寒区紫花苜蓿晚播对根系性状及越冬性能的影响

Effect of late sowing on root traits and overwintering performance of alfalfa in cold regions

为了探索紫花苜蓿在齐齐哈尔地区的最晚播种期,试验以龙牧803紫花苜蓿为试验材料,通过设定不同的晚播期研究其对紫花苜蓿的出苗天数、越冬率、根系生长发育及草产量的影响。结果显示,不同播种期的出苗天数不同,7月8日至7月29日播种的苜蓿出苗天数最短,为4 d。除在7月1日播种的T1外,紫花苜蓿的根颈直径、根颈入土深度、主根直径、主根长度、须根数、分枝数与越冬率均随播种期的延后呈下降的趋势。7月8日播种的紫花苜蓿产草量最高,为11 302.79 kg/hm^(2)。播期越晚,产量越低。研究表明,在齐齐哈尔地区紫花苜蓿能够安全越冬的最晚播期宜在7月22日之前。

In order to explore the latest sowing date of alfalfa in Qiqihar,Longmu 803 alfalfa was used as experimental material,to study the effect of alfalfa on emergence days,overwintering rate,root growth and grass yield by setting different late sowing periods.The results showed that the number of emergence days of alfalfa sown from July 8 to July 29 was the shortest,which was four days.The diameter of root neck,depth of root neck into soil,diameter of main root,length of main root,number of fibrous roots,number of branches and wintering rate of alfalfa all decreased with the delay of sowing date except T1 sown on July 1.The forage yield of alfalfa sown on July 8 was the highest,which was 11302.79 kg/hm^(2) on July 8,and the yield of other treatments decreased with the sowing date.The study indicates that the latest sowing date for alfalfa to survive the winter in Qiqihar should be before July 22.