Fig. 1. No.11 and No.12-2 of No.17 operation station in No.4 management area of Zhaoguang farm

Fig. 2. Spectral information collection platform for crop canopy

Fig. 3. Field of spectral information collection of crop canopy

Fig. 4. Flow chart of model-based fuzzy c-means algorithm

Fig. 5. SSE change curves of NDVI data under different partition numbers
(a): Soybean; (b): Maize

Fig. 6. Silhouette coefficients of different NDVI data volumes
(a): Soybean; (b): Maize

Fig. 7. Adjusted Rand index of different NDVI data volumes
(a): Soybean; (b): Maize

Fig. 8. Time costs of two algorithms under different NDVI data volumes
(a): Soybean; (b): Maize

Fig. 9. Fertilization management zoning calculated by two algorithms for 4 000 soybean NDVI
(a): FCM algorithm; (b): MFCM algorithm

Fig. 10. Fertilization management zoning calculated by two algorithms for 8 000 soybean NDVI
(a): FCM algorithm; (b): MFCM algorithm

Fig. 11. Fertilization management zoning calculated by two algorithms for 4 000 soybean NDVI
(a): FCM algorithm; (b): MFCM algorithm

Fig. 12. Fertilization management zoning calculated by two algorithms for 8 000 soybean NDVI
(a): FCM algorithm; (b): MFCM algorithm