Abstract:
Malt Barley is important cash-crop in Ethiopia, whose yield was constrained by minimum use of improved varieties, and declining soil fertility due to nutrient depletion. A field experiment was conducted to investigate the effects of blended fertilizer rates on growth, yield and quality of malt barley varieties at Debre Berhan District Central High Land of Ethiopia. The experiment was laid out in Randomized Complete Block Design with factorial arrangement with three replication and consisted of ten fertilizer treatments: (T1) NP (70&20) used as control, (T2) NP(S1=7) , (T3) NP(S2=14), (T4) NP(S3=21) , (T5) NPS1(B1=0.1), (T6) NPS2(B2=1.1), (T7) NPS3(B3=2.1), (T8) NPS1B1(K1=50), (T9) NPS2B2 (K2=100) and (T10) NPS3B3 (K3=150) kg ha-1 and two malt barley varieties (Ibon174/03 and Holker). The analysis of variance showed highly significant differences on number of tillers and effective tillers plant-1, numbers of kernel spike-1, thousandkernel weight, above ground biomass, straw yield and grain yield were observed due to blended fertilizer rates and varieties. Compared to the recommended NP fertilizers, the straw and grain yield were increased by 27.95% and 26.90% respectively with the application of blended fertilizer NPS3B3K3 (Treatment 10). Similarly, as compared to the recommended NP fertilizers, the straw and grain yield were increased by 17.1% and 11.4% respectively with the application of blended fertilizer NPS3 (Treatment 4). The variety Ibon174/03 had the highest mean grain yield (4.71 t ha-1), while variety Holker had the lowest mean grain yield (4.02 t ha-1). The analysis of data revealed significant difference due to interaction effects of varieties by blended fertilizers on grain yield, straw yield, nitrogen uptake and protein content. Variety Ibon174/03 at NPS3B3K3 rate gave the highest grain yield (5.20 ton ha-1) but the maximum economical grain yield (4.89 t ha-1) was obtained from Ibon174/03 variety with treatment number 4 (70, 20, 21 kg NPS3 ha-1) fertilizer application. The economic analysis revealed that the highest marginal rate of return (MRR %) of 3258.78 and 1324.94 recorded from the application of treatment 4 (70, 20 & 21 kg NPS3 ha-1) for both varieties Ibon174/03 and Holker respectively. Therefore, application of treatment 4 (70, 20 &21 kg NPS3 ha-1) is recommended to use by farmers as an alternative soil management option for malt barley production around Debre Berhan. However, as this is a one season experiment at one location, similar experiment has to be repeated over multi locations and seasons of the district with the inclusion of more blended fertilizer rates and varieties to reach at a conclusive result.
