生物炭对黑垆土土壤水分运移特征参数影响

Effects of biochar on soil water transport characteristics of Heilu soil

为了了解生物炭施加对宁南山区黑垆土土壤水分运移特征参数影响,以宁南山区典型土壤黑垆土为研究对象,按0%,1%,2%和3%的比例将土壤改良剂生物炭施加到垂直和水平土柱中,探讨不同施加比例下入渗速率、饱和体积含水量、饱和导水率、饱和扩散率等土壤水分运移特征参数的变化.研究结果表明:生物炭施加比例1%,2%和3%的土壤体积含水量较0%增加了2.98%,6.45%和7.94%,生物炭施加减缓了土壤入渗速率,提高了土壤持水性能;Philip模型比Kostiakov模型更加能反映出不同比例生物炭施加下土壤水分入渗过程;生物炭施加比例1%,2%和3%的饱和体积含水量分别较0%增加了5.05%,8.33%和9.85%,饱和导水率分别减少了45.71%,62.86%和74.28%,生物炭施加提高了土壤持水能力;Van Genuchten中1%,2%,3%的参数a较0%分别减少了31.90%,29.25%,19.23%;n分别减少了0.28%,0.16%,0.66%;生物炭施加比例1%,2%和3%的饱和扩散率分别较0%减少了58.46%,77.96%和89.28%.生物炭施加改良了土壤结构,增加了土壤体积含水量,提高了土壤持水性能.

Biochar applied in soil can alter characteristic parameters of soil water migration in Heilu soil in the southern Ningxia mountain region.A typical Heilu soil in the region was selected to the study object.Then,a soil amendment-biochar was added into one-dimensional vertical and horizontal soil columns in four proportions,such as 0%,1%,2%and 3%,to explore the change in soil water transport characteristics,namely,infiltration rate,saturated volumetric water content,saturated hydraulic conductivity,and saturated diffusivity.The results show that soil water content in the soils with 1%,2%and 3%biochar is increased by 2.98%,6.45%and 7.94%compared with the plain soil.The Phi-lip model can reflect soil water transport process in different biochar mixing proportions more exactly than the Kostiakov model.The saturated volumetric water content in the amended soils with 1%,2%and 3%biochar is increased by 5.05%,8.33%and 9.85%,respectively,and the saturated hydraulic conductivity is decreased by 45.71%,62.86%and 74.28%,respectively.The parameter a in the Van Gencuhten model for the amended soils with 1%,2%,and 3%biochar is reduced by 31.90%,29.25%,and 19.23%,and the parameter n in the model is reduced by 0.28%,0.16%,and 0.66%,respectively.The saturated diffusivity in the amended soils with 1%,2%,and 3%biochar is reduced by 58.46%,77.96%and 89.28%compared with the plain soil,respectively.These facts suggest that biochar can improve soil structure,and can increase soil volumetric water content and improve soil water holding capacity.