不同土壤含水量对根茎冰草幼苗生长发育的影响

EFFECT OF SOIL WATER CONTENT ON SEEDLINGS GROWTH OF Agropyron michnoi Roshev.

本研究采用盆栽试验方法,研究了不同土壤含水量对根茎冰草种子萌发出苗和幼苗生长发育的影响。土壤含水量共设5个处理,分别为26%2、1%、17%、12%、7%。试验时间共60d。结果表明:土壤含水量17%为种子萌发出苗的最适含水量,出苗率可达96%,土壤含水量7%时,根茎冰草种子不能萌发出苗。土壤含水量对根茎冰草幼苗生长发育也有明显影响,土壤含水量21%时,最先达到分蘖期;土壤含水量12%时,基生叶片最长,可达31.0cm,生长速度最快,为0.52cm/d,地上生物量最高,达0.18g。随着土壤含水量的降低,根长度增加,根尖数增多,沙套粗度降低,其中土壤含水量12%时,各项指标的测定值达到最大,根系总体积为0.06cm3,表面积为4.98cm2,地下生物量为0.35g,占总体生物量的66%,根尖数达到1206个,是土壤饱和含水量26%的3倍。

Soil water content is a crucial factor for the growth of grass.Agropyron michnoi Roshev.was influenced by Soil water content on seedling growth was studied by pot culture experiment.Five soil Samples with water content of 26%、21%、17%、12%、7%.Their water contents were maintained during the whole 60 days＇ experimental periods.The experimental results indicated： When soil water content of 17% own of the highest germinate.The best of rate was 96%.Water content was lower 7%,the seed didn＇t germinate.When soil moisture was 21%,the seedlings reached to tillering stage firstly.The soil water content remained in 12%,Leaf length reached the longest 31.0cm,aboveground biomass reached the highest of 0.18g.As the soil water content reduced,root length and root number was increase,sand rough degree was reduced.Especially,the relative water content of 12% have optimal expression： Root Volume was 0.06 cm3,Surf Area was 4.98 cm2,projection Area was 1.58 cm2,66 percent of total biomass,underground biomass was 0.35 g,The root number reached 1206.it was three times than saturated soil moisture content.