盐生境下硅对坪用高羊茅生物学特性的影响

干旱半干旱区草坪绿地的长期灌溉容易引发土壤次生盐渍化,提高草坪草在盐生境下的生长发育能力是应对土壤次生盐渍化的主要途径之一.采用盆栽试验研究了盐生境下硅对坪用高羊茅(Festuca arundinaea)生物学特性的影响.结果表明,向盐生境土壤中添加不同浓度硅均提前高羊茅出苗时间2d,加快出苗速率,增加出苗总数,提高保苗率,且总出苗率和保苗率随着硅浓度增加而显著增大(P＜0.05),这说明盐生境下向土壤添加硅改善了幼苗完全死亡的现象.盐生境下硅显著增加了高羊茅叶长,株高和分蘖数,但对叶宽影响不显著,说明硅能够促进高羊茅生长,但对草坪绿地的质地影响不大.虽然硅能显著增加高羊茅总生物量(P＜0.05),但较低浓度时促进其茎叶生长,高浓度促进其根系生长.硅在高羊茅体内的沉积量随施入硅增加而增大,但其茎叶和根系内硅含量不超过3.0％,且根系内硅含量约为茎叶内硅含量的2倍.结果显示,硅提高了坪用高羊茅在盐生境下的适应能力,这为以后草坪绿地管理中应对土壤潜在盐渍化的问题提供了一定的科学依据.

Effect of silicon supply on Tall Fescue (Festuca arundinacea) growth under the salinization conditions

The continual irrigation is one of the important measures to maintain healthy and sustainable use of turf in the arid and semi-arid regions, however, it enable soil to develop possibly soil secondary saline-alkalization. Therefore, it is an urgently scientific issue in the turf management to improve the ability of turf grass to healthy growing in the soil salinization environments. A pot experiment was used to investigate the effect of Si supply on the biological properties of Tall Fescue (Festuca arundinacea) growing in the salinization conditions. This study indicated that silicon supplies made the initial time of seed emergence of tall fescue bring forward two days, shortened the duration of emergence, increased the total seedling rate and the seedling survival rate. The total emergence and seedlings survival rate of Tall Fescue significantly increased with the increase of Si supply (P <0.05), implying that silicon supplies increased the viability of Tall Fescue seedling in the salinization conditions, meanwhile, Tall Fescue seedling died when silicon did not add to the soil. Silicon supplies significantly increased the height, leaf length and tiller number per plant in tall fescue, but did not affect on leaf width, indicating that silicon supplies encouraged the tall fescue growth but did not affect the turf quality. This study also indicated that silicon supplies increased the plants biomass, indicating that the low silicon supplies mainly contributed to shoot growth and the high silicon supplies mainly contributed to root growth, and this implied that the shoots growth was more sensitive than roots growth of tall fescue. Both the silicon content in roots and shoots increased with the increase of silicon concentration, and they were below 3.0%. Silicon content in roots was double that in shoots. This study suggested that silicon supplies improved the suitability of Tall Fescue in the soil salinization environments, which would provide the useful information for future turf management when turf managers face the potential of soil salinization.