TY - JOUR
T1 - The comparison of Canopeo and samplepoint for measurement of green canopy cover for forage crops in India
AU - Govindasamy, Prabhu
AU - Mahawer, Sonu Kumar
AU - Sarangi, Debalin
AU - Halli, Hanamant M.
AU - Das, T. K.
AU - Raj, Rishi
AU - Pooniya, Vijay
AU - Muralikrishnan, L.
AU - Kumar, Sunil
AU - Chandra, Amaresh
N1 - Funding Information:
Authors would like to thank researchers of the Indian Grassland and Fodder Research Institute for their help and support in this research. Also, the authors are thankful to Dr. Anup Kumar and Mrs. Sudha Gunasekaran for their help in this research.
Publisher Copyright:
© 2022 The Author(s)
PY - 2022/1
Y1 - 2022/1
N2 - Canopy covers can be measured using destructive (visual) and non-destructive methods (spectral indices, photogrammetry, visual assessment, and quantum sensor). The precision of crop cover estimation, however, is dependent on the selection of appropriate methods. Studies were conducted at the Indian Grassland and Fodder Research Institute, Jhansi to compare the forage crops canopy cover estimated using photogrammetry software (Canopeo and SamplePoint) and visual assessments. Assessments were performed in three summer crops (corn, cowpea, and sorghum), two winter crops (Egyptian clover, and oats), and bare ground condition. For each plot, three nadir images (directly above the canopy) were captured using digital cameras from a height of 1.5 m above the soil surface between 10 AM to 2 PM on bright sunny days. The results indicated that the relationships between visual assessment and Canopeo (regression coefficient, (R2 = 0.96), visual assessment and SamplePoint (0.96), and Canopeo and SamplePoint (0.98) were linear when data were pooled across all the crops. SamplePoint and Canopeo is further, appropriate for cowpea (Pearson coefficient (R = 0.99 and 0.94), oats (0.92 and 0.97), and sorghum (0.46 and 0.51), respectively. SamplePoint and Canopeo are not suitable for berseem (-0.15) and corn (-0.61), respectively, due to dead residues after the first harvest in berseem and taller corn might have influenced the image quality. Therefore, the stage of the crop, the height of the crop, and dead residues around the plants can greatly influence the estimation of crop cover. In conclusion, the results indicated that this photogrammetry software can be used for non-destructive crop canopy measurement with the above-mentioned precautions in the forage crops tested. • Forage canopy cover is estimated generally by visual scoring, and the outcome varies widely from person to person. • Photogrammetry methods (Canopeo and SamplePoint) were positiviely correlated with visual scoring for cowpea, oats, and sorghum. • However, Canopeo and SamplePoint may not suitable for taller crops like corn and ratoon crops like berseem.
AB - Canopy covers can be measured using destructive (visual) and non-destructive methods (spectral indices, photogrammetry, visual assessment, and quantum sensor). The precision of crop cover estimation, however, is dependent on the selection of appropriate methods. Studies were conducted at the Indian Grassland and Fodder Research Institute, Jhansi to compare the forage crops canopy cover estimated using photogrammetry software (Canopeo and SamplePoint) and visual assessments. Assessments were performed in three summer crops (corn, cowpea, and sorghum), two winter crops (Egyptian clover, and oats), and bare ground condition. For each plot, three nadir images (directly above the canopy) were captured using digital cameras from a height of 1.5 m above the soil surface between 10 AM to 2 PM on bright sunny days. The results indicated that the relationships between visual assessment and Canopeo (regression coefficient, (R2 = 0.96), visual assessment and SamplePoint (0.96), and Canopeo and SamplePoint (0.98) were linear when data were pooled across all the crops. SamplePoint and Canopeo is further, appropriate for cowpea (Pearson coefficient (R = 0.99 and 0.94), oats (0.92 and 0.97), and sorghum (0.46 and 0.51), respectively. SamplePoint and Canopeo are not suitable for berseem (-0.15) and corn (-0.61), respectively, due to dead residues after the first harvest in berseem and taller corn might have influenced the image quality. Therefore, the stage of the crop, the height of the crop, and dead residues around the plants can greatly influence the estimation of crop cover. In conclusion, the results indicated that this photogrammetry software can be used for non-destructive crop canopy measurement with the above-mentioned precautions in the forage crops tested. • Forage canopy cover is estimated generally by visual scoring, and the outcome varies widely from person to person. • Photogrammetry methods (Canopeo and SamplePoint) were positiviely correlated with visual scoring for cowpea, oats, and sorghum. • However, Canopeo and SamplePoint may not suitable for taller crops like corn and ratoon crops like berseem.
KW - Canopeo and SamplePoint
KW - Crop cover
KW - Nadir image
KW - Non-destructive method
KW - Photogrammetry
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U2 - 10.1016/j.mex.2022.101916
DO - 10.1016/j.mex.2022.101916
M3 - Article
C2 - 36438857
AN - SCOPUS:85144312321
SN - 2215-0161
VL - 9
JO - MethodsX
JF - MethodsX
M1 - 101916
ER -