Wheat (Triticum Aestivum L.) Response to Applied Potassium on Two Contrasting Soil Types (Vertisols and Cambisols) in The Central Highlands of Ethiopia

Abstract Background: A field experiment was conducted at Basonawerana district, Amhara regional state on two major soil types for three consecutive years to determine the effect of application of potassium fertilizer on yield and yield components of wheat and to verify the soil fertility and fertilizer recommendation Atlas of the study site. Six levels potassium were applied (0, 15, 30, 45, 60 and 75 kg K ha-1). At each potassium levels, a balanced nutrient of 92 kg N, 30 kg P, 30 kg S, 2 kg Zn, 0.5 kg Cu and 0.5 kg B ha-1 were applied. The experiment was laid out in a randomized complete block design with tree replications. Result: The analysis of variance showed that all the measured parameters were Significant influenced by year, soil type and the interaction of year x soil type. The highest grain yield, which was observed from cambisols during the first year was increased grain yield by 176.7 % (3954 kg ha-1) compared with the lowest yield observed from vertisols during the third year. Similar trend was also observed in straw yield and harvest index. On the other hand, all the measured parameters was non-significant influenced by K rate, interaction of K rate x soil type and year x K rate x soil types. Numerically, the highest yield (3878.9 kg ha-1) was observed from the highest K rate. However, the trend was not consistent. Conclusion: application of different rates of potassium fertilizer brings any significant growth and yield response on two soil types of the study sites. So, application of this fertilizer is not recommended for the crop with such high K soil status.