Unlocking Tef Potential: Assessing Yield-Limiting Nutrients Based on Topographic Position in Tehulederie District, Eastern Ethiopia.

Abstract

Nutrient status of soils in Ethiopia varies among different landscapes, but fertilizer recommendations are broad and mostly N and P based. Fine-tuning fertilizer recommendations and crop yield variability within and between landscapes attracted research attention in Ethiopia and across the globe. A field study was conducted in 2021 in the Tehuledere district of the South Wollo Zone of the Amhara Region to identify major yield-limiting nutrients for tef across three different landscape positions in a catena slope of 0-5%, 5-15%, and >15%. Fertilizer rates of 80, 57,7,30,1 and 0.3 Kg/ha of N, P2O5, S, K20, Zn, and B respectively were evaluated. The randomized complete block design was used. Dunckun's multiple range tests was employed for comparison of treatment means for those which were statistically significant. Analysis indicated that micronutrients (Zn, B), potassium (K), and sulfur (S) did not significantly influence the yield, whereas N and P were critical limiting factors for yield. N and P exclusion led to significant yield losses, and their doubling of application to 150% of recommended rates highly enhanced tef grain yields across all slopes. This indicates the need for better management of N and P in tef production, while current emphasis on secondary and micronutrients may be unnecessary in the study region. Other research should be conducted to determine specific rates of N and P application at the study area and other similar agroecologies, further focusing on potential micronutrient deficiencies on hill slopes.