For appropriate nutrient management and enhanced plant growth, soil sensors which reflect soil nutrient levels are required. Because there is no available sensor for nutrient monitoring, electrical conductivity (EC) sensor can be used to evaluate soil nutrient levels. Soil nutrient management using EC sensors would be possible by understanding the relationship between sensor EC values and soil temperature, moisture, and nutrient content. However, the relationship between soil sensor EC values and plant available nutrients was not investigated. Therefore, the objectives of the study were to evaluate effect of different amount of urea on soil EC monitored by sensors during pepper and broccoli cultivation and to predict the plant available nutrient contents in soil. During the cultivation period, soil was collected periodically for analyzing pH and EC, and the available nutrient contents. The sensor EC value increased as the moisture content increased, and low fertilizer treated soil showed the lowest EC value. Principal component analysis was performed to determine the relationship between sensor EC and available nutrients in soil. Sensor EC showed a strong positive correlation with nitrate nitrogen and available Ca. In addition, sum of available nutrients such as Ca, Mg, K, P, S and N was positively related to the sensor EC values. Therefore, EC sensors in open field can be used to predict plant available nutrient levels for proper management of the soil.

서 론
재료 및 방법
    1. 고추와 브로콜리 생육 및 비료 처리
    2. 센서를 이용한 토양 EC 모니터링
    3. 고추와 브로콜리 토양 분석
    4. 데이터 통계처리
결과 및 고찰
    1. 고추와 브로콜리 생육 기간 동안 토양 EC 센서 모니터링
    2. 비료 처리에 따른 토양 양분 함량 평가
    3. 센서 EC와 유효태 토양 양분 함량의 상관관계
적 요
사 사

• 신수경(충북대학교 농화학과 대학원생) | Su Kyeong Sin (Graduate Student, Department of Agricultural Chemistry, Chungbuk National University, Cheongju 28644, Korea)
• 김정연(충북대학교 농화학과 대학원생) | Jeong Yeon Kim (Graduate Student, Department of Agricultural Chemistry, Chungbuk National University, Cheongju 28644, Korea)
• 박진희(충북대학교 환경생명화학과 교수) | Jin Hee Park (Professor, Department of Environmental and Biological Chemistry, Chungbuk National University, Cheongju 28644, Korea) Corresponding author