Effects Of Jujube Planting Years On Soil Physical And Chemical Properties In Sandy Area

In this study,the soil of jujube orchard with different planting years that in the 14th Division of the Xinjiang Production and Construction Corps,which was located in sand area,was used as the experimental material.Some indexes of soil physical and chemical properties such as the soil bulk density,total porosity,water content,pH,salt content,organic matter,large amount of elements,trace elements and organic carbon composition and their characteristics of the date of cultivation is 4 years,6 years,8 years and 10years were determined and analyzed of its changing characteristics.Further more,the comprehensive effects of planting years of jujube trees on soil physical and chemical properties in sandy area were analyzed and discussed.The aimed is to explore the effect of vegetation on soil improvement in sandy area,and to provide theoretical reference for soil remediation in sandy land of Southern Xinjiang.The main results are as follows:(1)The planting years have significant influence on the soil bulk density,specific gravity and total porosity of jujube garden.The planting years of jujube garden in 4-10 years,with the increase of planting years,the soil bulk density of jujube garden generally descends in the range of 0-40cm soil layer,from1.45g/cm~3to 1.38g/cm~3,and in the range of 40-60cm soil,the soil bulk density of jujube garden decreases first and then rises.In the range of 0-20cm soil,the proportion of soil and total porosity in the jujube garden showed a trend of decreasing and then rising,but in the range of the 20-60cm soil layer,the trend of the soil decreased first and then descended.The results showed that the longer the planting time of jujube trees,the better the physical properties of soil.(2)The soil pH value of jujube orchard in 4 years was significantly different from that in other years,thatis,with the increase of planting years,the soil pH value decreased obviously,from 7.70 to 7.58.The soil water-soluble salt content in jujube orchard increased firstly and then decreased with the increase of planting years.(3)The contents of organic matter,alkali-hydrolyzed nitrogen,available phosphorus and trace elements in soil of jujube orchard increased first and then decreased with the increase of planting years,but the content of available potassium had no significant change.The nutrient content in soil layer showed apparent aggregation.Although the soil nutrient content of jujube orchard in the study area varies with the planting years,the contents of organic matter,alkali-hydrolyzed nitrogen,available iron,available zinc and available manganese in the soil of jujube orchard are still deficient,only the available phosphorus and available potassium are higher.(4)The change of soil organic carbon content and soil organic carbon density in jujube orchard increasedfirst and then decreased with the increase of planting years,but the activity of soil carbon pool increased with the increase of planting years in jujube orchard.The planting years of jujube trees had no significant effect on the soil organic carbon storage,but the soil organic carbon storage increased gradually with the decrease of soil layer,from 3.55g/kg to 9.13 g/kg.