College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
Key Laboratory of Water Pollution Control and Environmental Security Technology, Hangzhou, 310058, Zhejiang Province, China.
Environ Sci Pollut Res Int. 2019 Dec;26(36):36367-36379. doi: 10.1007/s11356-019-06762-y. Epub 2019 Nov 12.
Colloidal phosphorus (CP) as an additional route of P mobilization in soil solution has gained much attention. A batch experiment was conducted to investigate the effect of sheep manure-derived biochar (SMB) on CP release from various land uses (paddy, vegetable, tea, and citrus) at a rate of 0% as a control treatment (CK), 1% as a low (L) level, 2% as a middle (M) level, and 4% as a high (H) level of SMB application. The CP and MRP in the solution increased from 30.58 to 88.97% and from 2.45 to 55.54% of total P (TP), respectively. The SMB enhanced CP release in all the soils and all the treatments (except CK and L levels in tea soil; CK, L, and M levels in vegetable soil; and L and M levels in citrus soil). Multiple linear regression revealed a significant correlation between CP and MRP and between colloidal iron, aluminum, calcium, and total organic carbon (Fe, Al, Ca, and TOC) and pH, which may play an important role as CP carriers that could depend on the pH. This study suggests that the application of SMB in the soil at an appropriate rate of 1 and 2% for tea and vegetable soils, respectively, could be beneficial to avoid the risk of CP release in water bodies.
胶体磷（CP）作为土壤溶液中磷释放的另一种途径引起了广泛关注。本批实验旨在研究不同土地利用方式（水稻、蔬菜、茶叶和柑橘）下，羊粪生物炭（SMB）对 CP 释放的影响。实验设置了对照处理（CK）、低（L）水平、中（M）水平和高（H）水平（SMB 投加率分别为 0%、1%、2%和 4%）。结果表明，溶液中的 CP 和 MRP 分别从 30.58%和 2.45%增加到 88.97%和 55.54%的总磷（TP）。SMB 促进了所有土壤和所有处理（茶叶土壤中的 CK 和 L 水平除外；蔬菜土壤中的 CK、L 和 M 水平；柑橘土壤中的 L 和 M 水平除外）中 CP 的释放。多元线性回归分析表明，CP 与 MRP 之间以及胶体铁、铝、钙和总有机碳（Fe、Al、Ca 和 TOC）与 pH 值之间存在显著相关性，它们可能作为 CP 载体发挥重要作用，而 CP 载体可能取决于 pH 值。本研究表明，在茶叶和蔬菜土壤中分别以 1%和 2%的适当比例施用 SMB，可能有助于避免 CP 释放到水体中的风险。
