Glycine max
Sunlight
Full sun — short day plant, flowering triggered by day length (variety-dependent)
Water
450-700 mm per crop. Most critical at flowering through early pod fill (R1-R5).
Soil
Well-drained loam. pH 6.0-7.0. Inoculate with Bradyrhizobium if first time planting soybean in a field.
Temperature
Optimal 25-30°C. Cool temperatures (<15°C) delay emergence and maturity.
Humidity
Moderate. High humidity promotes soybean rust and foliar diseases.
Season
Warm season — 80-150 days depending on maturity group and latitude.
Updated February 2026
Overview
Soybean is the world's most important oilseed crop, providing high-quality protein (40%) and oil (20%). Global production exceeds 370 million tonnes annually, with Brazil, the United States, and Argentina producing 80% of the total. Soybean meal is the dominant protein source in animal feed worldwide. The crop fixes atmospheric nitrogen through symbiosis with Bradyrhizobium japonicum bacteria, making it excellent in rotation with cereals. In sub-Saharan Africa, soybean production is expanding rapidly as a protein source and soil improvement crop. Soybean is also a key ingredient in food products including tofu, tempeh, soy sauce, and soy milk.
Plant Health
Soybean is susceptible to 3 known diseases. Early detection is critical — use the CuraPlant app to scan leaves and get an instant AI diagnosis.
Asian Soybean Rust
Asian soybean rust (Phakopsora pachyrhizi) causes tan to dark brown pustules on leaf undersides, leading to rapid defoliation and 10-80% yield loss. No durable resistance exists. Manage with preventive fungicide applications (triazole + strobilurin) at R1-R2 stage, early planting, monitoring sentinel plots, and observing the vazio sanitário (soybean-free period) in Brazil.
Soybean Mosaic Virus Disease
Soybean mosaic virus (SMV) causes light and dark green mosaic mottling, leaf crinkling, stunting, and seed coat mottling. It is seed-transmitted (up to 5%) and spread by aphids. Manage by planting certified virus-free seed, using resistant varieties (Rsv genes), controlling aphids, and roguing infected plants early in the season.
Downy Mildew
Downy mildew produces angular yellow patches on upper leaf surfaces with grayish-purple fuzzy growth underneath. Caused by Peronospora or Plasmopara oomycetes, it thrives in cool wet weather. Manage with resistant varieties, preventive mancozeb or copper sprays, good air circulation, and avoiding overhead irrigation. It requires free water to infect — keep leaves dry.
Cultivation Guide
Inoculate seed with Bradyrhizobium japonicum if planting in new soybean fields
Select maturity group appropriate for your latitude
Plant at 45-60 cm row spacing, 300,000-400,000 plants/ha
Monitor for soybean rust from R1 (flowering) and apply preventive fungicide if detected regionally
Harvest when 95% of pods are brown and seed moisture is 13-15%
Rotate with cereals (maize, wheat) for disease break and nitrogen credit
Companion Planting
Strategic companion planting reduces pest pressure, improves pollination, and can significantly increase yields.
Climate & Regions
Active climate zones for Soybean are highlighted below.
Tropical
Suitable
Subtropical
Suitable
Temperate
Suitable
Mediterranean
Not typical
Highland
Not typical
Arid / Semi-arid
Not typical
Specific Zones & Regions
Common Questions
Soybean grows best during the warm season — 80-150 days depending on maturity group and latitude.. It requires optimal 25-30°c. cool temperatures (<15°c) delay emergence and maturity. and full sun — short day plant, flowering triggered by day length (variety-dependent). In tropical regions with consistent warmth, it can often be grown year-round with proper irrigation.
Soybean is commonly affected by Soybean Rust, Soybean Mosaic Virus, Downy Mildew. Regular crop monitoring, good air circulation, avoiding overhead irrigation, and using disease-resistant varieties are the most effective prevention strategies.
Soybean grows best in well-drained loam. ph 6.0-7.0. inoculate with bradyrhizobium if first time planting soybean in a field.. For irrigation: 450-700 mm per crop. most critical at flowering through early pod fill (r1-r5).. Maintaining proper soil moisture without waterlogging is critical — Soybean is sensitive to both drought stress and root rot from excess water.
Soybean grows well alongside maize. These companions help repel pests, improve pollination, or provide ground cover. Avoid planting near onion, garlic, which can inhibit growth or share susceptibility to the same pests and diseases.
CuraPlant
Scan any leaf with your phone and get an instant AI diagnosis, treatment guide, and prevention plan — even offline.
