不同生物炭施用方式對坡地果園土壤性質之影響

本研究使用700℃熱裂解之生物炭(Biochar)及壤土為研究材料，其試驗設計處理有深層環施(deep-banded application in rows,AR)及表土混合施用(topsoil-mixing,TM)並分別與未施用生物炭之試區比較(CK)，而果樹以荔枝及芒果為實驗對象，監測其一年間之土壤溫度、含水量、電導度、土壤沖蝕量，各季節之土壤中有機碳、總氮、有效性氮、有效性磷，以及測量果樹之生長勢以此評估生物炭施用於坡地果園之效益。監測結果顯示施用生物炭後，土壤有機碳及銨態氮含量分別提升3.5-15%及1.7-14%，電導度增加47-78%，而土壤沖蝕量則降低12-20%。但施用生物炭後對其果樹生長無效益，甚至較對照組之生長慢，添加生物炭之果重、果長及果寬皆較對照組減少，分別減少1.6-45%、0.8-11%及2.1-18%，而其糖度及酸度則以表土混合施用最高，分別增加43.4%及38.2%。綜合結果，其生物炭較好之施用方式為深層環施，但對其果樹品質之影響較好為表土混合施用。

關鍵字

生物炭；深層環施；表土混拌；坡地果園

並列摘要

The study used a wood biochar pyrolized with 700℃ as a soil amendment to the soil of slopeland orchards including orchards of litchi and mango. This study aimed to evaluate the effects of different biochar applied ways including “deep-banded application in rows (AR) and topsoil-mixing (TM) on soil properties in the orchards. In our study, soil temperature, water content, electrical conductivity, and soil erosion amounts were monitored for one year. During the experimental period, we analysis organic carbon, total-N, NH4+-N, NO3- -N, Av. P every season in this year. Furthermore, we investigated the growth potential of fruit plants and fruit quality to find a suitable application method of biochar addition on slopeland orchards. The results displayed that the contents of organic carbon and NH4+-N increases by 3.5-15% and 1.7-14%, respectively, compared with the control in two orchards. Additionally, as comparison with the control, electrical conductivity (EC) increased by 47-78% and soil erosion reduced by 12-20% in biochar-treatments. However, biochar application on the orchards seems not to be a well strategy for fruit growing and quality regardless application methods. The weight, length, and width of fruit reduced by 1.6-45%, 0.8-11%, and 2.1-18%, respectively, compared with the control. Regarding the fruit quality, TM seems to be a better way for sweetness and sourness of fruit, which increased 43.4% and 38.2%, respectively, compared with the control. As a whole, AR of the biochar might be the better application way for the soil properties, but TM seems to be better for fruit quality on slopeland orchards.