六种牧草种子大小和播种深度对出苗的影响

西方冰草、沙生冰草、草地早熟禾、绿针茅、粗羊茅及匍茎翦股颖 6种牧草的种子在塑料杯中分 0 .5 cm、0 .75 cm、1.5 cm、3.0 cm和 6 .0 cm的不同深度 ,分别播种在土壤、人工土壤和沙土上。当 p=0 .0 1时 ,土壤 (S) ,种子大小 (SE) ,播种深度 (D) ,S× SE,SE× D和 S× SE×D的相互作用对出苗率的影响均有显著差异。随着播种深度的增加每一种牧草的出苗率都有所降低。西方冰草在所有播种深度下出苗最好 ,而匍茎翦股颖在沙土中出苗最好。西方冰草与沙生冰草在 3.0 cm和 6 .0 cm的播种深度下出苗较好。种子大小还与胚芽鞘长度 (R=0 .96 ,P=0 .0 5 ,3.0 cm播种深度 ) ,苗高 (R=0 .99,P=0 .0 1,3.0 cm播种深度 )和根长 (R=0 .96 ,P=0 .0 1,3.0 cm播种深度 )之间的相关关系显著。土壤对出苗具有显著的影响 (LSD0 .0 5=0 .10 13)。

Effects of seed size and seedling depth on emergence of six perennial grasses

Six perennial grasses, including western wheatgrass (Agropyron smithii) , northern wheatgrass (A. dasystachyum) , kentucky bluegrass (Poa pratensis) , green needlegrass (Stipa viridula), rough fescue ( Festuca scabrella ) and red top ( Agrostis stolonifera ) were seeded seprately at 0.5, 0.75, 1.5, 3.0 and 6.0 cm depth in plastic cups containing Redi earth or sand. The emergence rate of each species decreased with increasing planting depth. Western wheatgrass had the highest emergence at all depths, while red top had the highest emergence on sand and lowest emergence on redi earth. Seed size had a significantly positive relation with the planting depth (LSD 0.05 =0.160 1). Western wheatgrass and Northern wheatgrass had higher emergence at 3.0 and 6.0 cm depths. Seed size also had a significant relationship with length of coleoptiles (R=0.96, P=0.01 at 3 cm depth), shoots (R= 0.99 , P=0.01 at 3 cm depth) and roots (R=0.96, P=0.01 at 3 cm depth). Soils had a significant effect on emergence (LSD 0.05 =0.101 3).