Effect of Banded Subsoil Fertilization on the Yields and N Utilization of Radish (Raphanus sativus L.) in Plastic Film Mulching Cultivation

To establish law-put fertilization technique and increase of fertilization efficiency during cultivation of plastic film mulching for plastic the improvement of soil properties, nutrition efficiency and yield by banded subsoil fertilization (BSF) using band spoty applicator was conducted at radish (Raphanus sativus L.) field in Honan Agricultural Research Institute from 1997 to 1998 for 2 years. These results were as follows. T-N, available $P_2O_5$ exchangeable Ca and K contents of soil were increased those of before experiment especially in BSF treatment. Also, the content of soil $NO_3-N$ was higher in BSF as fertilization amount is increasing than in CF (conventional fertilization). Uptake amounts of nitrogen fertilized were high in BSF during overall the growth period of plant and N utilization was high by $21.9{\sim}30.4%$ in BSF compared to in CF. The rate of fertilizer loss by rainfall was largely reduced, because all fertilizer applied was putted around the root zone. The total yields of fresh radish BSF treatments were more increased $13{\sim}37%$ than that of CF treatment.

무 재배시 질소이용률 및 수량에 미치는 토중시비 효과

비닐피복작물 재배시 시비효율 증대 및 생력시비기술 확립을 위하여 토중시비기를 개발하였고 1997년부터 1998년까지 2년 동안 이를 이용하여 무를 재배한 후 토양개량, 양분이용률 및 수량성에 미치는 영향을 평가하였으며 그 결과는 다음과 같다. 시험 전에 비하여 총질소, 유효인산, 치환성 칼륨 및 칼슘 함량이 많아졌으며 토중시비에서 증가율이 컸으며 토양 중 $NO_3-N$ 함량은 관행시비에 비해 토중시비에서 시비수준이 높을수록 많았다. 식물체 중 시비질소 흡수량은 토중시비에서 전 생육기간 동안 많았고 질소이용률은 관행시비 32.0% 에 비하여 토중시비에서 $21.9{\sim}30.4%$ 높았으며 토중시비로 작물근접에 시비가 가능하여 강우에 의한 시비질소의 손실률이 크게 감소되었다. 무 뿌리 개당 500 g 이상의 상품성 비율이 관행시비 53.2%에 비하여 토중시비 70%, 100%에서 $58.4{\sim}61.2%$ 높았으며 총수량은 관행시비 61.46 Mg $ha^{-1}$ 대비 $13{\sim}37%$ 증수되었다.