Optimizing Planting Space and Nitrogen Inputs for Sustainable Forage Production of Mombasa Grass ( Megathyrsus maximus Jacq.) under Cut and Carry System

Forage scarcity and poor nutritional quality of traditional fodders continue to challenge sustainable livestock production, particularly in resource limited and climate vulnerable regions. This study evaluated the interactive effects of planting space (PS) and nitrogen (N) fertilization on the yield and quality of Mombasa grass ( Megathyrsus maximus Jacq.). Two year field experiment was conducted in cropland conditions using a factorial randomized complete block design with three planting spaces (30, 60, 90 cm) and four N levels (0, 50, 100, and 150 kg N ha −1 ). Results showed that narrower spacing (30–60 cm) combined with 100 kg Nha −1 significantly improved forage yield, crude protein (CP) content, and dry matter accumulation, with the marginal gains seen at higher N level (150 kg ha −1 ). Wider spacing increased individual plant biomass and CP but reduced total forage yield. The 100 kg N ha −1 treatment achieved similar productivity to 150 kg N ha −1 , indicating a potential threshold for economically efficient fertilization. This is the first known attempt to evaluate Mombasa grass in cropland systems under integrated spacing and nutrient management. These findings provide a practical basis for the farmers to improve forage production for their livestock while reducing excessive inputs in tropical and sub‐tropical environment. This study contributes to sustainable agriculture by identifying an efficient combination of N input and planting density that enhances forage yield and nutritional quality in Mombasa grass and supports resource efficient N use, reducing N losses and environmental impacts. The findings also promote the diversified forage sources with livestock feed security in low input regions.