添加生物炭對泥岩土壤侵蝕量之影響

土壤侵蝕受人為干擾及氣候變遷的影響逐漸加劇，引發嚴重的危害。在臺灣由於泥岩極易發生土壤侵蝕，導致下游集水區含砂量激增、環境污染及土地劣化等問題。近年來以生物炭作為土壤改良劑在降低土壤侵蝕量上已有明顯成效，但由於目前相關研究對於在泥岩中添加生物炭以改善泥岩土壤侵蝕方面較少有著墨，因此仍需被研究與探討。本研究將700 oC熱裂解製成之木炭及稻殼炭，以2 %(w/w)為添加量施用於泥岩土壤中，分析受自然降雨侵蝕120天後泥岩理化性質變化，同時收集現地每週土壤侵蝕量，分析添加生物炭處理對泥岩侵蝕量之差異，並於120天侵蝕試驗結束後，觀察試驗區內植被覆蓋情況，分析生物炭改良後對植物在泥岩土壤中生長之影響。由120天之泥岩土壤侵蝕試驗結果顯示，添加2 %木炭後平均可減少39 %的泥岩侵蝕量，而添加2 %稻殼炭後平均可減少44 %的泥岩侵蝕量，顯示添加生物炭可降低泥岩之土壤侵蝕量，其可能為在生物炭改良後，泥岩土壤之有機質增加，且泥岩之總體密度下降，提升土壤孔隙度有助於減少地表逕流水的產生，因此降低泥岩土壤侵蝕量。植被覆蓋方面結果顯示，自侵蝕試驗結束後，植物經過18天的生長，添加生物炭處理之覆蓋率皆可達50 %以上，其中2 %稻殼炭處理更達62 %，為控制組覆蓋率之2倍，由此可知2 %木炭及2 %稻殼炭可促進植物生長，並顯著縮短植生覆蓋的時間。

關鍵字

生物炭；泥岩；土壤侵蝕；植被覆蓋

並列摘要

Soil erosion is gradually affected by human disturbance and climate change and therefore cause serious disaster. In Taiwan, mudstone is extremely susceptible to soil erosion, which leads to problems such as siltation of watershed, environmental pollution, and loss of agricultural production. In recent years, biochar has been used as a soil amendment to reduce soil erosion, but there has less research on the application of biochar to improve soil erosion of mudstone. Therefore it still needs to be studied and discussed. In this study, wood biochar and rice hull biochar are pyrolized with 700 oC, and applied to mudstone soil at application rate of 2 % (w/w) for 120 days, than analysis the effect of biochar on soil erosion. After the 120 day erosion, this study observe the growth and coverage of plants in the test area, and analyze the effect of biochar improvement on plant growth in mudstone soil. The results show that the soil loss of the treatment of 2 % wood biochar addition was significantly lower than the control treatment by 39 %, and the soil loss of the treatment of 2 % rice hull biochar was significantly lower than the control treatment by 44 %. The results of plant coverage show that the treatment of biochar addition could reach more than 50 % coverage at 18 days, and the treatment with 2 % rice hull biochar can increased by 2 fold that of the control. In conclusion, the addition of biochar can effectively reduce soil loss, improve plant growth, and significantly shorten the time of plant cover for mudstone soils.