Optimization of lime application to improve potato (Solanum tuberosum L.) productivity in northwestern Amhara, Ethiopia

The study was conducted to ascertain the ideal lime rate for the production of potato at Banja and Machakel districts in acid hot spot areas. The experiment comprised twelve levels of calcium carbonate (CaCO3) lime (rate (0 %, 11.1 %, 12.5 %, 14.3 %, 16.7 %, 20 %, 25 %, 33.3 %, 50 %, 75 %, 100 %, 125 %) that were set up using three replications and a randomized complete block design and studied the tuber yield and soil chemical properties (RCBD. The application of lime rates did not significantly affect the tuber yield of Potato. However, the application of 14.3 % lime at Banja gives 6.41 t.ha-1 and 4.51 t.ha-1 tuber yield advantage over the control at year one site one (Y1S1) and year two site two (Y2S2) respectively. Similarly, the application of 20 % lime at Machakel provides 4.04 t.ha-1, 1.13 t.ha-1, and 0.94 t.ha-1 tuber yields than the control treatment at year one site one (Y1S1), year two site one (Y2S1) and year two site two (Y2S2) respectively. On the other hand, soil properties were changed by the application of lime. This might be due to the reclamation activity of lime through the substitution reaction of (CaCO3) with aluminum (Al+3) and (H+1) on soil exchangeable sites, which leads to the formation of aluminum hydroxide and water rather than free hydrogen and aluminum. Based on this finding the application minimum lime rate of 14.3 % at Banja and 20 % at Machakel is important for acid reclamation with recommended fertilizer (138 N, 69 P2O5) for potato production. So that based on the finding application of the minimal rates on the respected districts is very important.