为了揭示生物炭对不同质地土壤水分扩散率的影响机理,通过室内水平土柱试验,建立了两种质地土壤含水量与Boltzmann参数、水分扩散率间的定量关系。结果表明:粉砂壤土扩散率在0.15 g g-1处理时最大,在0.05、0.1 g g-1处理时较对照减小;...为了揭示生物炭对不同质地土壤水分扩散率的影响机理,通过室内水平土柱试验,建立了两种质地土壤含水量与Boltzmann参数、水分扩散率间的定量关系。结果表明:粉砂壤土扩散率在0.15 g g-1处理时最大,在0.05、0.1 g g-1处理时较对照减小;砂土扩散率随生物炭含量增大而减小。添加生物炭后,粉砂壤土容重的减小对扩散率无相关性影响,而土壤孔隙度的改变是影响粉砂壤土扩散率的主要因素;随着生物炭含量增大砂土容重减小、孔隙度增大,容重和孔隙度都是影响砂土扩散率的主要因素。试验充分说明生物炭的应用改善了砂土的持水性能,提高砂土的水分有效性;对于粉砂壤土,添加量为0.15 g g-1时能够增加土壤持水性,在0.05、0.1 g g-1时抑制水分的入渗。因此,田间实际应用中生物炭对土壤水分入渗及持水性能的影响取决于生物炭种类、施用量及土壤质地,实验结果为不同质地土壤生物炭应用提供理论依据。展开更多
Horizontal soil column method was used to determine the horizontal diffusion rate of sandy loam, loam and clay loam under the same bulk density. The results showed that the migration rates of different lithological we...Horizontal soil column method was used to determine the horizontal diffusion rate of sandy loam, loam and clay loam under the same bulk density. The results showed that the migration rates of different lithological wet fronts were different. The sandy loam had the fastest migration rate, the loam followed, and the clay loam was the slowest, but the law of change is the same among the three lithologies. The volumetric water content affects the change of Boltzmann parameter λ. When the volumetric water content is between 0.35-0.45 cm^3/cm^3,λ approaches stability. When the volumetric water content is less than 0.35 cm^3/cm^3, the λ value decreases rapidly with the decrease of water content. The water diffusion rate is related to the volumetric water content and particle size. The greater the moisture content is, the greater the diffusion rate will be. The larger the particle size, the larger the diffusion rate. The diffusivity of sandy loam is 10-30 times larger than that of loam and clay loam. The relationship between water content and diffusion rate is in accordance with the exponential function .展开更多
文摘为了揭示生物炭对不同质地土壤水分扩散率的影响机理,通过室内水平土柱试验,建立了两种质地土壤含水量与Boltzmann参数、水分扩散率间的定量关系。结果表明:粉砂壤土扩散率在0.15 g g-1处理时最大,在0.05、0.1 g g-1处理时较对照减小;砂土扩散率随生物炭含量增大而减小。添加生物炭后,粉砂壤土容重的减小对扩散率无相关性影响,而土壤孔隙度的改变是影响粉砂壤土扩散率的主要因素;随着生物炭含量增大砂土容重减小、孔隙度增大,容重和孔隙度都是影响砂土扩散率的主要因素。试验充分说明生物炭的应用改善了砂土的持水性能,提高砂土的水分有效性;对于粉砂壤土,添加量为0.15 g g-1时能够增加土壤持水性,在0.05、0.1 g g-1时抑制水分的入渗。因此,田间实际应用中生物炭对土壤水分入渗及持水性能的影响取决于生物炭种类、施用量及土壤质地,实验结果为不同质地土壤生物炭应用提供理论依据。
基金financially supported by the Fundamental Research Fund of the Chinese Academy of Geological Sciences (YYFM201624)
文摘Horizontal soil column method was used to determine the horizontal diffusion rate of sandy loam, loam and clay loam under the same bulk density. The results showed that the migration rates of different lithological wet fronts were different. The sandy loam had the fastest migration rate, the loam followed, and the clay loam was the slowest, but the law of change is the same among the three lithologies. The volumetric water content affects the change of Boltzmann parameter λ. When the volumetric water content is between 0.35-0.45 cm^3/cm^3,λ approaches stability. When the volumetric water content is less than 0.35 cm^3/cm^3, the λ value decreases rapidly with the decrease of water content. The water diffusion rate is related to the volumetric water content and particle size. The greater the moisture content is, the greater the diffusion rate will be. The larger the particle size, the larger the diffusion rate. The diffusivity of sandy loam is 10-30 times larger than that of loam and clay loam. The relationship between water content and diffusion rate is in accordance with the exponential function .
