| This article analyzed the growth disciplinarian,the above-ground biomass and the under-ground biomass of alfalfa,and investigated the effects of meteorological factors to the growth of alfalfa.The results showed that alfalfa is suitable well to the climate condition in east Gansu;the ratio of FW/DW is high,and it is favorable for breeding as green forage.Due to the limit of heat energy in early autumn,the third cutting grass ceases growing after divarication period.The requirement of accumulated temperature above 0℃ was about(1 100)℃～1 150℃ in the full growth period of each cutting,thereinto,about 280℃ and 330℃ in sproutingdivarication period in springtime and summertime respectively,about 460℃ in divarication-budding period,and about 360℃ in budding～blooming period.From the first cutting to the third cutting,the yield of alfalfa tends to reduce but the number of divarication tends to increase in turn.Budding period is the key time affecting yield formation. |