Effects Of Integrated Vermicompost And Npsb Fertilizers, And Cutting Intervals On Dry Matter Yield And Nutritional Value Of Alfalfa (Medicago Sativa) In South Sodo Woreda, East Gurage Zone, Centeral Ethiopia

Abstract

This study was conducted in South Sodo Woreda, East Gurage Zone, and Central Ethiopia, to evaluate the effects of integrated NPSB fertilizer and vermicompost, and cutting intervals on the growth, biomass yield, and nutritional value of alfalfa (Medicago sativa L.). Two factors factorial experiment was laid out in a randomized complete block design (RCBD) with 16 treatment combinations (T1: Control (0kg/ha NPSB fertilizer+0 ton/ha vermicompost (VC)); T2: 0 kg/ha NPSB+2.5 ton/ha VC; T3: 0 kg/ha NPSB+5 ton/ha VC; T4: 0 kg/ha NPSB+7.5 ton/ha VC; T5: 50 kg/ha NPSB+0 ton/ha VC; T6: 50 kg/ha NPSB+2.5 ton/ha VC ; T7: 50 kg/ha NPSB+5 ton/ha VC; T8: 50 kg/ha NPSB+7.5 ton/ha VC; T9: 100 kg/ha NPSB+0 ton/ha VC; T10: 100 kg/ha NPSB+2.5 ton/ha VC; T11: 100 kg/ha NPSB+5 ton/ha VC; T12: 100 kg/ha NPSB+7.5 ton/ha VC; T13: 150 kg/ha NPSB+0 ton/ha VC; T14:150 kg/ha NPSB+2.5 ton/ha VC; T15: 150 kg/ha NPSB+5 ton/ha VC; T16: 150 kg/ha NPSB+7.5 ton/ha VC) and three CUTTING INTERVALS s (1st cut, 2nd cut and 3rd cut) with three replications. Soil samples were analyzed for physicochemical properties before sowing, and agronomic parameters such as plant height, tiller number, leaf count, leaf-to-stem ratio, and days flowering were recorded. Biomass yield was assessed at 50% flowering, while forage quality was determined by analyzing it for crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL). The results demonstrated that integrated fertilizer management significantly (P achieved the highest dry matter yield (10,57t/ha representing 39.08% increase over the control. Cutting intervals also influenced yields, with the third cut producing 27% higher biomass than the first. Economic analysis showed T11 yielded the highest net benefit (350,600 ETB/ha) and marginal rate of return (4,510%). Additionally, higher fertilizer rates promoted early flowering in T11 in which 50% of flowering achieved at 60.21 days compared to 74 days in the control. These findings highlight the synergistic effects of organic and inorganic fertilizers in improving alfalfa productivity and nutritive value. Integrating 100 kg NPSB/ha with 5 t/ha vermicompost (T11) proved to be the most effective treatment, supporting its adoption as a sustainable fertilizer management strategy for enhanced forage production.