About
Soybean (Glycine max) is a warm-season annual legume domesticated in East Asia and now central to global protein and oil systems. Bushy plants reach 30 to 120 cm (1 to 4 feet) with trifoliate leaves and self-fertile flowers that mature into pods packed with high-protein seeds. Maturity groups match latitude and photoperiod across temperate to subtropical production regions. In diversified farms, soy fills summer nitrogen fixation, green manure, and small-scale edamame niches where equipment matches scale. Plant in warm soil after frost risk; short-day types suit lower latitudes. Consistent moisture during pod fill improves yield; drought at flowering causes flower abortion. Inoculate seed with compatible rhizobia when history is absent. Rotate away from close relatives to reduce disease buildup. Harvest edamame when pods are plump and bright green; harvest dry grain when pods rattle and moisture matches storage or processing targets.
Permaculture Functions
- Edible: Immature pods and mature beans diversify protein on farm -- processing into milk or tempeh adds value beyond commodity channels when scale fits.
- Nitrogen Fixer: Root nodules supply residual nitrogen for following crops -- design rotations that capture that credit in soil tests.
- Animal Fodder: Meal and hulls feed monogastrics and ruminants in balanced rations -- amino acid profile complements cereal grains.
- Biomass: Green manure plow-down adds organic matter -- time incorporation to avoid anaerobic piles in wet weather.
- Dynamic Accumulator: Fast growth mines nutrients from fertile topsoil -- straw return recycles phosphorus and potassium if ash or compost loops close.
Companion Planting
Threats & Pressure