红壤丘陵区种植茶树和柑橘对土壤肥力和水土流失的影响

Effects of Planting Tea Trees and Citrus Trees on Soil Fertility and Soil and Water Loss in the Red Soil Hilly Region

为探讨经济林种植对土壤肥力和水土保持的影响,以浙江省常山县红壤丘陵区种植茶树和柑橘10年后的园地为对象,并以祼地为对照,定位研究了水土流失量,采样并分析了0~10 cm土壤容重、孔隙度、速效氮磷钾和不同团聚体组分碳氮含量。结果表明:种植茶树和柑橘10年后,土壤容重显著下降(P<0.05),土壤孔隙度、田间持水量、有机碳、有效磷、速效钾和碱解氮含量显著提高(P<0.05);土壤大团聚体有机碳含量大小排序为柑橘园>茶园>祼地,土壤中团聚体、微团聚体、粉粒的有机碳、氮含量大小表现均为茶园>柑橘园>裸地,不同处理间的差异达显著水平(P<0.05);茶园土壤黏粒有机碳、氮含量显著高于柑橘园、祼地(P<0.05);与祼地相比,柑橘园和茶园年径流深显著降低了87.66%、92.25%(P<0.05),年土壤流失量显著减少了95.93%、98.78%(P<0.05)。试验区年径流深、年土壤流失量与土壤有机碳、总孔隙度、田间持水量之间具有极显著或显著负相关(P<0.01,P<0.05),与土壤容重具有显著正相关(P<0.05)。综上,茶树和柑橘种植有利于提高土壤肥力,降低水土流失,其中种植茶树的效果优于柑橘。

In order to explore the effect of economic forest planting on the soil fertility and soil and water conservation,the garden plots planted with tea trees and citrus trees for 10 years in the red soil hilly area of Changshan County in Zhejiang Province were taken as the object,and the bare land was taken as the control group.Then,the orientation research on the amount of soil and water loss was carried out,and the volume weight of soil,soil porosity,rapidly available nitrogen,phosphorus and potassium,and carbon and nitrogen contents in different aggregate components in 0−10 cm soil layer were sampled and analyzed.The results showed that:after planting tea trees and citrus trees for 10 years,the volume weight of soil decreased significantly(P<0.05),and the soil porosity,field water-holding capacity,and the contents of organic carbon,available phosphorus,rapidly available potassium and alkaline hydrolysis nitrogen increased significantly(P<0.05).The content of organic carbon in soil macro-aggregates was in the order of citrus orchard>tea garden>bare land.The contents of organic carbon and nitrogen in soil aggregates,micro-aggregates and soil silt particles were in the order of tea garden>citrus orchard>bare land,and the differences among different treatments were significant(P<0.05).The contents of organic carbon and nitrogen in soil clay in tea garden were significantly higher than those in citrus orchard and bare land(P<0.05).Compared with the bare land,the depth of annual runoff in the citrus orchard and tea garden was significantly reduced by 87.66%and 92.25%(P<0.05),and the amount of annual soil loss was significantly reduced by 95.93%and 98.78%(P<0.05).The depth of annual runoff and the amount of annual soil loss in the experimental area had extremely significant or significant negative correlations with soil organic carbon,total porosity and field water-holding capacity(P<0.01,P<0.05),while had high positive correlation with the volume weight of soil(P<0.05).In summary,the planting of tea trees and citrus trees was conducive to improving the soil fertility and reducing the soil and water loss,and the effect of planting tea trees was better than that of citrus trees.