杨树林下养鸡对土壤团聚体及理化性质的影响OA

This study aims to investigate the effects of under-forest chicken farming on the soil aggregates and physicochemical properties.A poplar plantation with 2 years of under-forest chicken farming at Youlin Forest Farm in Guanshan Town,Suining County,Xuzhou City,Jiangsu Province was selected as the study site.High-density,medium-density,and low-density farming zones were established at increasing distances(0-10 m,10-20 m,and 20-30 m,respectively)from the chicken shed,while an adjacent poplar plantation without chicken farming served as the control.Soil aggregates and physicochemical properties were analyzed across three soil layers(0-10 cm,10-20 cm,and 20-40 cm).The results showed that compared with the control,after 2 years of under-forest chicken farming,the proportion of water-stable macroaggregates(R0.25)in the 0-10 cm soil layer increased by 13.2%-21.2%;the mean weight diameter(MWD)and geometric mean diameter(GMD)of water-stable aggregates increased by up to 39.4%and 118.8%,respectively,while the percentage of aggregate destruction(PAD)decreased by up to 62.0%.These changes diminished with the decrease in farming density and the increase in soil depth.The aggregate stability was most significantly enhanced in the surface soil near the chicken shed(PC1),whereas changes in the area farther away(PC3)were mild.Chicken farming increased organic matter content and reduced pH in the 0-10 cm soil layer.Correlation analysis revealed that organic matter was the primary factor driving improved stability of soil aggregates.However,chicken farming also led to increased soil bulk density and reduced porosity.Overall,under-forest chicken farming primarily enhances soil organic matter through manure input,thereby improving the formation and stability of soil macroaggregates.However,chicken trampling triggered by high-density chicken farming leads to an increase in soil bulk density and a decrease in soil porosity.Therefore,optimizing farming density is crucial for regulating soil structure and physicochemical properties and for maintaining and enhancing the long-term fertility of poplar plantations.