Abstract
Lettuce is one of the leading vegetables in Brazil. However, studies concerning its fertilization for the Northeastern region of the country are still scarce. This work was carried out to evaluate the effects of mineral Nitrogen supply and organic fertilization on the production and nitrate accumulation in lettuce, cultivar Elba, in the semi-arid zone of Paraíba, Brazil. A randomized block design, with four replications, was used to test five doses of cattle manure (30; 60; 90; 120, and 150 t ha-1), five doses of N supplied as urea (30; 60; 90; 120, and 150 kg ha-1), and a control without fertilization. Along with mineral N, the other nutrients were also supplied using mineral sources. No additional nutrients were supplied where organic fertilization was used. Lettuce yield was significantly higher when organic fertilization was used, compared to the mineral nutrient supply. Taking into account most of the fertilization doses recommended for growing lettuce in the Brazilian Northeastern States, N mineral fertilization in sandy soils with low organic matter contents can be fully replaced by organic fertilization with cattle manure. Plant total (PTY) and commercial yield (PCY) as affected by the mineral N supply fitted into a quadratic model, in which the doses 94.5 and 95.7 kg ha-1 corresponded to respectively the highest PTY (381.9 g plant-1) and PCY (321.6 g plant-1). Where organic fertilization was used, PTY and PCY fitted into a linear model. Therefore, the highest PTY (523.9 g plant-1) and PCY (449.48 g plant-1) were observed at the highest manure doses. Nitrate content on roots, stems, and leaves increased linearly with Nitrogen and manure application. In roots, the nitrate content (mg kg-1 of fresh matter) reached 93.96 (N mineral (Nm)) and 65.09 (organic fertilization (OF)); in stems, 183.45 (Nm) and 98.22 (OF); and in leaves, 121.98 (Nm) and 75.62 (OF). The maximum nitrate content observed in leaves was far below the risk level for human health.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by-nc. 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 14
Claim · model-written summary
Lettuce yield was higher under organic fertilization than under mineral nutrient supply.
- Taxon
- Lettuce
Lactuca sativae1 - Treatment
- organic fertilizatione1
- Outcome
- Lettuce yielde1
- Direction
- highere1
- Comparator
- mineral nutrient supplye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Lettuce yield was significantly higher when organic fertilization was used, compared to the mineral nutrient supply”
Claim · model-written summary
N mineral fertilization in sandy soils with low organic matter can be fully replaced by cattle manure for lettuce in the Brazilian Northeast.
- Taxon
- lettuceLactuca sativae0
- Outcome
- N mineral fertilization in sandy soils with low organic matter contents can be fully replaced by organic fertilization with cattle manuree0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Taking into account most of the fertilization doses recommended for growing lettuce in the Brazilian Northeastern States, N mineral fertilization in sandy soils with low organic matter contents can be fully replaced by organic fertilization with cattle manure”
Claim · model-written summary
Under mineral N supply, plant total yield (PTY) was highest at 94.5 kg ha-1 in the quadratic fit, at 381.9 g plant-1.
- Taxon
- LettuceLactuca sativae0
- Treatment
- mineral N supplye2
- Outcome
- Plant total (PTY)e2
- Direction
- higheste2
- Value
- 381.9 g plant-1e2
- Qualifier
- doses 94.5 and 95.7 kg ha-1e2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lettuce is one of the leading vegetables in Brazil”
e2“Plant total (PTY) and commercial yield (PCY) as affected by the mineral N supply fitted into a quadratic model, in which the doses 94.5 and 95.7 kg ha-1 corresponded to respectively the highest PTY (381.9 g plant-1) and PCY (321.6 g plant-1)”
Claim · model-written summary
Under mineral N supply, commercial yield (PCY) was highest at 95.7 kg ha-1 in the quadratic fit, at 321.6 g plant-1.
- Taxon
- LettuceLactuca sativae0
- Treatment
- mineral N supplye2
- Outcome
- commercial yield (PCY)e2
- Direction
- higheste2
- Value
- 321.6 g plant-1e2
- Qualifier
- doses 94.5 and 95.7 kg ha-1e2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lettuce is one of the leading vegetables in Brazil”
e2“Plant total (PTY) and commercial yield (PCY) as affected by the mineral N supply fitted into a quadratic model, in which the doses 94.5 and 95.7 kg ha-1 corresponded to respectively the highest PTY (381.9 g plant-1) and PCY (321.6 g plant-1)”
Claim · model-written summary
Under organic fertilization, plant total yield (PTY) was highest at the highest manure doses, at 523.9 g plant-1.
