Abstract
Glass-house experiments were carried out to study the effect of soil acidification, caused by the continuous use of ammonium sulphate, on the availability of soil phosphorus to citrus plants. The soils for the glass-house experiments were sampled in a tilled and a permanent sod treatment of a factorial field experiment, each at several levels of ammonium sulphate. Nitrogen levels in the soil were equalized by application of ammonium nitrate solutions. Growth and phosphorus uptake of lemon cuttings and orange seedlings were considerably better in soil from the no-ammonium sulphate plots than in soil from the high ammonium sulphate plots. Application of phosphate caused a marked increase in growth and phosphorus uptake only of plants grown in soil from the no-nitrogen plots. Increasing levels of superphosphate had very little effect if applied to the soil from the high ammonium sulphate plots. A considerably better response to superphosphate was obtained if applied to soil from limed plots, or applied together with a mixture of calcium and magnesium silicate. A good response was also obtained to crushed rock phosphate. Analysis of soils indicated that in the acid, high ammonium sulphate soil a greater proportion of soil phosphorus was present as aluminium phosphate than in the no-ammonium sulphate soil. The results are discussed in relation to citrus fertilizer practices and their effect on fruit quality aspects.
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Claims 8
Claim · model-written summary
Lemon cuttings grew and took up phosphorus better in soil without ammonium sulphate than in high-ammonium-sulphate soil.
- Taxon
- lemon
Citrus ×limone0 - Organ / stage
- cuttingse0
- Treatment
- soil from the no-ammonium sulphate plotse0
- Outcome
- Growth and phosphorus uptakee0
- Direction
- considerably bettere0
- Comparator
- soil from the high ammonium sulphate plotse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Growth and phosphorus uptake of lemon cuttings and orange seedlings were considerably better in soil from the no-ammonium sulphate plots than in soil from the high ammonium sulphate plots.”
Claim · model-written summary
Orange seedlings grew and took up phosphorus better in soil without ammonium sulphate than in high-ammonium-sulphate soil.
Verbatim
e0“Growth and phosphorus uptake of lemon cuttings and orange seedlings were considerably better in soil from the no-ammonium sulphate plots than in soil from the high ammonium sulphate plots.”
Claim · model-written summary
Phosphate increased citrus growth and phosphorus uptake only in soil from no-nitrogen plots.
- Treatment
- Application of phosphatee0
- Outcome
- growth and phosphorus uptakee0
- Direction
- marked increasee0
- Qualifier
- only of plants grown in soil from the no-nitrogen plotse0
CitrusNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Application of phosphate caused a marked increase in growth and phosphorus uptake only of plants grown in soil from the no-nitrogen plots.”
t0“citrus”
Claim · model-written summary
Increasing superphosphate had very little effect in high-ammonium-sulphate soil.
- Treatment
- Increasing levels of superphosphatee0
- Outcome
- very little effecte0
- Qualifier
- soil from the high ammonium sulphate plotse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increasing levels of superphosphate had very little effect if applied to the soil from the high ammonium sulphate plots.”
t0“citrus”
Claim · model-written summary
Superphosphate elicited a better response in soil from limed plots.
- Treatment
- superphosphatee0
- Outcome
- response to superphosphatee0
- Direction
- considerably bettere0
- Qualifier
- soil from limed plotse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A considerably better response to superphosphate was obtained if applied to soil from limed plots, or applied together with a mixture of calcium and magnesium silicate.”
t0“citrus”
Claim · model-written summary
Superphosphate combined with calcium and magnesium silicate elicited a better response.
- Treatment
- superphosphatee0
- Outcome
- response to superphosphatee0
- Direction
- considerably bettere0
- Qualifier
- a mixture of calcium and magnesium silicatee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A considerably better response to superphosphate was obtained if applied to soil from limed plots, or applied together with a mixture of calcium and magnesium silicate.”
t0“citrus”
Claim · model-written summary
Crushed rock phosphate elicited a good response.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A good response was also obtained to crushed rock phosphate.”
t0“citrus”
Claim · model-written summary
Acid, high-ammonium-sulphate soil contained a greater proportion of phosphorus as aluminium phosphate than soil without ammonium sulphate.
- Outcome
- proportion of soil phosphorus was present as aluminium phosphatee0
- Direction
- greatere0
- Comparator
- the no-ammonium sulphate soile0
- Setting
- acid, high ammonium sulphate soile0
Not reportedTaxon
Verbatim
e0“Analysis of soils indicated that in the acid, high ammonium sulphate soil a greater proportion of soil phosphorus was present as aluminium phosphate than in the no-ammonium sulphate soil.”
The same questions in other papers
sulfate · growth · Citrus sinensis (sweet orange)Results agree
1 paper in the same direction as this paper
- positive
phosphorus · growth · CitrusResults differ
5 papers in the same direction as this paper · 2 in the opposite direction
- no effect
- negative
- positive
4 papers more in this group
See all 8 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.