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一、0℃界线温度 是指日平均气温稳定通过0℃,春季当温度达到这个界线时,说明寒冷已过,土壤开始化冻,草木萌动,秋季日平均气温低于0℃时,说明一切农作物停止生长,并开始枯黄。 二、3℃界线温度 春季日平均气温稳定通过3℃时,冬小麦、韭菜、冬根菠菜可返青,春小麦开始播种;秋季气温降到3℃以下时,作物停止生长,大秋作物叶子变黄。 三、5℃界线温度 春季日平均气温稳定通过5℃时,早春作物开始播种,如早春菜及油料作物等;秋季气温降到5℃以下时,作物生长缓慢。又把每年从春至秋气温维持5℃之间的时期,叫作农耕期。 四、10℃界线温度 春季日平均温度稳定通过10℃,是各种农作物播种后能够生长的热量指标,秋季日平均气温低于10℃,作物光合作用加强,成熟速度加快。
First, the 0 ℃ boundary temperature refers to the daily average temperature stable through 0 ℃, when the temperature reaches this threshold in spring, indicating that the cold has passed, the soil began to freeze, vegetation germination, the average daily autumn temperature is below 0 ℃, indicating that all crops stop Grow and begin to turn yellow. Second, the temperature at 3 ℃ The average daily temperature in spring stabilized by 3 ℃, winter wheat, leek, winter spinach can turn green, spring wheat began sowing; autumn temperature dropped to 3 ℃ below, the crop stops growing, autumn leaves turn yellow. Third, the 5 ℃ boundary temperature The average daily temperature in spring stable by 5 ℃, the early spring crops began sowing, such as early spring vegetables and oil crops; fall temperatures fall below 5 ℃, crop growth is slow. Again every year from the spring to autumn temperature of 5 ℃ between the period, known as farming period. Fourth, the 10 ℃ boundary temperature The average daily spring temperature by 10 ℃ stable, is a variety of crops can grow after sowing heat index, the average daily temperature in autumn is less than 10 ℃, crop photosynthesis strengthened, the speed of maturation.