Planting Density Modulates Growth and Biomass Allocation of Cowpea (Vigna Unguiculata [L.] Walp) in Iron Industry Effluent-Contaminated Soil: Planting Density and Cowpea Growth under Effluent Contamination. JUST. Published online September 1, 2026:121-133. doi:10.4314/w7hps817