period of frost free的意思|示意

According to the meteorological observation in Minqin Desert Control Experiment Station, variations of frost-free period, low temperature in spring and frozen earth were analyzed.

以甘肃民勤治沙综合试验站数十年气象定点观测资料为基础，统计、分析了民勤荒漠区无霜期、春季低温、冻土层的变化特征。

Change at the annual frost-free period 100-160 days, the distribution of the trend of growing on the grounds east to west.

全年无霜期变化在100—160天之间，分布趋势为由东向西逐渐增长。

The sunshine duration is long, the temperature difference is big, the frost-free period is long, and the annual solar radiation amount is much, which is good for the growth of crops.

日照时间长，昼夜温差大，无霜期长，年太阳能辐射量大，对农作物生长十分有利。