Impact of Wood Biochar Addition on Nutrient Leaching and Fertility in a Rural Ultisols of Taiwan

臺灣農地極育土中添加木質生物炭對養分淋洗與肥力的影響

蔡呈奇(Chen-Chi Tsai) ； 張瑀芳(Yu-Fang Chang) ； 黃國雄(Gwo-Shyong Hwang) ； 許正一(Zeng-Yei Hseu)

《臺灣農業化學與食品科學》 51卷2期 (2013/04) Pp. 80-93

https://doi.org/10.6578/TJACFS.2013.010

摘要

在高度風化的土壤中，生物炭的添加可以提高土壤的品質與降低養分的淋溶損失，但是生物炭的添加對於退化土壤的影響，較少被研究與發表。本研究假設添加生物炭有助於改善和恢復退化土壤的養分狀況，因此本文的研究目的在於量化添加木質生物炭對於退化土壤的土壤肥力特性與水份淋洗液化學組成份的影響。包含0、2.0、4.0與8.0%（wt/wt）生物炭的土壤管柱經填妥後，進行孵育試驗共孵育80天，並且每十天以定量蒸餾水淋洗土壤管柱，在第0天與第80天分別採集與分析土壤樣本中的肥力。研究結果指出，添加木質生物炭到土壤中提高土壤的pH值、土壤總碳量、陽離子交換容量與孟立克-3可抽出性錳的含量，但是降低可交換性鈉、鈣與鎂、孟立克-3可抽出性鈣、鎂、銅與鉛的含量。另外，添加木質生物炭並不會顯著影響土壤中的總氮、可交換性鉀、孟立克-3可抽出性磷、鉀、鐵與其它微量元素的含量。淋洗液的研究結果指出，淋洗液的pH值與鉀的濃度隨著木質生物炭添加量的增加而提高，但是電導度、碳、氮、鈣、鎂、微量元素、硝酸與磷酸離子濃度卻是降低的。本研究之試驗結果表明，添加木質生物炭到退化土壤中能夠大幅度的減少養分的淋溶，這表示添加木質生物炭是一種有效減少養分淋失的方法。整體而言，應用木質生物炭到臺灣的土壤中可以產生一個雙贏的局面，包括碳的吸存以及改善退化黏質土壤肥力的潛勢。

關鍵字

木質生物炭 ； 極育土 ； 養分淋溶 ； 土壤肥力

並列摘要

Biochar increases the quality of soil and reduces the leaching of nutrients in highly weathered soils. Little, however, is known about the effects of biochar on degraded soils. Therefore, this study hypothesized that adding biochar helps ameliorate and recover the nutrient status of degraded soils. Our purposes are to quantify the effect of adding wood biochar (WB) on the soil fertility characteristics and water leachate chemistry of a degraded soil. Repacked soil columns that contain 0, 2.0, 4.0, and 8.0% (wt/wt) WB were incubated and leached every ten days for 80 days. On days 0 and 80, soil samples were collected and analyzed for fertility. The results demonstrated that adding WB to the soil increased soil pH, soil total carbon, cation exchange capacity and the amount of Mehlich 3 extractable Mn, but reduced the amounts of exchangeable Na, Ca, Mg, Mehlich 3 extractable Ca, Mg, Cu, and Pb. Adding WB did not significantly influence the amounts of total N, exchangeable K, Mehlich 3 extractable P, K, Fe, and other microelements in the soil. The results of leachates showed that the pH and K concentration increased with the increased amount of added WB, but the conductivity and the concentrations of C, N, Ca, Mg, microelements, NO3^-, and PO4^(3-) decreased. These results reveal that adding WB to a degraded soil substantially reduced nutrient leaching, suggesting that adding WB is an effective means of reducing nutrient leaching. In conclusion, applying WB to soils in Taiwan may yield a win-win situation, involving C sequestration and the potential to improve fertility of degraded clayey soil.

並列關鍵字

Wood biochar (WB) ； Ultisols ； Nutrient leaching ； Soil fertility