Papers by Author: Sun Ok Chung

Abstract: Compaction is becoming a great concern in crop production and the environment. Recently, three has been a need of field management based on site-specific conditions to improve sustainability of agriculture and reduce environmental damage. In the study, soil management or tillage depth was recommended nondestructively based on cone index profiles for typical Korean rice paddy fields. Field variables related to tillage, soil strength, rice growth, and other soil physical properties showed considerable spatial and vertical variations as well as significant (α<0.1) correlations among them. Cone index profiles observed also varied by field sites, and maximum cone index and depth to the maximum cone index showed significant (α<0.1) correlation with tilled depth as well as rice growth and other field variables. When soil management was recommended based on CI measurements, 13.4, 16.8, and 95.3% of the total surveyed areas, and 10.6, 18.9, and 51.6% of the total soil volume were chosen for management depth of 10, 20, 40 cm, respectively, indicating that soils of many field sites would not restrict rice growth. It was concluded that the concept of site-specific soil management based on soil conditions could save labor, time, machine use, and energy.

Abstract: Precision agriculture, also called as site-specific crop (or field) management, is a recent trend in crop production that uses field information collected at different within-field locations to optimize amount, timing, and location of agricultural inputs according to the site-specific requirements. Recent development of soil property sensors has facilitated sensor-based data collection for SSCM in many countries around the world. In this study, commercial soil strength, electrical conductivity, and water content and temperature sensors were applied to a Korean rice (Oriza Sativa L) field and spatial and non-spatial statistical techniques were used to assess soil conditions and the variability, and investigate optimum sampling intensity. Results of the study would be useful for establishment of data collection schemes and better application of soil property sensors to Korean paddy fields for successful precision agriculture.