Cultivar and planting density effects on biomass yield and forage quality of Moringa oleifera on acidic soils in subtropical Bangladesh

Fodder scarcity and poor forage quality constrain ruminant production in Bangladesh, especially on acidic, low‑fertility soils where land for dedicated forages is limited. Moringa oleifera, a fast‑growing multipurpose tree used as a protein‑rich fodder resource, lacks cultivar‑ and spacing‑specific management guidelines for subtropical acidic soils. We evaluated the effects of cultivar and planting density on biomass yield and foliage quality of M. oleifera grown on acidic terrace soil. Four cultivars (PKM 1, PKM 2, Paraynal and a local black‑seeded landrace, “Black”) were transplanted at four spacings (1.0 × 1.0 to 2.0 × 2.0 ft; 0.30 × 0.30–0.61 × 0.61 m) in a 4 × 4 factorial design. Plant growth, survival, biomass yield, and foliage dry matter (DM) and crude protein (CP) were measured at 180, 220 and 260 days after transplanting. Variety, spacing and their interaction significantly affected growth and yield traits. Biomass per hectare increased as spacing narrowed within the tested density range; at 1.0 × 1.0 ft, PKM 1 and Black produced the highest cumulative yields, whereas approximately three-quarters reduced yields at 2.0 × 2.0 ft. Foliage DM ranged from 19–24% and CP from 14.6–19.9% of DM, with modest spacing effects but clear cultivar differences. Under this single‑site, first‑year study, PKM 1 and Black at 1.0 × 1.0 ft produced the greatest biomass and protein yield per unit area, while Paraynal at 1.5 × 1.5 ft showed lower biomass but relatively higher crude protein concentration. Multi‑year evaluation is required to confirm long‑term performance.