Abstract:
Use of inappropriate fertilizer type and rate, cultivation of unimproved low yielding
varieties and low soil fertility are among the major constraints limiting the productivity
of wheat in Ethiopia in general and in particular to the study area. Thus, field experiment
was initiated to evaluate the effects of blended NPS fertilizer rates on yield components
and yield of bread wheat varieties and to identify economically feasible rates of blended
NPS fertilizer in the study area. The experiment was laid out in RCBD with three
replications in which three bread wheat varieties (Ogolcho, Jalane and Sanate) and five
levels of blended NPS fertilizer (0, 50, 100, 150 and 200 kg ha-1) in a factorial
combination were evaluated. The results showed that all characters of the bread wheat
varieties were significantly affected (p<0.01) by main effect of variety and blended NPS
fertilizer. The highest (8.67cm) and the lowest (6.62cm) spike length, (64.56) and (44.56)
kernels per spike were obtained from plots received 200 kg NPS ha-1 and from control,
respectively. While, the highest (0.43) and the lowest (0.36) harvest index was obtained
from 150 kg ha-1 NPS. The two main factors interaction affect only number of total tillers,
number of productive tillers, above ground biomass, grain and straw yield. The highest
(379.6) and the lowest(128.1) productive tillers was recorded from the combined
application rate of 150 and 0 kg ha-1 NPS fertilizer with Sanate and Jalane varieties,
respectively. Whereas, the highest (6424 kg ha-1) and the lowest (2701 kg ha-1) grain
yield was recorded from the combined application rate of 200 and 0 kg NPS ha-1
fertilizer with Sanate and Jalane varieties, respectively. The partial budget analysis
indicated that the highest net benefit of 82710 ETB ha-1 with a marginal rate of return
2305.8% obtained by planting of Sanate variety with the application of blended NPS
fertilizer at a rate of 150 kg ha-1. Based on the result of this study, it can be concluded
that the application of 150 kg ha-1 NPS and the growing of Sanate variety could be better
choice of the farmers of the study area to obtain high yield with higher rate of return.
However, since the experiment was conducted for one season at one location, it is
suggested that the experiment has to be repeated over seasons and locations using this
and other improved bread wheat varieties in order to give a comprehensive
recommendation.
