Effects of Application Seasons and Levels of Cattle Slurry Nitrate Contents in Soils of Rye CuItivation

액상발효우분의 시용시기와 시용량이 호밀경작지 토양의 NO₃^- 함량에 미치는 영향

This experiment was conducted to investigate the effects of application seasons and the level of cattle slurry on nitrate contents in soils of rye cultivation under climatic conditions of Korea. The main plots were appliaction seasons(100% application in spring, 100% application in autumn, 50% application in spring and autumnn after dividing cattle slurry into two equal parts) and subplots were the levels of cattle slurry-N application(0, 50, 100 and $200kgN\;ha^{-1}\;year^{-1}$). Cattle slurry was spred evenly over the soil surface in spring (end of March) and autumn(early of November). The experiment was done at Gongiam, Kwangju, Kyung-gi for 3 years, from 1994 to 1996. The results obtained are summarized as follows; 1. Nitrate content in soils was not influenced by application seasons of cattle slurry. 2. Nitrate content in soils increased as the level of cattle slurry application increased, and the average nitrate content became 3.6mg per liter. 3. Nitrate content in the soil depth from 0 to 20cm increased as the level of cattle slurry application increased, and the average nitrate content became 28.9mg per liter. However, nitrate content in the soil depth from 40 to 60cm was the lowest(7.5-8.3mg per liter).

우리나라 기후조건하에서 액상발효 우분의 시용시기(봄, 가을, 봄/가을 분시)와 시용수준(0, 50, 100, $200kgN\;ha^{-1}$)을 달리 했을 때 토양중의 $NO_3^-$ 함량에 대하여 연구한 결과는 다음과 같다. 1. 액상발효 우분의 시용시기는 토양중 $NO_3^-$ 함량에 영향을 미치지 않았다. 2. 액상발효 우분의 시용수준 증가는 $NO_3^-$ 함량을 증가시켰지만 평균 $3.6mg\;l^{-1}$ 에 불과하였다. 3. 토양의 층별 $NO_3^-$ 함량은 0~20cm 깊이에서는 분뇨시용 수준과 비례하여 증가하였고 그 함량도 평균 $28.9mg\;l^{-1}$에 달하였지만, 40~60cm층에서는 시용 수준에 관계없이 $7.5{\sim}8.3mg\;l^{-1}$으로 매우 낮았다.