빗물활용 옥상녹화 식재지반에 따른 한라구절초의 생육 변화

Abstract

본 연구는 빗물 활용 옥상녹화에서 식재기반 차이에 따른 한라구절초의 생육 변화를 살펴보고, 적합한 토심과 토양배합비를 제시함으로써 옥상조경 식물소재로 활용성을 높이고자 한다. 토심(15cm, 25cm)과 토양배합비(SL, <TEX>$P_7P_1L_2$</TEX>, <TEX>$P_6P_2L_2$</TEX>, <TEX>$P_5P_3L_2$</TEX>, <TEX>$P_4P_4L_2$</TEX>)를 각각 다르게 실험구를 조성하였으며, 내건성과 관상가치가 뛰어난 한라구절초를 식재한 후 초장, 녹피율, 엽록소 함량, 생체중과 건조중, T/R율 등을 측정하였다. 토심 15cm처리구에서 토양배합비에 따른 한라구절초의 초장의 경우 통계적 유의성은 발견되지 않으나, 전반적으로 PPL배합토인 <TEX>$P_7P_1L_2$</TEX>, <TEX>$P_6P_2L_2$</TEX>, <TEX>$P_5P_3L_2$</TEX>, <TEX>$P_4P_4L_2$</TEX>가 사양토인 SL보다 높았다. 토심 25cm처리구의 경우, SL < <TEX>$P_7P_1L_2$</TEX>, <TEX>$P_6P_2L_2$</TEX>, <TEX>$P_5P_3L_2$</TEX> < <TEX>$P_4P_4L_2$</TEX> 순으로 초장이 길었다. 녹피율의 경우 토심 15cm처리구에서는 초장과 같이 토양배합비에 의한 차이는 뚜렷하지 않았으나, 수치적으로는 SL처리구에서 가장 낮았다. 토심 25cm처리구의 전체적으로 86~89%의 높은 피복률을 나타냈다. 엽록소 함량은 토심 15cm처리구에서 SL이 가장 높게, <TEX>$P_5P_3L_2$</TEX>이 가장 낮았으며, 토심 25cm처리구에서는 <TEX>$P_4P_4L_2$</TEX>과 SL에서 가장 높은 값을, <TEX>$P_7P_1L_2$</TEX>에서 가장 낮은 값을 보였다. 생체중과 건물중의 경우 배합비보다는 토심에 따른 차이가 더 뚜렷하여 토심 25cm처리구가 15cm처리구보다 높았다. 따라서 빗물활용 옥상녹화 식재지반에 있어 한라구절초의 생육은 토심 25cm가 토심 15cm보다, PPL배합토, 특히, 피트모스함량이 높은 <TEX>$P_4P_4L_2$</TEX>이 사양토보다 더 적합한 생육환경을 제공해 주는 것으로 분석되었다. This study aims to suggest a suitable soil thickness and soil mixture ratio of a green roof system by verifying the growth of Chrysanthemum zawadskii var. coreanum as affected by different green roof systems using rainwater. The experimental planting grounds were made with different soil thicknesses(15cm, 25cm) and soil mixing ratios (SL, <TEX>$P_7P_1L_2$</TEX>, <TEX>$P_6P_2L_2$</TEX>, <TEX>$P_5P_3L_2$</TEX>, <TEX>$P_4P_4L_2$</TEX>) and with excellent drought tolerance. Ornamental value Chrysanthemum zawadskii var. coreanum was planted. The change in plant height, green coverage ratio, chlorophyll content, fresh weight, dry weight, and dry T/R ratio of Chrysanthemum zawadskii var. coreanum were investigated from April to October 2009. For 15cm soil thickness, the plant height of Chrysanthemum zawadskii var. coreanum was not significantly different as affected by the soil mixing ratio. However, it was found to be higher in the amended soil mixture, <TEX>$P_7P_1L_2$</TEX>, <TEX>$P_6P_2L_2$</TEX>, <TEX>$P_5P_3L_2$</TEX> and <TEX>$P_4P_4L_2$</TEX> than in the sandy loam soil, as it was SL overall. For 25cm soil the plant height differences were in order to SL < <TEX>$P_7P_1L_2$</TEX>, <TEX>$P_6P_2L_2$</TEX>, <TEX>$P_5P_3L_2$</TEX> < <TEX>$P_4P_4L_2$</TEX>. The green coverage ratio was observed not to be different by soil mixing ratio with soil thickness of 15cm, but, the lowest green coverage ratio in the SL. In the 25cm soil thickness, the green coverage ratio was 86-89% with a good coverage rate overall. The change in chlorophyll contents with 15cm soil thickness was found to be the highest in the SL treatment and the lowest in the <TEX>$P_5P_3L_2$</TEX> treatment. For 25cm thickness, the highest value was in the <TEX>$P_4P_4L_2$</TEX> and SL, and the lowest in the<TEX>$P_7P_1L_2$</TEX>. Fresh weight and dry weight were larger in soil with 25cm thickness. Therefore, the growth of Chrysanthemum zawadskii var. coreanum as affected by a different green roof system for using rainwater was higher in soil with 25cm thickness than 15cm, and in PPL amended soil than in sandy loam.