Abstract
Introduction Zinc (Zn) deficiency is a major limiting factor for crop productivity, particularly in sandy soils where nutrient retention and bioavailability are poor. The field experiment was conducted at the Agricultural Experimental Station, Cairo University (Giza, Egypt) during the 2022–2024 winter seasons. This study aimed to analyze the spectral responses of faba bean (Vicia faba L.) under different foliar Zn concentrations (0, 0.5, 1.0, 1.5, and 2.0 g L −1 ZnSO 4 ·7H 2 O) using a Randomized Complete Block Design (RCBD) with three replications, and to identify vegetation indices sensitive to Zn nutrition. Methods Growth traits, biochemical attributes, seed yield, hyperspectral reflectance, and soil spectral properties were integrated to establish robust vegetation–soil indicators. Results and discussion Foliar Zn application increased chlorophyll content by 24.5%, protein by 18.3%, and seed yield by 27.6% compared with the control (p ≤ 0.05). Results revealed that foliar Zn application significantly enhanced chlorophyll content, protein accumulation, soluble sugars, and seed yield, with the optimum response observed at 2.0 g L −1 . Spectral signatures demonstrated that Zn enrichment decreased red reflectance (∼670 nm), sharpened the red-edge slope (700–750 nm), and increased near-infrared reflectance (∼800 nm), indicating improved canopy structure and photosynthetic activity. Vegetation indices such as Normalized Difference Vegetation Index (NDVI), Green NDVI (GNDVI), Photochemical Reflectance Index (PRI), Normalized Difference Red-Edge Index (NDRE), Red-Edge Position (REP), and Modified Chlorophyll Absorption Ratio Index (MCARI) were highly responsive to Zn levels, showing strong correlations with physiological traits and closely aligned with growth and yield performance. Soil-based spectral indices, including the Clay Ratio Index (CRI) and the Normalized Difference Soil Index (NDSI), also differentiated among soil samples, linking soil spectral features with Zn-associated crop responses. These findings confirm that hyperspectral reflectance and derived indices provide reliable, non-destructive tools for monitoring Zn nutrition in faba bean. The integration of spectral traits with agronomic and biochemical data emphasizes the potential of hyperspectral sensing for optimizing micronutrient management in sandy soils. Moreover, the outcomes highlight the role of hyperspectral tools in precision agriculture, enabling site-specific nutrient strategies that enhance productivity, resource-use efficiency, and sustainable food security.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. 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 11
Claim · model-written summary
Foliar Zn application increased chlorophyll content by 24.5% compared with the control.
- Taxon
- faba bean
Vicia fabat0 - Treatment
- Foliar Zn applicatione1
- Outcome
- chlorophyll contente1
- Direction
- increasede1
- Value
- 24.5%e1
- Qualifier
- p ≤ 0.05e1
- Comparator
- controle1
- Setting
- Agricultural Experimental Station, Cairo University (Giza, Egypt)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“faba bean plants”
e0“The field experiment was conducted at the Agricultural Experimental Station, Cairo University (Giza, Egypt) during the 2022–2024 winter seasons”
e1“Foliar Zn application increased chlorophyll content by 24.5%, protein by 18.3%, and seed yield by 27.6% compared with the control (p ≤ 0.05)”
Claim · model-written summary
Foliar Zn application increased protein content by 18.3% compared with the control.
- Taxon
- faba beanVicia fabat0
- Treatment
- Foliar Zn applicatione1
- Outcome
- proteine1
- Direction
- increasede1
- Value
- 18.3%e1
- Qualifier
- p ≤ 0.05e1
- Comparator
- controle1
- Setting
- Agricultural Experimental Station, Cairo University (Giza, Egypt)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“faba bean plants”
e0“The field experiment was conducted at the Agricultural Experimental Station, Cairo University (Giza, Egypt) during the 2022–2024 winter seasons”
e1“Foliar Zn application increased chlorophyll content by 24.5%, protein by 18.3%, and seed yield by 27.6% compared with the control (p ≤ 0.05)”
Claim · model-written summary
Foliar Zn application increased seed yield by 27.6% compared with the control.
- Taxon
- faba beanVicia fabat0
- Treatment
- Foliar Zn applicatione1
- Outcome
- seed yielde1
- Direction
- increasede1
- Value
- 27.6%e1
- Qualifier
- p ≤ 0.05e1
- Comparator
- controle1
- Setting
- Agricultural Experimental Station, Cairo University (Giza, Egypt)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“faba bean plants”
e0“The field experiment was conducted at the Agricultural Experimental Station, Cairo University (Giza, Egypt) during the 2022–2024 winter seasons”
e1“Foliar Zn application increased chlorophyll content by 24.5%, protein by 18.3%, and seed yield by 27.6% compared with the control (p ≤ 0.05)”
Claim · model-written summary
The optimum response to foliar Zn was observed at 2.0 g L −1.
