Abstract
Abstract The effectiveness of ammonium nitrate, ammonium sulfate, calcium nitrate and urea for winter grown head lettuce ( Lactuca sativa L.) was evaluated. N source did not affect yield, quality factors, head size or total N accumulation. Applications of fertilizers containing NO 3 -N resulted in slightly higher NO 3 -N concentrations in the midribs. Plant growth and N accumulation were similar with all N sources at low temperatures. Air temperature below 13°C for a week or more sharply reduced N uptake and plant growth with all sources. About 80% of the total N is taken up by the plants in the 4 weeks before harvest. N source did not affect quality.
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Claims 7
Claim · model-written summary
Nitrogen source did not affect lettuce yield, quality, head size or total nitrogen accumulation.
- Taxon
- head lettucet0
- Treatment
- N sourcee0
- Outcome
- yield, quality factors, head sizee0
- Direction
- did not affecte0
Not reportedComparator
Verbatim
e0“N source did not affect yield, quality factors, head size or total N accumulation”
t0“head lettuce”
Claim · model-written summary
Nitrogen source did not affect total nitrogen accumulation.
Not reportedComparator
Verbatim
e0“N source did not affect yield, quality factors, head size or total N accumulation”
t0“head lettuce”
Claim · model-written summary
Nitrate fertilizers slightly increased midrib nitrate concentrations.
- Taxon
- head lettucet0
- Organ / stage
- midribse0
- Treatment
- fertilizers containing NO 3 -Ne0
- Outcome
- NO 3 -N concentrationse0
- Direction
- highere0
Not reportedComparator
Verbatim
e0“Applications of fertilizers containing NO 3 -N resulted in slightly higher NO 3 -N concentrations in the midribs”
t0“head lettuce”
Claim · model-written summary
Growth and nitrogen accumulation were similar across nitrogen sources at low temperature.
Verbatim
e0“Plant growth and N accumulation were similar with all N sources at low temperatures”
t0“head lettuce”
Claim · model-written summary
Air temperature below 13°C sharply reduced nitrogen uptake.
Verbatim
e0“Air temperature below 13°C for a week or more sharply reduced N uptake and plant growth with all sources”
t0“head lettuce”
Claim · model-written summary
Air temperature below 13°C sharply reduced plant growth.
Verbatim
e0“Air temperature below 13°C for a week or more sharply reduced N uptake and plant growth with all sources”
t0“head lettuce”
Claim · model-written summary
Plants take up about 80% of total nitrogen in four weeks before harvest.
Verbatim
e0“About 80% of the total N is taken up by the plants in the 4 weeks before harvest”
t0“head lettuce”