Abstract
Nitrogen (N) was applied over 4 years to 6-year-old lychee trees (Litchi chinensis Sonn. cv. Bengal) growing in subtropical Queensland (lat. 27¦S.) on a sandy loam soil (0-15 cm) with 2.8 mg nitrate-N/kg, to determine the effect of time of N application on leaf N concentration, vegetative growth, flowering, and yield. Applications of N (equivalent to 750 kg N/ha in year 4) were made after panicle emergence in July, after harvest in January, or split between the 2 periods. Control trees received no N. Leaf N concentrations in April-June were, on average, about 0.1% lower after a single N application in winter than application in summer or split applications. Leaf N concentrations in November-February were about 0.1% higher after winter or split N applications than after summer applications. Timing of fertiliser application had no affect on yield. It took 4 years without N fertiliser to show significant reductions in yield compared with fertilised trees. In year 4, yield increased from 20 to 60 kg/tree on individual pairs of trees as leaf N in August increased from 0.95 to 1.56%. Lower yields in control trees in year 4 were associated with poor leaf growth in the previous 2 years, and with lower concentrations of N in the panicles, leaves, twigs, and small branches, as well as lower chlorophyll concentrations and net CO2 assimilation after fruit set, compared with trees receiving N.
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Claims 7
Claim · model-written summary
Winter application yielded lower April-June leaf N than summer or split applications.
- Taxon
- lychee
Litchi chinensist0 - Treatment
- single N application in wintere0
- Outcome
- Leaf N concentrationse0
- Direction
- lowere0
- Value
- about 0.1%e0
- Comparator
- application in summer or split applicationse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Leaf N concentrations in April-June were, on average, about 0.1% lower after a single N application in winter than application in summer or split applications”
t0“lychee”
Claim · model-written summary
Winter or split application yielded higher November-February leaf N than summer application.
- Taxon
- lycheeLitchi chinensist0
- Treatment
- winter or split N applicationse0
- Outcome
- Leaf N concentrationse0
- Direction
- highere0
- Value
- about 0.1%e0
- Comparator
- summer applicationse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Leaf N concentrations in November-February were about 0.1% higher after winter or split N applications than after summer applications”
t0“lychee”
Claim · model-written summary
Fertilizer timing did not affect yield.
- Taxon
- lycheeLitchi chinensist0
- Treatment
- Timing of fertiliser applicatione0
- Outcome
- yielde0
- Direction
- no affecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Timing of fertiliser application had no affect on yield”
t0“lychee”
Claim · model-written summary
Four years without nitrogen reduced yield relative to fertilized trees.
- Taxon
- lycheeLitchi chinensist0
- Treatment
- 4 years without N fertilisere0
- Outcome
- yielde0
- Direction
- reductionse0
- Comparator
- fertilised treese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“It took 4 years without N fertiliser to show significant reductions in yield compared with fertilised trees”
t0“lychee”
Claim · model-written summary
Year-four yield rose from 20 to 60 kg/tree with increasing August leaf N.
- Taxon
- lycheeLitchi chinensist0
- Organ / stage
- leafe0
- Outcome
- yielde0
- Direction
- increasede0
- Value
- 20 to 60 kg/treee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In year 4, yield increased from 20 to 60 kg/tree on individual pairs of trees as leaf N in August increased from 0.95 to 1.56%”
t0“lychee”
Claim · model-written summary
Lower control-tree yields accompanied poor prior leaf growth and lower N in multiple organs.
- Taxon
- lycheeLitchi chinensist0
- Outcome
- Lower yieldse0
- Direction
- Lowere0
- Comparator
- control treese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lower yields in control trees in year 4 were associated with poor leaf growth in the previous 2 years, and with lower concentrations of N in the panicles, leaves, twigs, and small branches”
t0“lychee”
Claim · model-written summary
Lower control-tree yields accompanied lower chlorophyll and CO2 assimilation after fruit set.
- Taxon
- lycheeLitchi chinensist0
- Outcome
- chlorophyll concentrations and net CO2 assimilatione0
- Direction
- lowere0
- Comparator
- trees receiving Ne0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“lower chlorophyll concentrations and net CO2 assimilation after fruit set, compared with trees receiving N”
t0“lychee”
The same questions in other papers
fertilization · yield · Litchi chinensis (lychee)Positive and negative results
2 in the opposite direction
- 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.