The effect of soil water management on the reflectance characteristics of vine (Vitis vinifera) leaves and ther monitoring by low level airborne video

Abstract

The study site was a vineyard in the Barossa Valley South Australia where two vine varieties Vitis vinifera cv Shiraz and Vitis vinifera cv Cabernet Sauvignon were subjected to three differing water management treatments. Measurements of vine leaf reflectance characteristics, vine vegetative growth and soil moisture status were monitored throughout the growing season. Simultaneously at three dates in combination with ground measurements, the trial site was overflown using an airborne sensor measuring in the visible and near infrared at heights of 700 and 200 metres. The imposed soil water management treatments significantly affected the total soil water content within the soil profile, this difference being accompanied by significant differences in both berry mass and vine vegetative growth for both varieties. However no significant differences in vine leaf reflectance were recorded either between varieties or between soil water management treatments. This may be due to the coarse spectral resolution of the sensors used or the limited range chosen. Airborne video at 700 metres showed considerable promise in detecting vineyard management and soil patterning details and at 200 metres gave sub‐meter spatial resolution allowing for the identification of missing vine positions.