The effect on potassium and magnesium uptake was also mainly positive, while sodium and calcium uptake were not affected in most of the experiments”
Claim · model-written summary
Sodium and calcium uptake were not affected by humic substances in most experiments.
- Taxon
- grass, maize, potato and spinache0
- Treatment
- humic substancese1
- Outcome
- sodium and calcium uptakee7
- Direction
- not affectede7
- Qualifier
- in most of the experimentse7
Not reportedComparator
Verbatim
e0“The effect of humic substances on yield and nutrient uptake of grass, maize, potato and spinach was investigated”
e1“the application of humic substances had an overall positive effect on dry matter yield of the crops”
e7“the formal meta-analysis showed a consequent increase in nitrogen and phosphorus uptake of all studied crops as well. The effect on potassium and magnesium uptake was also mainly positive, while sodium and calcium uptake were not affected in most of the experiments”
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See all 253 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.