不同土壤水分条件下硅对坪用高羊茅种子出苗及生物学特性的影响

水肥耦合不仅可以维持草坪草的正常生长，而且可以减少一定的灌溉量。采用盆栽试验研究了不同土壤条件下硅对坪用高羊茅种子出苗及生长的影响。结果表明，不添加硅时，高羊茅种子适宜出苗时的土壤含水量应为饱和含水量的４５％～６０％，植株生长适宜的土壤含水量应为饱和含水量的７５％以上；当土壤含水量大于或等于饱和含水量的６０％时，添加硅不仅能够提前坪用高羊茅种子的初始出苗时间，缩短集中出苗时期，提高出苗率，而且能够显著促进高羊茅的株高和叶长生长，增加地上和地下生物量（P＜０．０５），而当土壤含水量小于或者等于饱和含水量的４５％时，添加硅对高羊茅种子出苗和生长发育没有明显影响，说明添加硅对坪用高羊茅生长的有益作用受土壤含水量的约束；土壤含水量为饱和含水量的６０％时，添加硅处理中植株的分蘖数、株高、叶长和生物量与对照处理中土壤含水量为饱和含水量的７５％时植株的分蘖数、株高、叶长和生物量差异不显著，说明添加硅能降低高羊茅植株正常生长所需的土壤含水量，有利于节约灌溉量。

Effect of addition of silicon on seed emergence and growth of tall fescue (Festuca arundinacea ) under the different soil moistures

The water and fertilizer coupling benefits the health growth of turf grasses and reduces the irrigation water to some extent.A pot experiment was conducted to determine the effect of addition of silicon on seed emergence and growth of tall fescue(Festuca arundinacea) under the different soil moistures.This study showed that the soil moisture ranging from 45% to 60% of field water capacity was suitable for seed emergence of tall fescue,and the minimal requirement for soil moisture was 75% of field water capacity for plant growth of tall fescue when addition of silicon was unavailable.Addition of silicon enabled seed emergence of tall fescue to become fast,that addition of silicon shortened the time of seed emergence,increased the survival seedling rate,encouraged the plant height and leaf length to grow,and increased the biomass of shoots and roots when soil moisture was 60% of field water capacity or over it.However,addition of silicon did not affect the growth of tall fescue when soil moisture was 45% of field water capacity or below it,implying that the beneficial effectiveness of addition of silicon on tall fescue growth was strongly regulated by the soil moisture environment.This study also showed that tillers per plant,height,leaf length,and total biomass of plants between +Si(addition of silicon) treatments with 60% of field water capacity and-Si(control) treatments with 75% field water capacity was not significantly different,suggesting that addition of silicon reduced the minimal requirement for soil moisture for health growth of tall fescue,and benefited the saving irrigation water.