Soya belongs to the papilionaceous flowers or to the leguminous plants and may reach a height of 80 to 100 cm. The flowers are red, white but can also be violet. The beans grow in pods that develop in clusters of 3 to 5 cm with each pod usually containing 2 or 3 beans. These beans are sometimes big or small, long, round or oval. The color can also vary. Some are yellow, others are green but can also be brown or violet and some are even black or with spots..

The soybean fields are brown when harvesting starts because the leaves of the plant are dry before the beans are mature. The remaining plant has only stems with pods.

Soybean plants can be grouped into basically two main types, determinant and indeterminant, both grown mostly in temperate climates. The determinant varieties will flower at a certain time of the year, basically when the days begin to shorten. Indeterminant varieties will continue to flower and put on fruit until the weather dictates that it is time to curtail plant growth. There are many different varieties which allow soybeans to be produced in different maturity zones that stretch from North Dakota (latitude 49?N) to Louisiana (latitude 30?N) in the United States.

One of the most important agronomic characteristics of soybeans is that it can take nitrogen from the air and "fix" it to be used by the soybean plant.