Australia’s farmers are among the most efficient in the world, despite a relatively large gap between potential and achieved water-limited grain yield. With wheat yield gaps typically > 1.7 t/ha or 50% of the water-limited yield, it is important to investigate the degree to which this gap may be attributable to (rational) subprofit-maximising input levels in response to risk and risk aversion in many major grain-growing regions, particularly those with lower and more variable rainfall. Here, we use a set of 14 case study sites across the Australian wheatbelt to examine the risk-return profile of several agronomic management practices and show the extent to which the farmers’ risk attitude determines their decision-making. Using a novel profit-risk-utility framework that incorporates crop simulation, probability theory, finance techniques and risk-aversion analysis, we were able to better demonstrate how farmers might select practices that manage economic risk across sites ranging from low to high rainfall. Results varied with risk preference and yield potential. However, there are real opportunities to close the yield gap by adopting non-limiting or near non-limiting nitrogen fertiliser practices and controlling fallow weeds. We show for the first time that yields associated with current best practice can be surpassed for most levels of risk aversion by adopting an emergent practice of optimising the site-specific time of sowing and matching variety to time of sowing. For some sites and risk profiles, the emerging best practice package which includes additional N fertiliser is also profitable under risk. We also propose a modified integrated framework for yield gaps. Here, we distinguish allocative input constrains due to risk aversion from those due to access to resources, and we account for an innovation gap where the current agronomic frontier is shifted upwards by growers successfully, implementing new technologies that are not yet part of current best practice.

中文翻译：

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单产潜力决定了澳大利亚小麦种植者弥补单产缺口同时减轻经济风险的能力

尽管潜力与实现水限制的谷物产量之间的差距相对较大，但澳大利亚的农民还是世界上最有效率的农民之一。由于小麦单产缺口通常> 1.7吨/公顷或限水单产的50％，因此重要的是要研究这种缺口在多大程度上可归因于（合理的）次利润最大化的投入水平，以应对风险和规避风险在许多主要的谷物产区，特别是降雨量较低且变化较大的地区。在这里，我们使用了整个澳大利亚小麦带上的14个案例研究站点，研究了几种农艺管理实践的风险回报特征，并显示了农民的风险态度在多大程度上决定了他们的决策。使用结合了作物模拟，概率论的新颖的获利风险-实用框架，金融技术和风险规避分析，我们能够更好地证明农民如何选择从低雨量到高雨量的站点管理经济风险的做法。结果随风险偏好和潜在收益而变化。但是，通过采用非限制性或接近非限制性的氮肥措施并控制休耕杂草，确实有机会缩小单产差距。我们首次证明，通过采用优化现场特定播种时间并使品种与播种时间相匹配的紧急实践，可以在大多数风险规避水平上超过与当前最佳实践相关的产量。对于某些场所和风险状况，包括额外的氮肥在内的新兴最佳实践方案也可在风险中获利。我们还为收益差距提出了一个经过修改的综合框架。在这里，我们将风险规避所导致的分配输入约束与资源获取所造成的分配输入约束区分开来，并解决了创新差距，在这种差距中，种植者成功地将当前的农学前沿转移到了上游，实施了尚未成为当前最佳实践一部分的新技术。 。