In fields of undulating topography, where rainfed crops experience different degrees of water stress caused by spatial water variations, yields vary spatially within the same field, thus offering opportunities for variable rate application (VRA) of nitrogen fertilizer. This study assessed the spatial variations of yield gaps caused by lateral flows from high to low points, for rainfed wheat grown in Córdoba, Spain, over six consecutive seasons (2016–2021). The economic implications associated with multiple scenarios of VRA adoption were explored through a case study and recommendations were proposed. Both farm size (i.e., annual sown area) and topographic structure impacted the dynamics of investment returns. Under current policy-price conditions, VRA adoption would have an economic advantage in farms similar to that of the case study with an annual sown area greater than 567 ha year⁻¹. Nevertheless, current trends in energy prices, transportation costs and impacts on both cereal prices and fertilizers costs enhance the viability of VRA adoption for a wider population of farm types. The profitability of adopting VRA improves under such scenarios and, in the absence of additional policy support, the minimum area for adoption of VRA decreases to a range of 68–177 ha year⁻¹. The combination of price increases with the introduction of an additional subsidy on crop area could substantially lower the adoption threshold down to 46 ha year⁻¹, making VRA technology economically viable for a much wider population of farmers.

在地形起伏的田地中，雨养作物因空间水分变化而经历不同程度的水分胁迫，同一田地内的产量在空间上存在差异，从而提供了氮肥可变施用率 (VRA) 的机会。本研究评估了在西班牙科尔多瓦连续六个季节（2016-2021 年）种植的雨养小麦由高点到低点的横向流动造成的产量差距的空间变化。通过案例研究探讨了与采用 VRA 的多种情景相关的经济影响，并提出了建议。农场规模（即年播种面积）和地形结构都会影响投资回报的动态。在当前的政策价格条件下，^-1。然而，当前能源价格、运输成本的趋势以及对谷物价格和化肥成本的影响提高了 VRA 在更广泛的农场类型中采用的可行性。^{在这种情况下，采用 VRA 的盈利能力会提高，并且在没有额外政策支持的情况下，采用 VRA 的最小面积会减少到 68–177 公顷 year −1}的范围。价格上涨与对作物面积引入额外补贴相结合，可以将采用门槛大幅降低至 46 公顷年^-1，使 VRA 技术在经济上对更广泛的农民群体可行。