다중 센싱 기반 중간물떼기 기간에 따른 벼 생육 특성 변화

Changes in Rice Growth Characteristics during Intermittent Drainage Period using Multiple Sensing Technology

중간물떼기 기간연장에 따른 벼 생육반응 변화를 분석한결과는 다음과 같다. 1. 관행 2주간 중간물떼기 대비 중간물떼기 기간이 3주로연장되었을 경우 수량 및 수량구성요소는 유의한 차이가 없다. 2. 중간물떼기 기간이 4주로 연장되었을 경우 임실률과 영화수, 수량이 급격하게 감소하였다. 3. 중간물떼기가 4주 이상 지속될 경우 NDVI, PRI, CWSI 값이 유의하게 변화하였다. 4. 중간물떼기 기간 연장에 따른 식생지수별 생육지표와의관계를 분석한 결과 NDVI 대비 CWSI가 약 4일 정도더 빠르게 한발 스트레스를 감지하였으며 가역적 스트레스 또한 용이하게 확인할 수 있었다.

The risk of global warming is increasing due to rapid climate change and increased greenhouse gas (GHG) emissions. Among the greenhouse gases, methane has a strong warming effect; in particular, 51.2% of the agricultural sector’s methane emissions are from flooded rice fields. According to the current standard rice cultivation method, rice is grown during the maximum tillering stage with an intermittent drainage period of approximately 2 weeks. During the flooding period, methaneproducing bacteria are active, but the activity of methane-producing bacteria and the amount of methane gas produced are reduced when the soil becomes oxidized through watering. Accordingly, this study used multiple-sensing technology to analyze the growth response according to the intermittent drainage period and to identify the extended intermittent drainage period with less impact on rice production. The equipment used for growth observations included NDVI, PRI, and IR sensors. The results confirmed that growth indices related to stress, such as NDVI and PRI, were not significantly different from those of the control when treated within 3 weeks of drainage, but drastically decreased when the drainage period was extended beyond 4 weeks. These results appear to result from the fact that soil water content (volumetric water content) also dropped to below 20% 4 weeks after irrigation, creating actual drought stress conditions. The 22nd day after treatment, when the soil moisture content reached 20%, was considered the point in time when drought stress conditions were formed. The point at which the SPAD value decreased to 0.6% of normal was estimated to be 23.5 days after treatment by using the regression equation between NDVI and SPAD.