The study was carried out to develop a mathematical model for evaluating the effect of organic fertilizers in organic rice production systems. A function to simulate the nitrogen mineralization process in the paddy soil has been developed and integrated into ORYZA2000 crop growth model. Inorganic nitrogen in the soil was estimated by single exponential models, given temperature and C:N ratio of organic amendments. Data collected from the two-year field experiment were used to evaluate the performance of the model. The revised version of ORYZA2000 provided reasonable estimates of key variables for nitrogen dynamics and crop growth in the organic rice production systems. Coefficient of determination between the measured value and simulated value were 0.6613, 0.8938, and 0.8092, respectively for soil inorganic nitrogen, total dry matter production, and rice yield. This means that the model could be used to quantify nitrogen supplying capacity of organic fertilizers relative to chemical fertilizer. Nitrogen dynamics and rice growth simulated by the model would be useful information to make decision for organic fertilization in organic rice production systems.

Ⅰ. 서 론
 Ⅱ. 재료 및 방법
  1. 시험토양 및 기상환경
  2. 재료처리
  3. 생육조사 및 분석
  4. 식물체 및 토양분석
  5. ORYZA2000 모형의 수정
 Ⅲ. 결과 및 고찰
  1. 유기자원 처리별 벼 수량
  2. ORYZA2000 모형의 검증
  3. 토양 중 무기태 질소 동태
  4. 벼 생육 변화 추정
 Ⅳ. 결 론
 References

• 신재훈(농촌진흥청 국립농업과학원 기획조정과) | Shin, Jae-Hoon Corresponding author
• 이상민(농촌진흥청 국립농업과학원 유기농업과) | Lee, Sang-Min
• 옥정훈(농촌진흥청 국립농업과학원 유기농업과) | Ok, Jung-Hun
• 남홍식(농촌진흥청 국립농업과학원 유기농업과) | Nam, Hong-Sik
• 조정래(농촌진흥청 국립농업과학원 유기농업과) | Cho, Jung-Lai
• 안난희(농촌진흥청 국립농업과학원 유기농업과) | An, Nan-Hee
• 김광수(서울대학교 농업생명과학대학) | Kim, Kwang-Su