保水剂对4种木本植物生长及根系形态的影响

摘要

[Background] Water is the main limiting factor of plant growth and ecological restoration in vegetation afforestation in arid area.The inefficient use of soil moisture will lead to the waste of soil water in vegetation construction,soil dry layer,low ecological efficiency and poor vegetation growth.The application of water-retaining agents in arid zones can compensate for these shortcomings,and the best use of it for different plants needs to be studied.[Methods] In order to study the optimal amount of water-retaining agent for the growth of afforestation vegetation in arid area,4 kinds tree species conserving soil and water,including two kinds of shrubs (Syzygium aromaticum and Swida alba Opiz) and two kinds of trees (Pinus tabulaeformis Carr,and Fraxinus chinensis Roxb.) were selected as the research object.During the growth period,the height and ground diameter of the plants were measured with steel tape and vernier calipers,and the soil water content was measured with a soil moisture meter.Then the plants were separated from the soil,the plants were washed and dried,and the root length,root surface area,root mean diameter,apical number and bifurcation number were analyzed by WinRHIZO root scanner and data analysis software.And the aboveground biomass and underground biomass were weighed.[Results] The soil water content of the test group was higher than that of the control group,and the soil water content increased with the increase of the concentration of the water-retaining agent.For two shrubs,the plant height,ground diameter and root index increased with the increase of water-retaining agent,and the biomass growth rate of clove and red wood was 20.73％-64.40％ and 24.92％-98.21％ respectively.The optimal amount of water-retaining agent was 20 g/plant.The plant height,ground diameter and root index of P.tabulaeformis and white wax decreased with the increase of the concentration of water retaining agent,the growth rate of biomass was 10.1％-56.58％ and 7.04％-35.61％ respectively.The higher concentration of water-retaining agent had inhibitory effect on the growth,and the two best water-retaining agent dosages were 5 g/plant and 10 g/plant.[Conclusions] The application of the water-retaining agent significantly affected plant growth and root morphology changes.5-50 g/plant of the water-retaining agent applied to the clove and red Ruimu can promote the growth,the most suitable amount of 20 g/plant,Chinese pine water-retaining agent application range of 5-20 g/plant,the most suitable amount of 5 g/plant,white wax water-retaining agent application range of 5-30 g/plant,the most suitable amount of 10 g/plant.%为了研究干旱区造林植被生长所需的最适保水剂施用量,选取北方干旱区常用的4种水土保持树种(丁香、红瑞木、油松和白蜡)为研究对象,通过盆栽对照实验,研究在5个保水剂用量下,4种植物的株高、地径、生物量和根系形态的变化.结果表明:施用保水剂的试验组,其土壤含水量均比对照组高,且土壤含水量随着保水剂浓度的升高而提高.对丁香和红瑞木2种灌木而言,株高、地径及根系各指标随着保水剂的增加,呈现先增大后减小趋势,其生物量增长幅度分别为20.73％ ～64.40％和24.92％～98.21％;乔木树种油松和白蜡株的高、地径及根系各指标,其随着保水剂浓度的增大而减小,生物量增长幅度分别为10.1％ ～56.58％和7.04％ ～35.61％,较高浓度保水剂对其生长出现抑制作用.保水剂对2种灌木生长的促进作用＞2种乔木,且灌木的保水剂可受用范围更为广泛.在北方干旱区植被造林中,丁香和红瑞木的最适保水剂用量均为20 g/株,油松为5 g/株,白蜡为10 g/株.该研究为中国北方干旱区植被造林,提供科学依据和参考.