A REVISED SOIL SPECTROPHOTOMETER

摘要

Key points in the revised spectrophotometer design were: use of a RTK-GPS, improved soil penetrator to ensure a uniform soil surface under high speed conditions, and all units are re-arranged for compactness. Test runs proved that the traveling speed could be increased up to about at least 1 m/s, and that the reflectance can also be used for generating soil maps. Derivative operation could eliminate biases on the measured reflectance due to surface disturbance, which enabled to evaluate at least soil moisture and EC.