Economic and productive analysis of irrigated rice crops using a multicase study

Abstract: The objective of this work was to evaluate the relationship between grain yield and production costs of flood-irrigated rice (Oryza sativa) in the state of Rio Grande do Sul, Brazil, in order to determine the yield range that maximizes the profit of farmers. There are estimations pointing out that the yield range that maximizes the profit for farmers is about 75 and 85% of the yield potential; however, this still needs to be validated for irrigated rice in Brazil. To validate these values, a technical and economic monitoring was carried out for eight farmers of irrigated rice, whose production costs were measured and compared with the mean yield and the percentage of potential yield achieved. To determine the potential yield of each crop, SimulArroz, a process-based model developed for the simulation of rice growth and yield in the South of Brazil, was used. The grain yield achieved by the farmers ranged from 6.3 to 11.0 Mg ha-1 (48 to 83% of the potential yield), costs ranged from R$4,197.00 ha-1 to R$6,227.00 ha-1, and profit ranged from R$-52.00 ha-1 to R$3,599.00 ha-1. Farmers who reach between 69 and 83% of yield potential achieve the highest profitability. The investment planning based on the yield potential calculated by the SimulArroz model can be efficiently adopted for irrigated rice crops.

摘要：本研究旨在评估巴西南里奥格兰德州淹水灌溉栽培稻（Oryza sativa）的籽粒产量与生产成本之间的关联，以确定实现农户利润最大化的产量区间。现有估算指出，农户利润最大化的产量区间约为产量潜力的75%至85%，但该结论尚未在巴西灌溉水稻种植中得到验证。为验证该数值，研究团队对8户灌溉水稻种植户开展了技术与经济监测，测算其生产成本，并将其与实测平均产量及达到的产量潜力占比进行对比。为确定各田块的产量潜力，本研究采用了专为巴西南部水稻生长及产量模拟开发的过程模型SimulArroz。受访农户的实测籽粒产量区间为6.3至11.0吨·公顷⁻¹（对应产量潜力的48%至83%），生产成本区间为4197.00雷亚尔（R$）·公顷⁻¹至6227.00雷亚尔（R$）·公顷⁻¹，利润区间为-52.00雷亚尔（R$）·公顷⁻¹至3599.00雷亚尔（R$）·公顷⁻¹。当种植户的产量达到其潜力的69%至83%时，可获得最高收益。基于SimulArroz模型测算的产量潜力制定的投资规划，可有效应用于灌溉水稻种植。