Abstract:
Currently, the government of Ethiopia supplying fertilizers in the form of N, P, S, Zn & B. However, many researchers argue that N and P are the only yield-limiting nutrients. The study was
conducted to identify yield-limiting nutrients of tef and to assess the inherent nutrient supplying
status of Vertisols. The experiments were carried out during the 2020/2021cropping season
under screen house, on-station and on-farm conditions at Yilmana Densa district of Amhara
region, Ethiopia. Tef (Quncho variety) was used as a test crop. This trial contained ten treatments, control, PKSZnB, NKSZnB, NPSZnB, NPKZnB, NPKSB, NPKSZn, NPKSZnB, NP and
NPS. Each pot with a depth of 18.5 cm and a surface area of 0.033 m2 was filled with 5 kg of
soil. The pot trial was laid out in a completely randomized design (CRD) while the field trials
laid out in a completely randomized block design (RCBD) with three replications. Yield-limiting
nutrients were identified through nutrient omission trial. The data were analyzed using SAS
version 9.0 and treatment means separated by using LSD at P ≤ 0.05.The result revealed omission of N and P highly significantly (P˂ 0.01) reduced grain yield, straw yield and yield components of tef in all experiments. However, the absence of potassium, sulfur, zinc, and boron
did not show significant (P ˂ 0.05) yield reduction. Before planting soil analysis of TN (0.126%
on-station and 0.125% on-farm) was low. The Av.P (3.89 mg kg-1on-station and 4.24 mg kg-1
on-farm) content of the soil was also very low. The lowest grain and biomass yields (2.2 and
7.9 g/pot under screenhouse), (177.2 and 533.3 kg ha-1 on-station) and (24.9 and 533.3kg ha-1
on-farm) respectively, were recorded from omission of N. However, omission of P resulted in
grain and biomass yields (2.4 and 8.1 g/pot under screenhouse), (191.1 and 1066.7kg ha-1 onstation) and (106.4 and 533.3 kg ha-1 on-farm) respectively. Application of K, S, Zn and B did
not have any effect on tef yield over the applied NP. Based on these results N and P were
identified as the most yield-limiting nutrients of tef. Application of N and P containing fertilizer
is better for tef production.