Abstract
SummaryBench-grafted Fuji/M.26 trees were fertigated with one of seven nitrogen concentrations (0, 2.5, 5, 7.5, 10, 15 or 20 mM), using a modified Hoagland’s solution from 30 June to 1 September. In mid-October, plants in each N treatment were randomly divided into three groups. One group was sampled destructively to determine background tree N status before foliar urea applications. The second was painted with a 3% 15N-enriched urea solution twice, at weekly intervals, on both sides of all leaves. The third group served as the control. All the fallen leaves from both the 15N-treated and the control trees were collected during leaf abscission. The trees were harvested at the end of natural leaf fall. Nitrogen fertigation during the growing season resulted in a wide range of tree N status, as indicated by leaf N (1.3–3.5.g m–2) in the autumn. The percentage of N partitioned into the foliage increased linearly with increasing leaf N content up to 2.2 g m–2, then reached a plateau of 50–55% with further rise in leaf N. 15N uptake and mobilization per unit leaf area and the percentage of 15N mobilized from the leaves decreased with increasing leaf N content. Of the 15N mobilized back to the tree, the percentage of 15N partitioned into the root system decreased with increasing tree N status. For the control trees, N mobilization per unit leaf area increased with increasing leaf N up to 3 g m–2, then levelled off with any further increase in N content. The percentage of N mobilization remained at approximately 60% until leaf N reached 3 g m–2, then declined with a further increase in leaf N content. Foliar 15N-urea applications reduced mobilization of endogenous leaf N regardless of tree N status. On a whole-tree basis, foliar 15N-urea applications increased the total amount of N across N fertigation treatments. We conclude that trees with low N status are more efficient in absorbing and mobilizing N from foliar urea than those with high N status. Likewise, more N derived from foliar urea is partitioned into the root systems of low N trees than of high N trees.
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 13
Claim · model-written summary
Nitrogen fertigation produced a wide range of autumn tree nitrogen status.
- Taxon
- apple
Malus domesticat0 - Treatment
- Nitrogen fertigatione0
- Outcome
- tree N statuse0
- Value
- 1.3–3.5.g m–2e0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen fertigation during the growing season resulted in a wide range of tree N status, as indicated by leaf N (1.3–3.5.g m–2) in the autumn”
t0“apple”
Claim · model-written summary
The foliage partition of nitrogen rose with leaf nitrogen up to 2.2 g m–2 and plateaued at 50–55%.
- Taxon
- appleMalus domesticat0
- Organ / stage
- foliagee0
- Outcome
- percentage of N partitioned into the foliagee0
- Direction
- increasede0
- Value
- 50–55%e0
- Qualifier
- up to 2.2 g m–2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The percentage of N partitioned into the foliage increased linearly with increasing leaf N content up to 2.2 g m–2, then reached a plateau of 50–55%”
t0“apple”
Claim · model-written summary
15N uptake per leaf area decreased with rising leaf nitrogen.
- Taxon
- appleMalus domesticat0
- Organ / stage
- leafe0
- Outcome
- 15N uptakee0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“15N uptake and mobilization per unit leaf area and the percentage of 15N mobilized from the leaves decreased with increasing leaf N content”
t0“apple”
Claim · model-written summary
15N mobilization per leaf area decreased with rising leaf nitrogen.
- Taxon
- appleMalus domesticat0
- Organ / stage
- leafe0
- Outcome
- mobilization per unit leaf areae0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“15N uptake and mobilization per unit leaf area and the percentage of 15N mobilized from the leaves decreased with increasing leaf N content”
t0“apple”
Claim · model-written summary
The percentage of leaf 15N mobilized decreased with rising leaf nitrogen.
- Taxon
- appleMalus domesticat0
- Organ / stage
- leavese0
- Outcome
- percentage of 15N mobilized from the leavese0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the percentage of 15N mobilized from the leaves decreased with increasing leaf N content”
t0“apple”
Claim · model-written summary
The root share of mobilized 15N decreased as tree nitrogen status rose.
- Taxon
- appleMalus domesticat0
- Organ / stage
- root systeme0
- Outcome
- percentage of 15N partitioned into the root systeme0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the percentage of 15N partitioned into the root system decreased with increasing tree N status”
t0“apple”
Claim · model-written summary
Control tree leaf nitrogen mobilization per area increased to 3 g m–2 leaf nitrogen, then levelled off.
- Taxon
- appleMalus domesticat0
- Organ / stage
- leafe0
- Outcome
- N mobilization per unit leaf areae0
- Direction
- increasede0
- Qualifier
- up to 3 g m–2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“N mobilization per unit leaf area increased with increasing leaf N up to 3 g m–2, then levelled off with any further increase in N content”
t0“apple”
Claim · model-written summary
Control tree percentage nitrogen mobilization stayed near 60% until leaf nitrogen reached 3 g m–2.
- Taxon
- appleMalus domesticat0
- Organ / stage
- leafe0
- Outcome
- percentage of N mobilizatione0
- Direction
- remainede0
- Value
- approximately 60%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The percentage of N mobilization remained at approximately 60% until leaf N reached 3 g m–2”
t0“apple”
Claim · model-written summary
Control tree percentage nitrogen mobilization declined above 3 g m–2 leaf nitrogen.
- Taxon
- appleMalus domesticat0
- Organ / stage
- leafe0
- Outcome
- percentage of N mobilizatione1
- Direction
- declinede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“then declined with a further increase in leaf N content”
e1“The percentage of N mobilization”
t0“apple”
Claim · model-written summary
Foliar 15N-urea reduced endogenous leaf nitrogen mobilization across tree nitrogen levels.
- Taxon
- appleMalus domesticat0
- Treatment
- Foliar 15N-urea applicationse0
- Outcome
- mobilization of endogenous leaf Ne0
- Direction
- reducede0
- Qualifier
- regardless of tree N statuse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Foliar 15N-urea applications reduced mobilization of endogenous leaf N regardless of tree N status”
t0“apple”
Claim · model-written summary
Foliar 15N-urea increased whole-tree total nitrogen across fertigation treatments.
- Taxon
- appleMalus domesticat0
- Treatment
- foliar 15N-urea applicationse0
- Outcome
- total amount of Ne0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“foliar 15N-urea applications increased the total amount of N across N fertigation treatments”
t0“apple”
Claim · model-written summary
Low nitrogen trees absorbed and mobilized more nitrogen from foliar urea than high nitrogen trees.
- Taxon
- appleMalus domesticat0
- Outcome
- absorbing and mobilizing N from foliar ureae0
- Direction
- more efficiente0
- Comparator
- those with high N statuse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“trees with low N status are more efficient in absorbing and mobilizing N from foliar urea than those with high N status”
t0“apple”
Claim · model-written summary
Low nitrogen trees partitioned more foliar urea nitrogen to roots than high nitrogen trees.
- Taxon
- appleMalus domesticat0
- Outcome
- N derived from foliar urea is partitioned into the root systemse0
- Direction
- moree0
- Comparator
- high N treese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“more N derived from foliar urea is partitioned into the root systems of low N trees than of high N trees”
t0“apple”
The same questions in other papers
application · nutrient: content · Malus domestica (apple)Positive and negative results
15 papers in the same direction as this paper · 100 in the opposite direction
- positive
- positive
- positive
112 papers more in this group
See all 116 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.