- Taxon
- faba beanVicia fabat0
- Outcome
- optimum responsee2
- Value
- 2.0 g L −1e2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“faba bean plants”
e2“Results revealed that foliar Zn application significantly enhanced chlorophyll content, protein accumulation, soluble sugars, and seed yield, with the optimum response observed at 2.0 g L −1”
Claim · model-written summary
Foliar Zn application significantly enhanced soluble sugars.
- Taxon
- faba beanVicia fabat0
- Treatment
- Foliar Zn applicatione2
- Outcome
- soluble sugarse2
- Direction
- enhancede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“faba bean plants”
e2“Results revealed that foliar Zn application significantly enhanced chlorophyll content, protein accumulation, soluble sugars, and seed yield, with the optimum response observed at 2.0 g L −1”
Claim · model-written summary
Zn enrichment decreased red reflectance (∼670 nm).
- Taxon
- faba beanVicia fabat0
- Treatment
- Zn enrichmente3
- Outcome
- red reflectance (∼670 nm)e3
- Direction
- decreasede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“faba bean plants”
e3“Spectral signatures demonstrated that Zn enrichment decreased red reflectance (∼670 nm), sharpened the red-edge slope (700–750 nm), and increased near-infrared reflectance (∼800 nm)”
Claim · model-written summary
Zn enrichment sharpened the red-edge slope (700–750 nm).
- Taxon
- faba beanVicia fabat0
- Treatment
- Zn enrichmente3
- Outcome
- red-edge slope (700–750 nm)e3
- Direction
- sharpenede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“faba bean plants”
e3“Spectral signatures demonstrated that Zn enrichment decreased red reflectance (∼670 nm), sharpened the red-edge slope (700–750 nm), and increased near-infrared reflectance (∼800 nm)”
Claim · model-written summary
Zn enrichment increased near-infrared reflectance (∼800 nm).
- Taxon
- faba beanVicia fabat0
- Treatment
- Zn enrichmente3
- Outcome
- near-infrared reflectance (∼800 nm)e3
- Direction
- increasede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“faba bean plants”
e3“Spectral signatures demonstrated that Zn enrichment decreased red reflectance (∼670 nm), sharpened the red-edge slope (700–750 nm), and increased near-infrared reflectance (∼800 nm)”
Claim · model-written summary
Vegetation indices were highly responsive to Zn levels.
- Taxon
- faba beanVicia fabat0
- Outcome
- Vegetation indicese4
- Qualifier
- highly responsive to Zn levelse4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“faba bean plants”
e4“Vegetation indices such as Normalized Difference Vegetation Index (NDVI), Green NDVI (GNDVI), Photochemical Reflectance Index (PRI), Normalized Difference Red-Edge Index (NDRE), Red-Edge Position (REP), and Modified Chlorophyll Absorption Ratio Index (MCARI) were highly responsive to Zn levels”
Claim · model-written summary
Vegetation indices showed strong correlations with physiological traits.
- Taxon
- faba beanVicia fabat0
- Outcome
- Vegetation indicese4
- Qualifier
- showing strong correlations with physiological traitse5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“faba bean plants”
e4“Vegetation indices such as Normalized Difference Vegetation Index (NDVI), Green NDVI (GNDVI), Photochemical Reflectance Index (PRI), Normalized Difference Red-Edge Index (NDRE), Red-Edge Position (REP), and Modified Chlorophyll Absorption Ratio Index (MCARI) were highly responsive to Zn levels”
e5“showing strong correlations with physiological traits”
Claim · model-written summary
Soil-based spectral indices differentiated among soil samples.
- Taxon
- faba beanVicia fabat0
- Outcome
- Soil-based spectral indicese6
- Qualifier
- differentiated among soil samplese6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“faba bean plants”
e6“Soil-based spectral indices, including the Clay Ratio Index (CRI) and the Normalized Difference Soil Index (NDSI), also differentiated among soil samples”
The same questions in other papers
zinc atom · physiology: pigments · Vicia faba (faba bean)Results differ
3 papers in the same direction as this paper · 3 in the opposite direction
- negative
- negative
- negative
3 papers more in this group
See all 7 papers →zinc atom · yield · Vicia faba (faba bean)Results differ
28 papers in the same direction as this paper · 1 in the opposite direction
- positive
- positive
- negative
26 papers more in this group
See all 30 papers →zinc atom · quality: protein · Vicia faba (faba bean)Results agree
8 papers in the same direction as this paper
- positive
- positive
- positive
5 papers more in this group
See all 9 papers →application · quality: protein · Vicia faba (faba bean)Positive and negative results
27 papers in the same direction as this paper · 2 in the opposite direction
- no effect
- no effect
- positive
26 papers more in this group
See all 30 papers →application · yield · Vicia faba (faba bean)Positive and negative results
109 papers in the same direction as this paper · 6 in the opposite direction
- positive
- negative
- no effect
112 papers more in this group
See all 116 papers →application · physiology: osmolytes · Vicia faba (faba bean)Results agree
8 papers in the same direction as this paper
- positive
- positive
- positive
5 papers more in this group
See all 9 papers →application · physiology: pigments · Vicia faba (faba bean)Results agree
22 papers in the same direction as this paper
- positive
- positive
- positive
19 papers more in this group
See all 23 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.