Amendment of different biochars changed pore characteristics and permeability of Ultisol macroaggregates identified by X-ray computed tomography (CT)
Amendment of different biochars changed pore characteristics and permeability of Ultisol macroaggregates identified by X-ray computed tomography (CT)
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DOI：
10.1016/j.geoderma.2023.116470
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发表时间：
2023-06
期刊：
影响因子：
6.1
通讯作者：
Jingjing Liu;Sheng Lu
中科院分区：
文献类型：
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作者：
Jingjing Liu;Sheng Lu
将不同原料产生的生物炭添加到土壤中会影响土壤团聚，这已被证明对土壤固碳、持水能力和植物生长至关重要。在这项研究中，将350℃下生产的稻秆生物炭（RB）和油菜秆生物炭（CB）以1％的比例添加到Ultisol中。经过三年的培育，土壤中的大团聚体（5-6 毫米）被分离出来，以便使用工业 X 射线计算机断层扫描 (CT) 扫描来量化孔隙结构。相对于 CK 处理，RB 和 CB 处理显着增加了大团聚体的总孔隙度以及连通性与孤立孔隙度的比率（C/I）。生物炭的添加降低了大团聚体中等径孔隙的比例，而增加了长长形、非圆形等不规则孔隙的比例，导致大团聚体孔隙度非均质性较高。双低油菜秆生物炭对孔隙结构的改善作用大于稻秆生物炭，而对孔喉结构的作用则相反。大团聚体的孔隙率、连通性和 SOC 之间存在正相关关系。水流模拟结果表明，RB和CB处理的渗透率分别为25.16μm2和28.62μm2，比CK处理（11.61μm2）分别提高了116.7%和146.5%。结果表明，生物炭改变了大团聚体的孔隙结构，可能增强大团聚体的功能服务，例如 SOC 存储和水力特性。研究结果提供了不同生物炭添加量对大团聚体孔隙结构影响的详细信息，并模拟了大团聚体内土壤水分的运动，这对于理解生物炭影响土壤团聚体的机制及其功能具有重要意义。
The addition of biochars produced by different feedstocks to soil affects soil aggregation, which has been shown to be critical for soil carbon sequestration, water holding capacity and plant growth. In this study, rice stalk biochar (RB) and canola stalk biochar (CB) produced at 350℃ were added to a Ultisol at the 1% rate. After a three-year incubation, the macroaggregates (5–6 mm) in soils were separated for quantification of pore structure using industrial X-ray computed tomography (CT) scanning. The RB and CB treatments significantly increased the total porosity and the ratio of connectivity to isolated porosity(C/I) in macroaggregates relative to CK treatments. The addition of biochars decreased the proportion of equant pores in the macroaggregates, while increased the proportion of irregular pores such as prolate and acircular pores, resulting in the high porosity heterogeneity in macroaggregates. The canola stalk biochar had a larger effect on the improvement of pore structure than rice stalk biochar, while having the opposite effect on pore throat structure. There was a positive correlation between porosity, connectivity and SOC in macroaggregates. Simulation results on water flow showed that the permeability for RB and CB treatments were 25.16 μm2and 28.62 μm2, respectively, which were 116.7% and 146.5% higher than that of CK treatment (11.61 μm2). The results indicated that the biochars altered the pore structure of macroaggregates, potentially enhancing the functional services of macroaggregates such as SOC storage and hydraulic properties. The findings provided the detailed information on the effect of different biochar additions on pore structure in macroaggregates and simulated soil water movement within the macroaggregates, which is important for understanding the mechanism of biochars affecting soil aggregation and its functions.