Response of Growth, Yield, and Yield Components of Teff [ <i>Eragrostis tef</i> (Zucc.) Trotter] Varieties to Blended NPS Fertilizer Rates in Bule Hora Woreda, Ethiopia

Teff holds significant importance in Ethiopia, yet it is yielding low due to limited adoption of improved varieties, soil fertility issues, and the absence of fertilizer recommendations tailored to specific locations. The experiment was conducted in Bule Hora Woreda during the 2023 primary growing season to evaluate the response of teff varieties to different levels of blended NPS fertilizer and identify the most economically viable application rate. The study utilized a factorial combination of two varieties, Boset and Tsedey, alongside five levels of NPS fertilizer (0, 50, 100, 150, and 200 kg ha −1 ) within a randomized complete block design (RCBD) with three replications. Findings revealed that teff variety and NPS fertilizer rates had a significant ( p &lt; 0.01) influence on days to panicle emergence, physiological maturity, plant height, and phosphorus uptake. Whereas the panicle length, productive tillers, aboveground dry biomass, grain yield, straw yield, lodging index, and 1000 kernel weight were significantly ( p &lt; 0.01) affected by NPS fertilizer rates alone. Thus, the highest dry biomass (10,207.7 kg ha −1 ), grain (2182 kg ha −1 ), straw (8025.7 kg ha −1 ), and 1000 kernel weight (0.3 g) were observed at an application of 150 kg NPS ha −1 . The interaction of variety and NPS fertilizer had a significant influence on the total number of tillers and nitrogen and sulfur uptake. Moreover, grain yield showed positive correlations with most parameters, suggesting their contribution to yield, except for days to panicle emergence, maturity, and 1000 kernel weight. Furthermore, applying 150 kg of NPS ha −1 led to a high net benefit with a high and acceptable marginal rate of return (MRR). The study concluded that growing Boset and Tsedey varieties with 150 kg NPS ha −1 is economically optimal for teff cultivation. Therefore, the use of 150 kg NPS ha −1 fertilizer is recommended for optimal production of these teff varieties in the study area and other regions with comparable agroecology.