生物炭陶粒作為無土栽培介質之研究

本研究利用採自石門水庫第四和第五沉澱池的水庫底泥以及花生殼粉以不同比例混合，經800 ℃溫度絕氧燒結，製成一種具保水性的新型生物炭陶粒介質，並與傳統工法製成的水庫底泥陶粒及兩種市售無土栽培介質（發泡煉石、火山岩）進行比較，探討生物炭陶粒與傳統陶粒或市售介質在物理、化學與栽培性質上的差異。實驗結果顯示生物炭陶粒具有良好的保水能力，其田間容水量約為20~25 %，高於兩種商用介質的6.1和9.7 %，維持介質從飽和含水至枯萎點的可利用水分時間也高於商用介質的兩倍以上，且隨混合生物炭含量增加而增加。在養分方面，生物炭陶粒保留豐富植物可利用營養元素，如有機碳與無機銨態氮及硝酸態氮，為其他介質所缺乏；生物炭陶粒吸附磷的能力也較其他種介質好，具有能減少磷肥釋放到都市中造成汙染的能力。在為期四個月的萬壽菊(Tagetes erecta)及香蜂草(Melissa officinalis)種植盆栽試驗中，生物炭陶粒盆栽的乾重、苗高以及綠覆蓋面積皆顯著高於商用介質。在限制供水處理中，萬壽菊綠覆蓋面積隨陶粒生物炭含量越高，植物表現也越好。綜合以上結果顯示生物炭陶粒具有作為栽培介質的潛力，然而對其使用的長期穩定性及對植物以及環境的長遠影響仍需更多研究。

關鍵字

水庫底泥；生物炭；綠屋頂；保水力；養分吸附

並列摘要

This study developed a novel growing medium—biochar ceramsite—contented with high water retention and fertile ability. We made the biochar ceramsite by mixing the Shimen Reservoir and peanut shell at different ratios and sintering the mixtures under the anaerobic atmosphere at 800 ℃. The physiochemical and cultivated properties between the biochar ceramsite and two other commercial soilless cultivation media were accessed. The results showed that the biochar ceramsite contented with higher water holding capacity. Its field capacity was about 20 - 25%, higher than two commercial media (6.1% and 9.7%, respectively). The effective water retention time from the saturation to the wilting point is twice higher than commercial media and increased with the biochar content. The biochar ceramsite also contained higher organic carbon and inorganic ammonium and nitrate nitrogen than the commercial media, which were almost absent. The carbon and inorganic nitrogen concentrations increased with the biochar content. The four-month pot experiments showed that the Tagetes erecta and Melissa officinalis growth was better in the biochar ceramsite than other media, with higher dry mass weight, shoot height, and green coverage area. The results suggest that the biochar ceramsite has the potential as a cultivation medium; however, more research is necessary on the long-term stability of the biochar ceramsite and their long-term effects on both plant and environment.