Yield-limiting nutrients for enhancing teff production in contrasting landscape positions and rainfall contexts

Multiple nutrient-omission field experiments were conducted in 2020 and 2022 across different landscape positions and rainfall contexts to investigate teff yield response to nutrient application. The treatments included All(B) (i.e., blended fertilizer containing N, P, K, S, Zn and B), All(C) (i.e., compound fertilizer with the same nutrients), All(I) (i.e., individual fertilizers for each nutrient), All(B)-K, All(B)-S, All(B)-Zn, All(B)-B (i.e., All(B) minus the individual nutrients specified), NP, 50% and 150% of All(B), and a control without nutrients. These treatments were arranged in a randomized complete block design with two to three replicates. A linear mixed model was used to determine the effects of landscape position, rainfall context, and nutrients on teff yield. Results revealed significant differences in teff yield response to nutrients in different landscape positions and rainfall contexts. In a high rainfall area, the highest grain yield (1.52 t·ha–1) was recorded from 150% of All(B), with grain yield increments of 6.3%, 10.3% and 154% compared to All(B), NP, and the control, respectively, and 3.2, 5.0 and 84.2% in a medium to low rainfall area. Omitting K, S, Zn, or B, or all four nutrients resulted in the yield penalties of 5.9%, 5.2%, 1.6%, 3.0% and 3.3%, respectively, under high rainfall, and 2.0%, 3.6%, –2.3%, 0.5% and 1.7% in medium to low rainfall contexts compared to All(B). N and P were the most yield-limiting nutrients under all landscape positions and rainfall contexts. Overall, identifying yield-limiting nutrients and their optimal use is vital for enhancing nutrient use efficiency and yield, helping producers achieve rewarding economic returns. Further research is suggested with soil tests across soil types and agroecological zones to determine appropriate NP rates and monitor the need for other nutrients for teff yield and quality.