Abstract:

By means of randomized block design, a study on the effect of seeding stage, emergence rate, winter survival rate plant height and phenology and grass yield of 2 consecutive years, and the following year with FW/DW Ratio, Stem/Leaf Ratio of alfalfa was conducted under different sowing dates in Saiwusu, Ordos, in 2009. The results showed that there was a significant positive correlation among emergence stage, emergence rate and sowing dates; when it was given a earlier sowing dates, the root crown would be more thicker, and its depth would be deeper, and the wintering ability in the very year would also be stronger; growth period would be earlier followed with the earlier sowing dates; when it was sowed earlier, the higher grass yield of the first year would be higher. Different sowing dates made little influence on FW/DW Ratio, Stem/Leaf Ratio. The local optimum sowing dates was autumn(before Mid-September).