大别山北麓林下间作茶叶对改善土壤水分入渗的影响

Impacts of intercropping tea trees under forest on soil water infiltration in the northern of Dabie Mountains

土壤水分入渗是受土地利用类型(覆盖)变化影响显著的水文过程。为探明坡式经济林开发对土壤水分入渗的影响及其影响因素,该研究选取安徽省金寨县4种开发栽培模式(板栗经济林、板栗+茶间作、油茶经济林和油茶+茶间作,以杂木林为对照),选取Philip、Kostiakov、Kostiakov-lewis和Horton 4种模型对其在不同开发栽培模式下的适用性进行评价。结果表明:1)坡式经济林开发为板栗经济林、板栗+茶间作、油茶经济林和油茶+茶间作后,土壤水分入渗性能显著降低,平均入渗率、初始入渗率和稳定入渗率下降幅度分别为46.14%~64.88%、39.60%~58.97%和49.88%~72.84%。初始入渗率和稳定入渗率的大小排序为杂木林、板栗+茶间作、油茶+茶间作、板栗经济林、油茶经济林;而平均入渗率在板栗+茶间作和油茶+茶间作中无显著性差异(P>0.05)。2)相关性及通径分析表明,力稳性>5.00 mm粒级团聚体、水稳性平均重量直径和力稳性平均重量直径与土壤水分入渗性能(初始入渗率、平均入渗率、稳定入渗率)呈显著正相关(P<0.05),是影响土壤水分入渗特征的主要因素,且力稳性>5.00 mm团聚体是主要影响因子。3)Kostiakov模型最适合描述土壤入渗速率的特征。研究结果可为研究区开发栽培模式的选择提供参考。

Soil water infiltration,a hydrological process,can be significantly dominated by land use types(vegetation cover).There is also some impact on the formation and distribution of slope runoff,soil moisture regulation,water conservation,and soil conservation.This study aims to investigate the impact of slope economic forest development on soil water infiltration,in order to determine the main influencing factors on the soil water infiltration.Field surveys and visits were carried out as well.Four cultivation modes were selected from Jinzhai County,Anhui Province,including Castanea Mollissima forest,Castanea Mollissima with tea interplanting,Camellia Oleifera forest,and Camellia Oleifera with tea interplanting,with Miscellaneous Wood forest as the control.Indoor experiments were then combined with field investigations.A systematic analysis was implemented to explore the main influencing factors of soil water infiltration,including the soil bulk density(BD),porosity,soil mechanical composition,soil organic matter(SOM),soil aggregate structure,and soil water infiltration characteristics(Initial infiltration rate,steady infiltration rate,average infiltration rate)under different cultivation modes.Meanwhile,four models were selected to evaluate their applicability under different cultivation modes,including Philip,Kostiakov,Kostiakov-Lewis,and Horton.The results showed:1)The soil water infiltration significantly decreased after the cultivation of slope economic forests into Castanea Mollissima forest,Castanea Mollissima with tea interplanting,Camellia Oleifera forest and Camellia Oleifera with tea interplanting.The average infiltration rate(AIR),initial infiltration rate(IIR),and stable infiltration rate(SIR)decreased by 46.14%to 64.88%,39.60%to 58.97%,and 49.88%to 72.84%,respectively.The initial infiltration rate and stable infiltration rate were ranked in the descending order as follows:Miscellaneous Wood forest,Castanea Mollissima with tea interplanting,Camellia Oleifera with tea interplanting,Castanea Mollissima forest,Camellia Oleifera forest;There was no significant difference in the average infiltration rate between Castanea Mollissima with tea interplanting and Camellia Oleifera with tea interplanting(P>0.05).2)Miscellaneous Wood forests shared the higher soil porosity,soil organic matter,clay content,mean weight diameter(MWD),and geometric mean diameter(GMD),indicating large aggregate content,higher soil stability,and lower bulk density and fractal dimension(D),compared with Castanea Mollissima forest,Castanea Mollissima with tea interplanting,Camellia Oleifera forest,and Camellia Oleifera with tea interplanting;3)The initial,average,and stable infiltration rate were significantly negatively correlated with the soil bulk density,sand content,mechanical stable aggregate 1-2 mm,mechanical stable aggregate 0.5-1 mm,water stable aggregates 1-2 mm,and water stable aggregates 0.5-1 mm(P<0.05).There was a significant positive correlation with the soil organic matter,capillary porosity(CP),non-capillary porosity(NCP),total porosity(TP),powder particles,clay particles,mechanical stable aggregate>5 mm,0.25-0.5 mm,MWD,GMD,D,water stable aggregates>5 mm,2-5 mm,0.25-0.5 mm,MWD,GMD,and D.The path analysis showed that the mechanical stable aggregate>5 mm,water stability aggregate MWD,and mechanical stable aggregate MWD were the main influencing factors on soil water infiltration,while the mechanical stable aggregate>5 mm was the main influencing factor.3)The goodness of fit of the infiltration was ranked in descending order as follows:Kostiakov model>Philip model>Horton model>Kostiakov-Lewis model,according to the coefficient of determination R2,RRMSE,CRM,and CE.The Kostiakov model was the most suitable to describe the actual situation of soil infiltration in the northern Dabie Mountains.The findings can also provide a strong reference for the cultivation modes.