- Taxon
- LettuceLactuca sativae0
- Treatment
- highest manure dosese3
- Outcome
- PTYe3
- Direction
- higheste3
- Value
- 523.9 g plant-1e3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lettuce is one of the leading vegetables in Brazil”
e3“Therefore, the highest PTY (523.9 g plant-1) and PCY (449.48 g plant-1) were observed at the highest manure doses”
Claim · model-written summary
Under organic fertilization, commercial yield (PCY) was highest at the highest manure doses, at 449.48 g plant-1.
- Taxon
- LettuceLactuca sativae0
- Treatment
- highest manure dosese3
- Outcome
- PCYe3
- Direction
- higheste3
- Value
- 449.48 g plant-1e3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lettuce is one of the leading vegetables in Brazil”
e3“Therefore, the highest PTY (523.9 g plant-1) and PCY (449.48 g plant-1) were observed at the highest manure doses”
Claim · model-written summary
Nitrate content in lettuce roots, stems and leaves increased linearly with nitrogen and manure application.
- Taxon
- LettuceLactuca sativae0
- Organ / stage
- roots, stems, and leavese4
- Treatment
- Nitrogen and manure applicatione4
- Outcome
- Nitrate contente4
- Direction
- increasede4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lettuce is one of the leading vegetables in Brazil”
e4“Nitrate content on roots, stems, and leaves increased linearly with Nitrogen and manure application”
Claim · model-written summary
Lettuce root nitrate content reached 93.96 mg kg-1 fresh matter under N mineral supply.
- Taxon
- LettuceLactuca sativae0
- Organ / stage
- rootse5
- Treatment
- N mineral (Nm)e5
- Outcome
- nitrate contente5
- Value
- 93.96e5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lettuce is one of the leading vegetables in Brazil”
e5“In roots, the nitrate content (mg kg-1 of fresh matter) reached 93.96 (N mineral (Nm)) and 65.09 (organic fertilization (OF))”
Claim · model-written summary
Lettuce root nitrate content reached 65.09 mg kg-1 fresh matter under organic fertilization.
- Taxon
- LettuceLactuca sativae0
- Organ / stage
- rootse5
- Treatment
- organic fertilization (OF)e5
- Outcome
- nitrate contente5
- Value
- 65.09e5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lettuce is one of the leading vegetables in Brazil”
e5“In roots, the nitrate content (mg kg-1 of fresh matter) reached 93.96 (N mineral (Nm)) and 65.09 (organic fertilization (OF))”
Claim · model-written summary
Lettuce stem nitrate content reached 183.45 mg kg-1 fresh matter under N mineral supply.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lettuce is one of the leading vegetables in Brazil”
e4“Nitrate content on roots, stems, and leaves increased linearly with Nitrogen and manure application”
e6“in stems, 183.45 (Nm) and 98.22 (OF)”
Claim · model-written summary
Lettuce stem nitrate content reached 98.22 mg kg-1 fresh matter under organic fertilization.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lettuce is one of the leading vegetables in Brazil”
e4“Nitrate content on roots, stems, and leaves increased linearly with Nitrogen and manure application”
e6“in stems, 183.45 (Nm) and 98.22 (OF)”
Claim · model-written summary
Lettuce leaf nitrate content reached 121.98 mg kg-1 fresh matter under N mineral supply.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lettuce is one of the leading vegetables in Brazil”
e4“Nitrate content on roots, stems, and leaves increased linearly with Nitrogen and manure application”
e7“in leaves, 121.98 (Nm) and 75.62 (OF)”
Claim · model-written summary
Lettuce leaf nitrate content reached 75.62 mg kg-1 fresh matter under organic fertilization.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lettuce is one of the leading vegetables in Brazil”
e4“Nitrate content on roots, stems, and leaves increased linearly with Nitrogen and manure application”
e7“in leaves, 121.98 (Nm) and 75.62 (OF)”
Claim · model-written summary
The maximum leaf nitrate content of lettuce was far below the risk level for human health.
- Taxon
- LettuceLactuca sativae0
- Organ / stage
- leavese1
- Outcome
- maximum nitrate content observed in leavese1
- Qualifier
- far belowe1
- Comparator
- risk level for human healthe1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lettuce is one of the leading vegetables in Brazil”
e1“The maximum nitrate content observed in leaves was far below the risk level for human health”
The same questions in other papers
fertilization · yield · Lactuca sativa (garden lettuce)Positive and negative results
212 papers in the same direction as this paper · 34 in the opposite direction · 2 reporting no difference from an alternative
- positive
- positive
- positive
245 papers more in this group
See all 249 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.