Teff is one of the important crops grown in the southern region. Experiments were conducted at
Bobicho research site (Hossana), Areka and Awassa on Profondic Luvisols, Haplic Alisols, and Vitric
Andosols, respectively, to determine NP fertilizers requirement for tef production. Urea and triple
super phosphate (TSP) were used as sources of N and P, respectively, at Hossana; whereas urea and
diammonium phosphate (DAP) were used at Awassa and Areka as sources of N and P, respectively.
Nitrogen was applied at rates of 0, 23, 46 and 69 kg/ha; whereas P was applied at 0, 10, 20, 30 and 40
kg/ha. Factorial randomized complete block design (RCBD) was used in three replications in all cases.
Teff varieties DZ- 01- 354, DZ-01-196 and Dhabi, which are late, medium and early maturity groups,
respectively, were used at Areka and Awassa; whereas another medium maturity group variety ‘Ajora-
1’ was planted at Hossana. There was no response to any type of fertilizer irrespective of varietals
variations for tef production at Awassa. At Areka, highly significant grain yield difference (up to 20
kg/ha) was obtained for P application, but there was no response to either N alone or its interaction
with P. Additional grain yield of 394 kg/ha was obtained from application of the first 10 kg/ha P over
the check. Highest value cost ratio (VCR) of 10.43 was obtained with application of 10 kg/ha P
followed by 3.54 with 20 kg/ha P, after which the economic return declined sharply. Application of P
up to 30 kg/ha highly significantly increased teff grain yield at Hossana. Both N and P, when applied
separately, also significantly increased straw yield, but their interaction did not. Phosphorus
application showed strong positive correlation with soil P, grain yield and straw yield of teff at
Hossana. Highest VCR of 10.83 was obtained with the application of the first 10 kg/ha P. Value cost
ratio continuously decreased with increasing levels of P up to 30 kg/ha resulting in positive economic
return, where further increase of P level led to negative return. In general, on the basis of the results
obtained, there is no need of applying any type of fertilizer for teff production at Awassa. Application
of P up to 30 kg/ha is recommended for teff production at Hossana; whereas, only up to 20 kg/ha P is
recommended at Areka.