Soy is an annual herbaceous plant, with a good root system and abundant nodulation. Its erect stem has a variable length that can go from 50 cm to 1.5m. Its leaves are alternate trifoliate with oval leaflets and its very small and abundant white or purple flowers. Soybean pods are hairy and usually contain two to three grains.
It is not a very widespread crop in Spain, but there are approximately 1,500 hectares of soybeans, which have an annual production of 4,300 tons. Worldwide, the United States produces approximately 47% of soybeans, followed by Brazil (20%), Argentina (12.5%) and China (9.5%).
Soy is a plant that prefers soils of medium consistency, deep and fertile, although in poor soils it can continue to give high yields. In siliceous or limestone soils it can thrive well, provided there is enough organic matter to promote nutrient uptake.
In relation to the climate, soy is a rustic plant that is moderately resistant to cold and not prolonged droughts. Flooded soil can cause production losses, although it adapts to different climates. When the plant is young it is less resistant to climatic variations, but in its adult phase it acquires a certain resistance to these changes.
Soy has medium-high water requirements, although it does not tolerate waterlogging of the soil well. Generally they need to consume about 600-700 liters of water per kg of dry matter.
Soybean varieties are distributed in groups ranging from 0 to IV, depending on whether they are short cycle like group 0 (110 days) or long cycle like group IV (147 days). Within the same group, they are given another figure, which helps them to place them within that group. For example, the Panter variety (III-8) has a longer cycle than the Katai variety (III-1). In Spain, the most widely cultivated varieties are Akashi (II-9), Azzurra (I), Canton (I-9), Gallarda (II), Katai (III-1), Panter (III-8), among many others