It is clear that determining the type of product of each area and agricultural planning depend on the climate. One of the characteristics of climate change is temperature variation. The direct effect of heat on the distribution and dispersion of plants over the earth is certain. The sensitivity of plants to high, low and optimal temperatures and their effect on increasing or decreasing vegetative and reproductive growth rates of plants are among the scientific facts that have attracted the attention of most scientists in the field of plant sciences. Soybean product in Gorgan plain is considered as the second dominant cultivation after the wheat, barley and other spring harvestings.
In this research, the author has tried to investigate the role of absolute temperatures in the stages of vegetative and reproductive growth of soybeans by utilizing the theories of scientists, practical analyses, determination of the probability of occurrence of temperatures above the tolerance of plants, and field operations; finally, due suggestions have been made. Furthermore, the effect of temperature on soybean cultivating and its role in increasing or decreasing yield as well as implementation of correct management in terms of selecting appropriate planting dates for agricultural operations have been indicated.