Effect of Nitrogen Split Application on Growth and Yield in Direct Seeding Rice on Flooded Paddy

담수직파재배시(湛水直播栽培時) 질소분시방법(窒素分施方法)에 따른 벼 생육(生育)과 수량성(收量性)

To investigate the effect of N split application on the increasing ratio of yield and the yield of rice, urea and slow-releasing complex for sideband placement of fertilizer were applied in Jeonbuk series of Honam plain area. Increasing ratio of yield by N split application was higher in puddled drill seeding (PDS) than flooded direct seeding surface (FDSS) under split application of 40-0-30-30% and 70-0-0-30% at basal, 3 leaf, 5 leaf and panicle initiation stage, respectively. It was also higher in LCU application of 70 % of total urea amount than urea application but was not different between two methods of seeding in urea application. Nitrogen ratio transfered to rough grain of rice was higher in FDSS than PDS, errespective of methed of split application, except for the split application of 0, 40, 30 and 30% N fertilizer at basal, 3 leaf, 5 leaf and panicle initiation stage, respectively. Nitrogen amount outflowed by artificial drainage for paddy field drying in a day after application of fertilizer was 1,134g/10a in PDS. $NH_4-N$ incerased higher in PDS than FDSS under split application of urea, while was versa under LCU application.

본(本) 연구(硏究)는 벼 담수직파(湛水直播) 재배시(栽培時) 질소(窒素) 분시방법별(分施方法別) 토양(土壤)의 무기태질소(無機態窒素) 함량(含量), 질소흡수량(窒素吸收量) 및 생육(生育) 및 수양성(收量性)을 검토하고자 호남(湖南) 평야지(平野地) 대표토양(代表土壤)인 전북통(全北統)에서 요소(尿素)와 벼 측조시비용(側條施肥用) 완효성복비(緩效性複肥)(LCU)를 공시비종(供試肥種)으로 하여 포장시험(圃場試驗)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 질소시비효율(窒素施肥效率)은 기비(基肥)-3엽기-5엽기-수비(穗肥)에 40-0-30-30%와 70-0-0-30%로 시용시(施用時) 담수표면직파(湛水表面直播)보다 무논 골뿌림재배(栽培)에서 높았고 LCU전양기비구(全量基肥區)에서는 요소(尿素) 시용구(施用區)보다 효율(效率)은 높았으나 파종방법간(播種方法間)에는 요소시비구(尿素施肥區)와 같았다. 2. 정조(精粗)로의 질소전이률(窒素轉移率)은 추비(追肥)중점(0-40-30-30%)을 제외(除外)하고는 분시방법(分施方法) 공히 무논골뿌림재배(栽培)보다 담수표면직파(湛水表面直播)에서 높았다. 3. 무논골뿌림재배시(栽培時) 논 굳힘을 위해 시비(施肥) 1일후 강제(强制) 배수(排水)에 의해 유출(流出)되는 질소량(窒素量)은 0.1134ton/ha이었다. 4. 전(全) 생육기간(生育期間) 토양중(土壤中) $NH_4-N$ 발현(發現) 양상(樣相)은 요소(尿素)로 시용(施用)할 경우(境遇) 담수표면직파(湛水表面直播)보다 무논골뿌림재배(栽培)에서 높았던 반면 LCU시용시(施用時)는 재배법간(栽培法間)에 요소시용시(尿素施用時)와는 상반된 경향(傾向)을 보였다.