How to grow soybean
Know more about this plant species
The soybeans are annual herbaceous plants originally from the Far East (China, Japan, Indochina). The seeds have been part of the Far East diet since ancient times. However, they are eaten nowadays all around the world in different forms, mainly entire, ground to flour or milk and it is also a valuable oil resource. The nutritional value is highly considered especially for vegetarians and vegans, due to the presence of complete proteins, which means that it contains all nine essential amino acids for the body.
Theses seeds grow in groups of 3 generally, inside a fruit called silique or pod produced by the species Glycine max. This is a species that belongs to the Fabaceae family, also called Leguminaceae, together with kidney beans (Phaseolus vulgaris), lentils (Lens culinaris), chickpeas (Cicer arietinum), lupins (Lupinus albus) and peanuts (Arachis hypogaea) among others. The most common fruit that all those species produce are siliques containing a different range of seeds number.
They present a vegetative circle of around 5 months, being able to reach 1.5 meters tall with branches. To obtain the best growing conditions for those plants you can obtain a personalized fertilization programme for your crops using the SMART Fertilizer software. The frits when dry are around 5 cm long and, if you are not familiar with its flower, they grow axillary and in groups presenting a yellowish and withe or purple colour.
According to studies, 100 grams of cooked soybeans provide 127 kilocalories, 11.12 grams of protein, 5.67 of fat, 9.95 of carbohydrates and 3.8 grams of fibre. Although, improved varieties may reach even 42% of its dry weigh in protein and 22% in oil.
Edaphoclimatic requirements
Taking into account the favourable temperature, hours of light, fertilization and soil characteristics are essential to obtain the highest proficiency from your soybean plants. In this case, the optimal temperature for the sowing period is between 15 to 18 °C. Then, the highest yield will be obtained at 30 °C or at least when the temperature is between 20 and 30 °C. Despite these plants can survive the frost even when the conditions are as low as -4 °C, it would cause serious trouble in the plant physiology being lethal if prolonged in time.
The water requirements vary depending on the stage. To germinate, the seeds require a high moisture but not to be soak since overwatered seeds would present fractures and germinate poorly. It is estimated that providing them with 500 mm of water is optimal for crops planted in good conditions. On the other hand, adult plants prefer a lower humidity, decreasing the optimal values to 300 mm of water that could be reached just from rainfall in the humid temperate zones or by irrigation in other cases.
You can find in the SMART Fertilizer software a personalized fertilization program for your soybean crop, obtained from precise calculations we would do for you. Those plants prefer neutral or acid soils with a pH around 6. Nitrogen is the most absorbed nutrient since around 75 kg are required per ton of grains. However, between 30 to 70 % of the total required is obtained by biological nitrogen fixation (BNF). The BNF is produced by a symbiotic association in the soybean roots with rhizobia such as Bradyrhizobium japonicum and Bradyrhizobium elkanii, that fixes the atmospheric nitrogen in root-nodules. Besides, potassium is the second most absorbed nutrient followed by calcium. The requirement for those nutrients is around 40 and 16 kg per ton of grains respectively.
The roots length could reach one meter deep, but it normally has around 50 cm. For the radicular and aerial parts to grow properly, it is recommended to prepare the rows 70 cm apart and a distance of 12 cm between plants. It will let not only be favourable for the root development but will also let the adult plants to get the sufficient sunlight for the photosynthesis avoiding leaves overlap when the aerial structure is optimally mature to produce flowers. Due to this, spacing the plants this way, will provide the highest yield.
Harvesting and profitability
To have an overview, the yield you would get having soybeans as a main crop will be around 4,5 t/ha. Having it a secondary crop the mean yield is 3,1 t/ha. In 2018, the upward price got closed to 480 €/t. However, in some areas, when cultivating these plants, the yield obtained was much lower than expected and, in those cases, researchers investigated the reasons why. In Paraguay it was determined that the weather was not the only factor responsible of this issue. In this study published by the Food and Agriculture Organization of the United Nations (FAO) the agronomist Eduardo Blasina expressed that the yield may be also reduced due to the sowing season or fertilization, because the potassium and sulphur required were not taken into account. It indicated the importance of a proper fertilization even in crops like this with low requirement. With the SMART Fertilizer software, you can easily get rid of this problem and obtain the maximum profitability.
- Recommends the ideal fertilizer mixture/ blends
- Saves up to 50% on fertilizer costs
- Comprehensive data on hundreds of crop varieties
- Interprets test results for any extraction method
