轻基质配比对蚬木容器苗生长的影响

Effects of light substrate ratio on the growth of container seedlings of Excentrodendron hsienmu

[目的]筛选适宜蚬木容器苗生长的育苗基质配方,为其容器苗的培育提供依据。[方法]以椰糠、泥炭土、珍珠岩和蛭石为原料,按照9∶1∶0∶0、8∶2∶0∶0、7∶3∶0∶0、8∶1∶0.5∶0.5、7∶1∶1∶1、6∶1∶1.5∶1.5的体积比配制基质(L_(1)~L_(6)),分别以椰糠(CK_(1))、黄心土(CK_(2))和椰糠+3.0 kg·m^(-3)缓释肥(CK 3)为对照。采用单因素随机区组设计,比较不同配比基质的理化性质;测定不同配比基质处理下蚬木容器苗的生长指标、叶面积和SPAD值,并进行相关性分析与隶属函数值计算。[结果](1)L_(1)~L_(6)处理基质的干容重为0.128~0.192 g·cm^(-3),总孔隙度为81.207%~86.497%,pH值为6.530~6.995,全氮、全磷和全钾含量分别介于1.135~4.830、0.121~0.274和4.512~6.709 g·kg^(-1)之间,均适合蚬木生长。(2)2021年3月L_(1)~L_(6)处理平均苗高为28.58~32.29 cm,平均地径为5.02~5.32 mm,各处理苗木的生长总体上优于CK_(1)和CK_(2)。(3)相关性分析表明,苗木地下部分鲜物质量、地下部分干物质量、一级侧根数与基质干容重、湿容重呈极显著负相关,与总孔隙度、非毛管孔隙度、pH值呈极显著或显著正相关,一级侧根数与全磷含量呈显著正相关。(4)隶属函数值综合评价结果表明,不同配比基质处理下苗木质量平均得分依次为:L_(6)>L_(2)>CK 3>L_(1)>CK_(1)>L_(3)>L_(4)>L_(5)>CK_(2)。[结论]比较隶属函数值评分结果,并综合不同基质的理化性质及其对苗木生长的影响,选择椰糠∶泥炭土∶珍珠岩∶蛭石为6∶1∶1.5∶1.5和8∶2∶0∶0的配比基质(L_(6)和L_(2)处理)作为蚬木容器苗的最适宜基质。

[Purpose]The seeding substrate formula suitable for the growth of Excentrodendron hsienmu seedlings was screened out to provide a basis for the cultivation of E.hsienmu container seedlings.[Method]Coconut husk,peat soil,perlite,and vermiculite were used as raw materials to prepare substrates(L_(1)-L_(6))with volume ratios of 9∶1∶0∶0,8∶2∶0∶0,7∶3∶0∶0,8∶1∶0.5∶0.5,7∶1∶1∶1,and 6∶1∶1.5∶1.5.Coconut husk(CK_(1)),yellow soil(CK_(2)),and coconut husk+3.0 kg·m^(-3) slow-release fertilizer(CK 3)were used as controls.A single-factor randomized block design was used to carry out the container seedling test.The physical and chemical properties of the substrate and the growth index,leaf area,and chlorophyll content of the seedlings were measured.Correlation analysis and membership function value calculations were carried out.[Result](1)The dry bulk density of L_(1)-L_(6) treatments was 0.128-0.192 g·cm^(-3),the total porosity was 81.207%-86.497%,the pH value was 6.530-6.995,and the contents of total nitrogen,total phosphorus and total potassium were 1.135-4.830,0.121-0.274,and 4.512-6.709 g·kg^(-1),respectively,which were suitable for the growth of E.hsienmu under different substrate treatments.(2)Under L_(1)-L_(6) treatment,the average container seedling height of E.hsienmu seedlings was 28.58-32.29 cm,the average ground diameter was 5.02-5.32 mm in March 2021.The growth of container seedlings in each treatment was generally better than that of CK_(1) and CK_(2).(3)Correlation analysis showed that fresh weight of the underground part,dry weight of the underground part,primary lateral root number of the seedlings highly significantly negatively correlated with dry bulk density,and wet bulk density of the substrate,and highly significantly or significantly positive correlated with total porosity,non-capillary porosity,and pH value.Primary lateral root number of the seedlings significantly positive correlated with total phosphorus content.(4)The comprehensive evaluation results of the membership function values showed that the order of seedling growth quality under different substrate treatments from high to low was L_(6)>L_(2)>CK 3>L_(1)>CK_(1)>L_(3)>L_(4)>L_(5)>CK_(2).[Conclusion]The membership function values were compared,and the physicochemical properties of different substrates and their effects on seedling growth were considered.Coconut husk:peat soil:perlite:vermiculite ratios of 6∶1∶1.5∶1.5 and 8∶2∶0∶0(L_(6) and L_(2) treatments)were selected as the optimal substrates for E.hsienmu container seedlings.