Abstract
SUMMARY Results at harvesting are described of two comprehensive NPK fertilizer experiments with E. grandis on sites previously under wattle in the Natal Midlands. The experimental sites differ considerably in respect of physiography, climate, and soil. The difference in climate and soil are clearly evident from the respective analyses of soil samples from the sites, one soil of a dystrophic series belonging to the Griffin form, and the other a mesotrophic series of the Hutton form. Except in one instance, nitrogen application showed no significant response, which is expected on these nitrogen-enriched soils of old wattle plantations. There is a tendency, which in one instance was significant, that nitrogen has a depressive effect on E. grandis, but this is ascribed to burning the transplants when the fertilizer is too concentrated and applied too close to the trees. Superphosphate application on these sites gives highly profitable results, the additional net profit per ha being nearly R400 on the better site and at least R35 on the poorer site. The optimum application rate on the better site is not more than 130 g superphosphate (8,3% P) per tree, while the optimum rate on the poorer site might be as high as 260 g. Significant responses to potash application are limited to mesotrophic soils and are of a curvilinear nature. This last phenomenon especially is difficult to explain, but is known to have occurred elsewhere.
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Claims 8
Claim · model-written summary
Nitrogen application generally showed no significant response.
- Taxon
- Eucalyptus grandis
Eucalyptus grandist0 - Treatment
- nitrogen applicatione0
- Outcome
- responsee0
- Direction
- no significant responsee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Except in one instance, nitrogen application showed no significant response, which is expected on these nitrogen-enriched soils of old wattle plantations.”
t0“Eucalyptus grandis”
Claim · model-written summary
Nitrogen tended to depress Eucalyptus, significantly in one instance.
- Taxon
- E. grandisEucalyptus grandise0
- Treatment
- nitrogene0
- Outcome
- E. grandise0
- Direction
- depressive effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There is a tendency, which in one instance was significant, that nitrogen has a depressive effect on E. grandis, but this is ascribed to burning the transplants when the fertilizer is too concentrated and applied too close to the trees.”
Claim · model-written summary
The authors attribute the depressive nitrogen response to transplant burning from concentrated fertilizer placed too close.
- Taxon
- Eucalyptus grandisEucalyptus grandist0
- Treatment
- fertilizere0
- Outcome
- burning the transplantse0
- Qualifier
- too concentrated and applied too close to the treese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“but this is ascribed to burning the transplants when the fertilizer is too concentrated and applied too close to the trees.”
t0“Eucalyptus grandis”
Claim · model-written summary
Superphosphate increased net profit by nearly R400 per hectare on the better site.
- Taxon
- Eucalyptus grandisEucalyptus grandist0
- Treatment
- Superphosphate applicatione0
- Outcome
- additional net profit per hae0
- Direction
- additionale0
- Value
- nearly R400e0
- Setting
- better sitee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Superphosphate application on these sites gives highly profitable results, the additional net profit per ha being nearly R400 on the better site and at least R35 on the poorer site.”
t0“Eucalyptus grandis”
Claim · model-written summary
Superphosphate increased net profit by at least R35 per hectare on the poorer site.
- Taxon
- Eucalyptus grandisEucalyptus grandist0
- Treatment
- Superphosphate applicatione0
- Outcome
- additional net profit per hae0
- Direction
- additionale0
- Value
- at least R35e0
- Setting
- poorer sitee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Superphosphate application on these sites gives highly profitable results, the additional net profit per ha being nearly R400 on the better site and at least R35 on the poorer site.”
t0“Eucalyptus grandis”
Claim · model-written summary
The optimum superphosphate rate on the better site was no more than 130 g per tree.
- Taxon
- Eucalyptus grandisEucalyptus grandist0
- Outcome
- optimum application ratee0
- Direction
- not more thane0
- Value
- 130 g superphosphate (8,3% P) per treee0
- Setting
- better sitee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The optimum application rate on the better site is not more than 130 g superphosphate (8,3% P) per tree, while the optimum rate on the poorer site might be as high as 260 g.”
t0“Eucalyptus grandis”
Claim · model-written summary
The optimum superphosphate rate on the poorer site might reach 260 g.
- Taxon
- Eucalyptus grandisEucalyptus grandist0
- Outcome
- optimum ratee0
- Direction
- as high ase0
- Value
- 260 ge0
- Setting
- poorer sitee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The optimum application rate on the better site is not more than 130 g superphosphate (8,3% P) per tree, while the optimum rate on the poorer site might be as high as 260 g.”
t0“Eucalyptus grandis”
Claim · model-written summary
Potash gave significant curvilinear responses only on mesotrophic soils.
- Taxon
- Eucalyptus grandisEucalyptus grandist0
- Treatment
- potash applicatione0
- Outcome
- responsese0
- Qualifier
- curvilinear naturee0
- Setting
- mesotrophic soilse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Significant responses to potash application are limited to mesotrophic soils and are of a curvilinear nature.”
t0“Eucalyptus grandis”
The same questions in other papers
phosphorus · yield · Eucalyptus grandis (rose gum)Results agree
1 paper in the same direction as this paper
- 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.