| 知識類型 | 期刊 |
| 標題 | Biochar Phosphorus Release Is Limited by High pH and Excess Calcium |
| 作者 | Wolfram Buss, Kamonchanard Assavavittayanon, Jessica G. Shepherd, Kate V. Heal, Saran Sohi |
| 名稱(期刊/節目) | Journal of Environmental Quality |
| 期刊期數/節目集數 | Volume 47,Issue 5, Pages 1298-1303 |
| 出版單位 | Wiley |
| 出版年月日 | 2018/9/1 |
| 原文摘要 | Aside from its use for improving soil properties, biochar is increasingly promoted as a direct nutrient provider for sustainable recycling of waste materials. However, incomplete understanding of the interacting factors that determine P release from biochar may limit the efficiency of P recycling from biochar to soil. In particular, the contrasting pH of biochar and soil need to be considered. In this study, soil‐free biochar (rice [Oryza sativa L.] husk, 700°C) extractions were performed under different pH (4.6–9.9) and extractant conditions to test how solution composition affects biochar P release. When solution pH was in the range of 7.6 to 8.6 and excess Ca was present in the solution or in biochar, P release was low—only 1 to 7% of the total P was released compared with ∼20% under most other conditions. Importantly, we demonstrate that biochar total Ca concentration is closely related to P availability (R2 = 0.76) and could be used to predict biochar P release. The results suggest that for maximum P release, low Ca concentrations in biochar and (soil) solution are needed and/or a pH <7.5 at the soil‐biochar interface. This novel understanding will help engineer sustainable biochar fertilizers optimized for P provision. |
| 原文摘要簡述 | 生物炭除了用於改善土壤特性外，亦日趨提倡作為直接養分供應，以達永續的廢棄物質回收利用。然而，對決定磷自生物炭中釋放的相互作用因子了解不完全，可能限制磷自生物炭循環至土壤的效率，尤其是需要考慮到生物炭與土壤pH值的對比。在這項研究中，在不同的pH值(4.6–9.9)和萃取劑條件下進行了無土生物炭(稻[Oryza sativa L.]殼，700°C)提取，以測試溶液成分如何影響生物炭中磷的釋放。當溶液的pH值在7.6至8.6範圍內，且溶液或生物炭中存在過多的鈣時，磷的釋放量很低─僅有總磷的1至7％被釋放，而相較於在大多數其他的條件下，磷的釋放量約為20％。重要的是，我們證明生物炭總鈣濃度與磷的有效性密切相關(R2 = 0.76)，可用於預測生物炭P的釋放。結果顯示，要最大量地釋放磷，需要在生物炭和(土壤)溶液中降低鈣的濃度和/或在土壤-生物炭界面的pH值小於7.5。此種新穎的理解將有助於設計針對磷供應最佳化的永續生物炭肥料。 |
| 關鍵字 | phosphorus release, biochar, solution compositions, pH, calcium |
| 連結 | https://doi.org/10.2134/jeq2018.05.0181 |