To investigate the effect of steel slag used as substrate on the rooting of Hydrangea macrophylla cuttings, and to develop a new mixed substrate that can partially replace conventional cutting substrates and realize the high-efficient utilization of solid waste, we examined the physical and chemical properties of different mixed substrates containing 10% (T1), 20% (T2), 30% (T3), and 40% (T4) volume fractions of steel slag, and investigated the rooting of H. macrophylla 'Red Beauty' cuttings growing on these substrates, with conventional cutting substrates (peat and perlite) as the control (CK). The results showed that pH value, electrical conductivity, and bulk density of the mixed substrates were significantly higher than those of CK. The aeration porosity of T2 was higher than other treatments, while the total porosity and water holding porosity differed little from others. Both fresh weight and dry weight of all the four treatments were higher than those of CK, with stem diameter being higher than that of CK (except T4), plant height showing no significant difference compared to CK (except T4), and leaf chlorophyll content being significantly lower than CK. Root length ranked as T2>CK>T1>T3>T4, the root surface area and root volume both ranked as T2>T1>CK>T4>T3, the root tip ranked as T2>CK>T1>T4>T3. Both average root diameter and root activity were significantly higher than that of CK, with the highest value being observed in T2. Soluble sugar content in the leaves of T2 was the highest, followed by T4, T3, CK, and T1. The weight ranking of root growth indices was root activity > average root diameter > root volume > root surface area > root tip number > root length. Redundancy analysis indicated that pH value, electrical conductivity, aeration porosity, and water holding porosity of substrates were key factors influencing root growth and development of cuttings. Our results suggested that substrates mixed with 10% to 40% steel slag could be used for H. macrophylla cutting propagation, and 20% (T2) being the best one because it could significantly improve the survival rate, growth status, and root development of cuttings. Steel slag would be a novel substrate to partially replace conventional unrenewable substrates such as peat and perlite for flower seedling propagation, which could reduce agricultural production cost and provide a high-value utilization way of industry solid waste.
为研究钢渣混合基质对大花绣球扦插生根的影响,创制可部分替代常规扦插基质、实现固体废弃物高效利用的新型基质,本试验以常规扦插基质(泥炭+珍珠岩)为对照(CK),研究在其中添加体积分数为10%(T1)、20%(T2)、30%(T3)和40%(T4)钢渣的条件下,混合基质的理化性质及其对大花绣球‘红粉佳人’生根的影响。结果表明: 钢渣混合基质的pH值、电导率和容重均显著高于CK,T2处理通气孔隙度高于其他处理,但总孔隙度和持水孔隙度无显著差异;扦插苗地上部分生长表现为:各处理鲜重和干重均大于CK,茎粗除T4处理外均大于CK,株高除T4处理外与CK相比无显著差异,叶片叶绿素含量均显著低于CK;扦插苗根系生长表现为:根长为T2>CK>T1>T3>T4,根表面积和根体积均为T2>T1>CK>T4>T3,根尖数为T2>CK>T1>T4>T3,各处理平均根直径和根系活力均显著高于CK,且以T2处理最高;扦插苗叶片可溶性糖含量为T2>T4>T3>CK>T1。根系生长发育指标权重排序为:根系活力>平均根直径>根体积>根表面积>根尖数>根长;冗余分析发现,基质pH值、电导率、通气孔隙度和持水孔隙度是影响插穗根系生长发育的关键因子。综上,添加体积分数为10%～40%钢渣的混合基质均能够用于大花绣球扦插育苗,其中以20%(T2)的效果最好,可显著改善插穗成活率、生长状况和根系发育。本研究证实了钢渣作为花卉新型育苗基质部分替代泥炭、珍珠岩等常规不可再生基质的可行性,既可降低农业生产成本,又能实现工业固废的高值化利用。.
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