Abstract:
'he h;qh demand for crop land in the semi-arid highlands of northeastern Ethiopia, arising from hig|-
lopulation pressuic, has led to a decrease in fallow periods and an increase in continuous cultivation of
ereals without replenishment of nutrients to the soil. Consequently, poor soil fertility is the main
onstraint of crop production for the resource poor fanners in this area. A field experiment was conducted
a assess the role of integrated use of animal manure (AM) and mineral fertilizers on soil fertility
irameters and grain yield and yield components of wheat. The experiment was laid out in a random izec
omplete block design in three replications where the treatments were composed of the factoria
ombination of the different rates of AM (0, 5 and 10 ton ha'1) and 50% of the locally recommendec
nineral fertilizer rates (0 and 23 Kg ha'1 nitrogen; 0 and 10 Kg ha'1 phosphorus). The results showed thai
he sole application of AM significantly improved soil physical properties at different soil depths. The use
>f \M in integration with mineral fertilizers has also improved most of the soil physical properties. The
oil chemical properties were affected by both application of AM alone and integrated with minera
ertilizers. ncreased soil fertility parameters were observed with increased levels of AM application
iowever. the application of mineral fertilizer has shown inconsistent effects on soil fertility parameters
he yield and yield components of w'heat had increased significantly with the integrated application o
AM with mineral fertilizers. The sole application of AM had also increased these crop parameters. The
□plication of AM at a rate of 5 and 10 ton ha'1 gave a yield advantage of 15.4 and 28.6% over the nonnanured
plots, respectively. The highest grain yield of wheat (2796.4 kg ha'1) was obtained by the
.ombined application of 10 ton ha'1 AM and 50% the locally recommended mineral fertilizer rates (23/10
ivg ha'1 N/P). In conclusion, the application of 5 to 10 ton ha'1 AM with 50% the locally recommendec;
nineral fertilizer rates could have positive effects both on soil fertility parameters and wheat yield anc
yield components.
