Evaluating the Economic Feasibility of Combined Biochar, Lime, and Inorganic Fertilizer Rates for Garlic (Allium sativum L.) Production in Gimbi District, Western Ethiopia

Abstract

Garlic is one of the most significant vegetable crops; however, western Ethiopian agricultural land soils are limited by acidic soil, and garlic yield and profit margins continue to be low. The objective of the current experiment was to determine whether the economic viability of garlic production in Gimbi, Western Ethiopia, could be supported by the simultaneous application of biochar, lime, and inorganic fertilizer. The experiment comprised 14 treatments laid out in a RCBD with 3 replicates. The use of combined coffee husk biochar (CHB), soil test‐based value lime (STV), and inorganic fertilizer (NPSB) rates at comb4 and comb11, respectively, resulted in the maximum net benefit costs of 955,461.25 ETB ha−1 in farm 1 and 1,086,776.22 ETB ha−1 in farm 2, whereas costs were incurred with total variable costs of 21,317.75 ETB ha−1 and 16,038.78 ETB ha−1, respectively. The treatments with the highest marginal rates of return in farms 1 and 2 were those that included CHB, STV, and NPSB at comb4 (marginal rate of return = 266,932.80%) and comb12 (marginal rate of return = 29,558.12%), respectively. The difference in economic benefit may have originated from the soil buffer capacity response to ameliorant rates, as the soils of farms 1 and 2 were strongly acidic and very strongly acidic soils. This variation influences plant nutrient uptake, biomass yield, and yield components by enhancing the fertility characteristics of the soil. Therefore, the combined CHB, STV, and NPSB rates at comb4 per hectare in strongly acidic soils and comb12 per hectare in very strongly acidic soils could result in the highest economic return rate for the production of garlic and improve soil fertility. Since only two locations were studied, multilocation research is needed to give a firm recommendation.