How long does it take for the temperature of beans to reach 3 to 5 degrees Celsius

Bean seeds usually take 15 to 20 days to germinate at a soil temperature of 3 to 5 degrees Celsius, and the actual time is affected by factors such as soil moisture, seed quality, light conditions, and soil cover thickness.

Beans belong to warm loving crops, and their germination rate is significantly slowed down in low temperature environments. The temperature range of 3 to 5 degrees Celsius is close to the minimum critical temperature for soybean germination. At this time, the metabolic activity of the seeds is weak, and the physiological process of the embryonic root breaking through the seed coat will be delayed. If the soil moisture is maintained at around 60% and there is no standing water, high-quality seeds with high maturity can still complete germination, but uneven emergence may occur. Excessive soil cover during sowing can further prolong germination time, and it is recommended to control it within 2 to 3 centimeters. If encountering continuous rainy weather leading to a sudden drop in soil temperature, or using old seeds stored for more than two years, the germination time may be extended to more than 30 days or even rotten seeds. In some areas, covering with plastic film during early spring sowing can increase soil temperature by 2 to 3 degrees and shorten the germination period to 10 to 15 days. Soaking seeds in warm water for 6 to 8 hours before sowing can activate seed enzyme activity, but temperatures exceeding 50 degrees Celsius can burn the embryos.

It is recommended to choose sunny weather for sowing, deeply plow the soil and apply sufficient decomposed organic fertilizer before sowing. Avoid frequent watering during germination, and improve soil permeability by loosening the soil shallowly. If the seedlings do not emerge after 25 days, the seeds should be checked for mold and replanted in a timely manner. Bean sprouts have poor cold resistance during the seedling stage, and temporary small arch shelters need to be built for protection in case of spring cold.