摘要
科学确定沙地土壤养分指标并进行土壤养分评价,对提升沙地土壤肥力有着重要意义。以翁牛特旗乌丹镇林场幼龄18 a、中龄26 a、成熟32 a,3个不同林龄的榆树作为研究对象,分析0~10,10~20和20~40 cm土层的土壤理化性质和土壤酶的变化特征,用熵权法对土壤养分质量进行综合评价。熵权法采用主成分分析法筛选指标最小数据集(MDS),计算各土壤样本与最优及最劣样本的加权欧氏距离,计算土壤养分综合评价指数。结果表明:不同林龄土壤养分和酶活性指标存在不同的差异情况,在10个养分指标和3个生长指标中,MDS由速效氮、速效钾、多酚氧化酶3个指标组成,同一指标不同林龄下差异显著。表现为幼龄林:速效氮(0.47)>速效钾(0.09)>多酚氧化酶(0.16);中林龄:速效氮、多酚氧化酶(1)>速效钾(0.31);成熟林:速效钾(0.84)>多酚氧化酶(0.65)>速效氮(0)。根据土壤指标熵权得分情况,在不同林龄阶段适当控制或调整化肥施用比例和周期,以更好地改善当地榆树长势并提升土壤肥力。
[Background]Horqin sandy land is a national key ecological environment construction area and a typical ecological fragile area.In recent years,wind erosion and soil erosion are serious in this area.Elm forest is the most stable vegetation type in sandy land.It is not only the climax community of vegetation succession in sandy land,but also the ecological tree species most suitable for local climate conditions.However,due to the limitation of soil moisture and nutrients,the ecological function degradation and low efficiency of some elm forests has become increasingly prominent with the growth of elm forests.At present,the focus of vegetation restoration and ecological reconstruction in sandy land should be on the management of the existing plantation.[Methods]Taking young 18 a,middle-aged 26 a,mature 32 a elm trees of three different forest ages in Wengniute banner as the research object,the nutrient change characteristics of 0-10,10-20 and 20-40 cm soil layers were analyzed.With the PC A-TOPSIS evaluation system,the data sets were firstly subjected to dimension reduction analysis using principal component analysis method,and the dynamic scores of soil nutrients at different forest ages were further discussed and evaluated combined with TOPSIS method,and then the nutrient indexes of the appropriate age for the sandy land were screened out.The nutrient index and plant growth index of MDS(minimum data set)were calculated by weighted TOPSIS,and the result score was calculated.[Results]The cumulative PCA contribution rates of soil available nitrogen,available potassium and polyphenol oxidase were all greater than 0.9,indicating that they had a positive effect on soil quality,and the more the index,the better.The highest available nitrogen score in Z treatment(26 a)was 1,followed by Y treatment(18 a),which was 0.467.The highest value of soil available potassium was 0.84 in C treatment(32 a).The highest value of soil polyphenol oxidase score was Z treatment(1),followed by C treatment(0.645),and the lowest value was Y treatment(0.159).Result The score linear regression passed the F test(F=398.629,P<0.05),R^(2)=0.996,and the TOPSIS score of available nitrogen represented 99.6%of the growth index,indicating that available nitrogen was the nutrient factor next to available potassium.Polyphenol oxidase R^(2)=0.990,which had a high regression fitting degree with growth factors,and the score value was reliable after verification,and can also be used as a positive effect index of elm forest soil.[Conclusions]There are varied different differences in soil nutrient and enzyme activity indexes at different forest ages,and the same index presents has significant differences at different forest ages.According to the entropy weight score of soil index,the proportion and cycle of chemical fertilizer application should be properly controlled or adjusted at different forest ages to better improve the growth of local elm trees and enhance the soil fertility.
作者
李俊杰
李钢铁
麻云霞
张月欣
胡博
张金旺
王月林
LI Junjie;LI Gangtie;MA Yunxia;ZHANG Yuexin;HU Bo;ZHANG Jinwang;WANG Yuelin(College of Desert Control,Inner Mongolia Agricultural University,010020,Hohhot,China;Tongliao Forestry Research Institute,028000,Tongliao,Inner Mongolia,China;Inner Mongolia Forestry and Grassland Seedling Station,010051,Hohhot,China)
出处
《中国水土保持科学》
CSCD
北大核心
2022年第5期17-23,共7页
Science of Soil and Water Conservation
基金
国家自然科学基金“基于菌根技术的浑善达克沙地榆树生态适应性机制研究”(RZ2000001669)。
关键词
榆树
土壤养分
土壤酶活性
主成分分析
熵权法
Ulmus pumila
soil nutrients
soil enzyme activity
principal component analysis
entropy weight method
作者简介
第一作者:李俊杰(1996-),男,硕士研究生。主要研究方向:沙区植物资源保护与利用。E-mail:liggtx@126.com;通信作者:李钢铁(1963-),男,教授,博士生导师。主要研究方向:沙区植物资源保护与利用。E-mail:13848817183@163.com。
