Abstract
The system fertilization approach emerged to improve nutrient use efficiency in croplands. This new fertilization concept aims at taking advantage of nutrient cycling within an agroecosystem to obtain maximum production from each nutrient unit. To monitor this effect, methodologies such as the Normalized Difference Vegetation Index (NDVI) are promising to evaluate plant biomass and nutrient content. We evaluated the use of NDVI as a predictor of shoot biomass, P and K uptake, and yield in soybean. Treatments consisted of two production systems [integrated crop-livestock system (ICLS) and cropping system (CS)] and two periods of phosphorus (P) and potassium (K) fertilization (crop fertilization—P and K applied at soybean sowing—and system fertilization—P and K applied in the pasture establishment). NDVI was evaluated weekly from the growth stage V2 up to growth stage R8, using the Greenseeker ® canopy sensor. At the growth stages V4, V6, R2, and R4, plants were sampled after NDVI evaluation for chemical analysis. Soybean yield and K uptake were similar between production systems and fertilization strategies ( P > 0.05). Soybean shoot biomass and P uptake were, respectively, 25.3% and 29.7% higher in ICLS compared to CS ( P < 0.05). For NDVI, an interaction between the production system and days after sowing ( P < 0.05) was observed. NDVI increased to 0.95 at 96 days after sowing in CS and to 0.92 at 92 days after sowing in ICLS. A significant relationship between NDVI and shoot biomass, and P and K uptake was observed ( P < 0.05). Our results show that the vegetation index NDVI can be used for estimating shoot biomass and P and K uptake in the early growth stages of soybean crops, providing farmers with a new tool for evaluating the spatial variability of soybean growth and nutrition.
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Claims 11
Claim · model-written summary
Soybean yield was similar across production systems and fertilization strategies.
- Taxon
- Soybean
Glycine maxe0 - Treatment
- production systems and fertilization strategiese0
- Outcome
- yielde0
- Direction
- similare0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean yield and K uptake were similar between production systems and fertilization strategies ( P > 0.05)”
Claim · model-written summary
Soybean potassium uptake was similar across production systems and fertilization strategies.
- Taxon
- SoybeanGlycine maxe0
- Treatment
- production systems and fertilization strategiese0
- Outcome
- K uptakee0
- Direction
- similare0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean yield and K uptake were similar between production systems and fertilization strategies ( P > 0.05)”
Claim · model-written summary
Soybean shoot biomass was 25.3% higher in ICLS than CS.
- Taxon
- SoybeanGlycine maxe0
- Treatment
- ICLSe0
- Outcome
- shoot biomasse0
- Direction
- highere0
- Value
- 25.3%e0
- Comparator
- CSe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean shoot biomass and P uptake were, respectively, 25.3% and 29.7% higher in ICLS compared to CS ( P < 0.05)”
Claim · model-written summary
Soybean phosphorus uptake was 29.7% higher in ICLS than CS.
- Taxon
- SoybeanGlycine maxe0
- Treatment
- ICLSe0
- Outcome
- P uptakee0
- Direction
- highere0
- Value
- 29.7%e0
- Comparator
- CSe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean shoot biomass and P uptake were, respectively, 25.3% and 29.7% higher in ICLS compared to CS ( P < 0.05)”
Claim · model-written summary
NDVI showed an interaction between production system and days after sowing.
- Taxon
- soybeanGlycine maxt0
- Treatment
- production systeme0
- Outcome
- NDVIe0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For NDVI, an interaction between the production system and days after sowing ( P < 0.05) was observed”
t0“soybean biomass”
Claim · model-written summary
In CS, NDVI increased to 0.95 at 96 days after sowing.
- Taxon
- soybeanGlycine maxt0
- Outcome
- NDVIe0
- Direction
- increasede0
- Value
- 0.95e0
- Qualifier
- 96 days after sowinge0
- Setting
- CSe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“NDVI increased to 0.95 at 96 days after sowing in CS”
t0“soybean biomass”
Claim · model-written summary
In ICLS, NDVI increased to 0.92 at 92 days after sowing.
- Taxon
- soybeanGlycine maxt0
- Outcome
- NDVIe0
- Direction
- increaseinferrede0
- Value
- 0.92e0
- Qualifier
- 92 days after sowinge0
- Setting
- ICLSe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“NDVI increased to 0.95 at 96 days after sowing in CS and to 0.92 at 92 days after sowing in ICLS”
t0“soybean biomass”
Claim · model-written summary
NDVI was significantly related to soybean shoot biomass.
- Taxon
- soybeanGlycine maxt0
- Treatment
- NDVIe0
- Outcome
- shoot biomasse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A significant relationship between NDVI and shoot biomass, and P and K uptake was observed ( P < 0.05)”
t0“soybean biomass”
Claim · model-written summary
NDVI was significantly related to soybean phosphorus uptake.
- Taxon
- soybeanGlycine maxt0
- Treatment
- NDVIe0
- Outcome
- P and K uptakee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A significant relationship between NDVI and shoot biomass, and P and K uptake was observed ( P < 0.05)”
t0“soybean biomass”
Claim · model-written summary
NDVI was significantly related to soybean potassium uptake.
- Taxon
- soybeanGlycine maxt0
- Treatment
- NDVIe0
- Outcome
- K uptakee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A significant relationship between NDVI and shoot biomass, and P and K uptake was observed ( P < 0.05)”
t0“soybean biomass”
Claim · model-written summary
NDVI can estimate shoot biomass and P and K uptake in early soybean growth stages.
- Taxon
- soybeanGlycine maxe0
- Outcome
- estimating shoot biomass and P and K uptakee0
- Qualifier
- early growth stagese0
Not reportedComparatorValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the vegetation index NDVI can be used for estimating shoot biomass and P and K uptake in the early growth stages of soybean crops”
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