By Scout Nelson
Soybean growth and seed yield are the result of a plant’s genetic potential and how it interacts with environmental conditions and farm practices. Understanding the growth stages is vital for making timely decisions and improving crop success.
Soybeans grow through vegetative (VE to Vn) and reproductive (R1 to R8) stages. Early stages include emergence (VE), where the seed absorbs water, sprouts roots, and pushes cotyledons above ground. At VC, the plant begins photosynthesis using unifoliolate leaves. By V1 to V6, trifoliolate leaves develop, and nodules form, helping the plant fix nitrogen.
Soybeans are either indeterminate, like most northern varieties, or determinate, common in the south. Indeterminate types continue vegetative growth during early flowering, while determinate types stop once flowering starts.
Flowering begins at R1 (first bloom) and progresses through R2 (full bloom), followed by pod development stages R3 (3/16-inch pods) and R4 (3/4-inch pods). From R5 (beginning seed) to R6 (full seed), rapid nutrient and water use occurs, and stress during this time can significantly reduce yield.
At R7 (beginning maturity), pods turn brown and seeds lose green colour. By R8 (full maturity), 95% of pods are mature and ready for harvest.
Key practices for success include selecting the right variety, planting at the correct depth (1–1½ inches), ensuring proper soil fertility, managing pests, and using inoculants if soybeans haven’t been planted recently. Also, avoid placing fertilizer directly in the furrow to prevent salt injury.
Minimizing stress during critical stages, especially from R4 to R6, helps protect seed yield. Timely management and understanding each stage of growth will lead to a healthy soybean crop and high productivity.
Photo Credit: istock-ds70
Categories: North Dakota, Crops, Corn, Soybeans