Relationships between the Spatio-Temporal Variation in Reflectance Data from the Sentinel-2 Satellite and Potato (Solanum Tuberosum L.) Yield and Stem Density
Abstract
:1. Introduction
2. Materials and Methods
2.1. Site Characterisation
2.2. Sampling Design
2.3. Collection and Processing of Satellite Imagery
2.4. Principal Component Analysis
2.5. Rates of Change in Reflectance
2.6. Estimation of Red-Edge Inflection Points
2.7. Yield Data Collection
2.8. Statistical Analysis
3. Results
3.1. Summary of Spectral Reflectance and Intrinsic Indices
3.2. Summary of Temporal Variables
3.2.1. Principal Components of Reflectance at Different Time Points
3.2.2. Temporal Change in the Spectral Signature and Position of the Red-Edge Inflection Point
3.3. Summary Statistics of In-Situ Potato data
3.4. Linear Model for Marketable Yield
3.5. Modelling Stem Density
4. Discussion
5. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Field Name | Location | Variety | Number of Samples | Planting Date | Harvest Date |
---|---|---|---|---|---|
Deaton 6 | 53°12′20.97″N 0°21′55.06″W | Maris Piper | 12 | 10 April 2019 | 05 August 2019 |
HF7 | 53°12′40.71″N 0°24′49.76″W | Maris Piper | 23 | 12 April 2020 | 18 August 2020 |
Buttery Hill | 52°46′22.05″N 2°25′40.46″W | Amora | 30 | 20 March 2020 | 24 July 2020 |
Horse Foxhole | 52°46′26.94″N 2°25′49.38″W | Amora | 23 | 27 March 2019 | 11 July 2019 |
Crabtree Leasow | 52°46′15.73″N 2°25′35.51″W | Pentland Dell | 6 | 16 April 2020 | 21 August 2020 |
Index Name | Main Reported Use | Formula | Reference |
---|---|---|---|
Normalized Difference Vegetation Index (NDVI) | Classification of vegetation against non-vegetation background | [4] | |
Specific Leaf Area Vegetation Index (SLAVI) | Approximating leaf area index | [53] | |
Chlorophyll Index Green (CIG) | Approximating vegetation chlorophyll variations | [54] | |
Normalized Difference Moisture Index (NDMI) | Approximating vegetation moisture variation | [55] |
Site * | NDVI 1 | SLAVI 2 | CIG 3 | NDMI 4 | REIP 5 (nm) | REIPr 6 | NDVIinit 7 |
---|---|---|---|---|---|---|---|
D6 | 0.93 (0.01) | 5.88 (0.12) | 4.17 (0.48) | 0.53 (0.01) | 723.66 (0.51) | 170 (9) | 0.62 (0.09) |
HF7 | 0.94 (0.03) | 5.56 (0.91) | 5.21 (1.00) | 0.58 (0.04) | 711.68 (21.23) | 153 (18) | 0.53 (0.03) |
BH | 0.94 (0.03) | 5.18 (0.71) | 3.32 (0.83) | 0.51 (0.03) | 723.39 (0.42) | 268 (28) | 0.14 (0.14) |
CT | 0.87 (0.02) | 3.85 (0.31) | 4.10 (1.63) | 0.44 (0.02) | 719.01 (2.20) | 305 (19) | 0.51 (0.11) |
HFx | 0.81 (0.03) | 3.38 (0.35) | 5.51 (0.61) | 0.44 (0.03) | 722.56 (0.49) | 457 (7) | 0.35 (0.06) |
Location | Principal Component 1 | Principal Component 2 | Principal Component 3 |
---|---|---|---|
Deaton 6 | 81.44 (0.24) | 18.49 (0.23) | 0.06 (0.01) |
HF7 | 82.73 (10.34) | 16.87 (10.51) | 0.32 (0.41) |
Buttery Hill | 88.96 (5.67) | 10.71 (5.64) | 0.26 (0.06) |
Crabtree Leasow | 90.54 (6.58) | 9.34 (6.55) | 0.08 (0.03) |
Horse Foxhole | 87.57 (5.13) | 12.24 (1.07) | 0.14 (0.06) |
Yield Component | Deaton 6 | HF7 | Buttery Hill | Crabtree Leasow | Horse Foxhole |
---|---|---|---|---|---|
Marketable yield (kg/m2) | 4.17 (0.48) | 5.21 (1.00) | 3.32 (0.83) | 4.10 (1.63) | 5.49 (0.61) |
Number of Plants/m2 | 2.50 (0.29) | 2.51 (0.60) | 2.78 (0.70) | 2.67 (0.61) | 5.19 (1.58) |
Number of Stems/m2 | 9.77 (1.67) | 12.37 (4.17) | 13.52 (3.83) | 12.22 (2.83) | 17.03 (2.70) |
Explanatory Variables | Estimate 1 |
---|---|
Intercept | 4.47 ± 0.18 |
NDVIinit 2 | 0.55 ± 0.19 |
Stem Density | 0.48 ± 0.18 |
λ559 | −0.53 ± 0.18 |
λ703 | 0.22 ± 0.19 |
Model Properties | |
nRMSEfixef 3 | 0.16 |
delta AICc 4 | 18.56 |
R2 | 0.65 |
D.F. 5 | 87.99 |
CC1 6 | 0.21 |
Explanatory Variables | Estimate 1 |
---|---|
Intercept | 13.5 ± 1.42 |
REIPDAP 2 | 1.18 ± 0.79 |
REIPr 3 | 3.43 ± 1.9 |
SLAVIpeak 4 | 1.66 ± 1.59 |
NDVIinit 5 | 1.19 ± 1.01 |
Model Properties | |
nRMSEfixef 6 | 0.24 |
delta AICc 7 | 18.92 |
R2 | 0.51 |
D.F. 8 | 74.17 |
ICC1 9 | 0.28 |
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Mhango, J.K.; Harris, W.E.; Monaghan, J.M. Relationships between the Spatio-Temporal Variation in Reflectance Data from the Sentinel-2 Satellite and Potato (Solanum Tuberosum L.) Yield and Stem Density. Remote Sens. 2021, 13, 4371. https://doi.org/10.3390/rs13214371
Mhango JK, Harris WE, Monaghan JM. Relationships between the Spatio-Temporal Variation in Reflectance Data from the Sentinel-2 Satellite and Potato (Solanum Tuberosum L.) Yield and Stem Density. Remote Sensing. 2021; 13(21):4371. https://doi.org/10.3390/rs13214371
Chicago/Turabian StyleMhango, Joseph K., W. Edwin Harris, and James M. Monaghan. 2021. "Relationships between the Spatio-Temporal Variation in Reflectance Data from the Sentinel-2 Satellite and Potato (Solanum Tuberosum L.) Yield and Stem Density" Remote Sensing 13, no. 21: 4371. https://doi.org/10.3390/rs13214371