准噶尔盆地主要农田防护林的生物量及养分分布特征

Distribution Characteristics of Biomass and Soil Nutrient in Main Shelterbelt in Junggar Basin

研究准噶尔盆地主要农田防护林林下土壤养分变化情况,以及林木各组分养分元素含量和生物量特征。以准噶尔盆地主要农田防护林树种新疆杨、白榆和沙枣为研究对象,分析了各林地不同土层土壤有机质、全氮、全磷、全钾含量、林木根枝叶中有机碳、N、P、K含量和生物量。结果表明:1)净生产力从大到小依次为新疆杨(30.20t·hm^(-2))>白榆(21.30t·hm^(-2))>沙枣(13.32t·hm^(-2)),3树种各组分生物量中树干生物量最大,其中新疆杨树干生物量所占比例最高(69.61%)。2)沙枣的有机碳(48.52g·kg^(-1))和N平均含量(20.45g·kg^(-1))最高,3树种P含量(1.86~2.18g·kg^(-1))相差不大,新疆杨的K含量(7.42g·kg^(-1))>其他树种;有机碳含量表现为枝中最高,P含量在根和叶中最高,K含量在叶中最高。3)5个深度(0~20、20~40、40~60、60~80、80~100cm)的土壤有机质平均值为白榆林地(0.76g·kg^(-1))>沙枣林地(0.69g·kg^(-1))>新疆杨林地(0.58g·kg^(-1)),全氮平均值为沙枣林地(0.52g·kg^(-1))>新疆杨林地(0.45g·kg^(-1))>白榆林地(0.21g·kg^(-1)),全磷平均值为沙枣林地(0.98g·kg^(-1))>新疆杨林地(0.91g·kg^(-1))>白榆林地(0.85g·kg^(-1)),全钾平均值为新疆杨林地(13.55g·kg^(-1))>沙枣林地(13.49g·kg^(-1))>白榆林地(12.06g·kg^(-1)),对土壤不同土层而言,3树种林下土壤养分0~20cm土层均高于其他土层,随土层厚度增加土壤养分减少,3树种林下土壤全磷和全钾平均含量属中高水平,全氮和有机质平均含量属低水平。表明不同树种土壤养分和林木各组分养分元素含量大小次序不相同,为防护林各树种养分管理提供依据。

In order to provide theoretical basis for the high yield management of shelterbelt,the changes of soil nutrients in shelterbelt,the contents of nutrient elements in trees,and the characteristics of biomass in Junggar Basin were studied.Three main tree species used in shelterbelt were selected as research objects,including Populus alba,Ulmus pumila,and Elaeagnus angustifolia.The contents of the nutrients in different soil layers and tree leaves and roots were analyzed,such as organic matter,nitrogen,phosphorus,and potassium.Biomass of tree leaves and roots was measured.The results indicated that 1）the order of the net productivity was P.alba（30.20t·hm^（-2））U.pumila（21.30t·hm^（-2））E.angustifolia（13.32t·hm^（-2））.The biomass of tree trunk was the largest in all the three species,in which P.alb had the highest percentage（69.61%）.2）The the highest average contents of soil organic matter（83.65g·kg^（-1））and soil total nitrogen（20.45g·kg^（-1））were found in E.angustifolia.There were no significant differences in total phosphorus among three species,ranging from 1.86 to 2.18g·kg^（-1）.Total potassium content（7.42g·kg^（-1））in P.alba was higher than others.The content of organic matter was the highest in the branches.Total phosphorus content in the roots and leave was the highest.Total potassium content in the leaves was the highest.3）The orders of the average soil nutrients in five soil layers（0-20,20-40,40-60,60-80,and 80-100cm）were organic mater：U.pumila（0.76g·kg^（-1））E.angustifolia（0.69g·kg^（-1））P.alba（0.58g·kg^（-1））,total nitrogen：E.angustifolia（0.52g·kg^（-1））P.alba（0.45g·kg^（-1））U.pumila（0.21g·kg^（-1））,total phosphorus：E.angustifolia（0.98g·kg^（-1））P.alba（0.91g·kg^（-1））U.pumila（0.85g·kg^（-1））,total potassium：P.alba（13.55g·kg^（-1））E.angustifolia（13.49g·kg^（-1））U.pumila（12.06g·kg^（-1））.Soil nutrients of 0-20 cm soil layer was higher than others in three tree species.Soil nutrient contents decreased with the increase of soil depth.The average contents of total phosphorus and total potassium were in medium to high level.The average total nitrogen and organic matter were in low level in the undergrowth soil of the three tree species.Therefore,the contents of the nutrients in different soils and trees were different.The results would provide theoretical basis for nutrient management of shelterbelt.