Economic analysis and sustainability of systems with agricultural rotations in rain-fed and irrigated by pivot

摘要

Irrigation is an investment, where the value is included as a cost in the profitability analysis. The aim of this study is to evaluate and compare the economic profitability of four agricultural rotations, rain-fed and irrigated. Crops for agricultural rotations were: corn, soybean, wheat, and as a green rye grass bridge. The experimental design was randomized blocks, with three repetitions, in a factorial scheme. Irrigation was applied by central pivot and the reference of evapotranspiration was calculated based on Penman-Monteith/FAO methodology. The expenditures were analyzed with the average annual costs per hectare, where the fixed costs, variable costs, were discriminated, calculating the prices of inputs, services and land value. The following financial indicators were determined: net present value, internal rate of return, benefit / cost ratio, investment recovery period, annual equivalent cost and the equilibrium point, estimated in 4, 8, 12, 16 and 20 years. The agricultural rotation of corn and rye grass in rain-fed was the one that showed the most economically unfavorable scenario since it did not provide security to invest in it. The agricultural rotation that presented the most favorable scenario was corn, wheat, soybeans, rye grass, showing more profitable financial indicators in both conditions, short periods of recovery of investment and low points of equilibrium.