data. Recent developments in unmanned aerial vehicle (UAV) technology provide cost effective and real time applications for site specific data collection. For the mapping of herbage biomass (BM) on a hill pasture, we tested a UAV system with digital cameras (visible and near-infrared (NIR) camera). The field measurements were conducted on the grazing hill pasture at Hanwoo Improvement Office, Seosan City, Chungcheongnam-do Province, Korea on May 17 and June 27, 2014. Plant samples were obtained from 28 sites. A UAV system was used to obtain aerial photos from a height of approximately 50 m (approximately 30 cm spatial resolution). Normalized digital number (DN) values of Red and NIR channels were extracted from the aerial photos and a normalized differential vegetation index using DN (NDVIdn) was calculated. The results show that the correlation coefficient between BM and NDVIdn was 0.88. For the precision management of hilly grazing pastures, UAV monitoring systems can be a quick and cost effective tool to obtain site-specific herbage BM data.

Ⅰ. INTRODUCTION
Ⅱ. METHODS
Ⅲ. RESULTS AND DISCUSSION
Ⅳ. CONCLUSION
Ⅴ. ACKNOWLEDGEMENT
Ⅵ. REFERENCES

• Hyowon Lee(Department of Agriculture, Korea National Open University) Corresponding author
• Hyo-Jin Lee(Department of Landscape Architecture, Sungkyunkwan University)
• Jong-Sung Jung(National Institute of Animal Science, RDA)
• Han-Jong Ko(Department of Agriculture, Korea National Open University)